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1
McGinley, Susan. "The Weighing Lysimeter Project." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/622350.
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Stanley, Mary Helen. "Suction Cup Lysimeter Method for Extracting Pine Bark Substrate Solution." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/42244.
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The objective of this study was to determine the effectiveness of suction cup lysimeters (SCL) in extracting substrate solution from pine bark substrates. Lysimeter types tested were 4.8-cm diameter with a ½ or 1-bar air-entry value (AEV) and 2.2-cm diameter also with a ½ or 1-bar AEV. Sufficient volume could be obtained when a vacuum pressure of 30, 40 or 50 cb was applied to lysimeters with a minimum extraction time of five minutes. The 2.2-cm lysimeters were found to be suitable for extracting solution if smaller sample volumes were needed. To determine effect of vacuum pressure and extraction time on volume extracted, the 4.8-cm ½-bar lysimeters were installed in containers with pine bark substrate and Quercus phellos L. (willow oak) trees. Volumes extracted were somewhat erratic and not strongly dependent upon centibars of vacuum or extraction time. Lysimeters immersed in water demonstrated that variability was not due to individual lysimeters, but to the coarse nature of the pine bark substrate. Substrate EC levels were not affected when volume of substrate solution extracted by the SCL's varied from 10 to190 ml.â
To determine the effectiveness of SCL's to monitor nutrient status of container-grown shade trees, two-year-old container-grown willow oak trees were grown in a pine bark substrate and fertilized with 0, 50, 100, 150, 200, 250 or 300 grams Osmocote Plus Northern (15N â 3.9P â 9.8K). Plant height and trunk diameter increased with up to 200 grams of Osmocote per container. There was a good relationship between solution EC and plant growthMaster of Science
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Amter, Steven 1956. "Injection/recovery lysimeter technique for unsaturated zone soil-water extraction." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/191933.
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Current methods of vacuum lysimetry only allow water samples to be collected from the unsaturated zone in relatively wet soils. This thesis presents the results of computer simulation and field testing of a promising new technique that allows water samples to be collected regardless of antecedent moisture content. Injection of a chemically neutral fluid will increase the moisture content of a relatively dry soil, allowing the collection of a sample that contains soil water diluted in the injection fluid. This can be analyzed to yield qualitative chemical data. Although injection was found to alter soil structure and soil-water chemistry in some instances, the technique can be used in existing lysimeters, without modification, to repeatedly obtain partially representative soil-water samples containing inorganic and organic compounds. Injection lysimetry is best suited to those applications, such as tracer tests and detection of containment leakage, where absolute chemical concentrations are not required.
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Goldenfum, Joel Avruch. "Soil water flow processes : a critical evaluation using numerical simulations and lysimeter data." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339212.
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Tirado-Corbala, Rebecca. "A Lysimeter Study of Vadose Zone Porosity and Water Movement in Gypsum Amended Soils." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1290111537.
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Amankwah, Edward Akwasi. "Predictive Modeling of Organic Pollutant Leaching and Transport Behavior at the Lysimeter and Field Scales." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1195122485300-99209.
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Soil and groundwater pollution has become a global issue since the advent of industrialization and mechanized agriculture. Some contaminants such as PAHs may persist in the subsurface for decades and centuries. In a bid to address these issues, protection of groundwater must be based on the quantification of potential threats to pollution at the subsurface which is often inaccessible. Risk assessment of groundwater pollution may however be strongly supported by applying process-based simulation models, which turn out to be particularly helpful with regard to long-term predictions, which cannot be undertaken by experiments. Such reliable predictions, however, can only be achieved if the used modeling tool is known to be applicable. The aim of this work was threefold. First, a source strength function was developed to describe the leaching behavior of point source organic contaminants and thereby acting as a time-dependent upper boundary condition for transport models. For general application of these functions dimensionless numbers known as Damköhler numbers were used to characterize the reaction of the pollutants with the solid matrix. Two functions were derived and have been incorporated into an Excel worksheet to act as a practical aid in the quantification of leaching behavior of organic contaminant in seepage water prognoses. Second, the process based model tool SMART, which is well validated for laboratory scale data, was applied to lysimeter scale data from two research centres, FZJ (Jülich) and GSF (München) for long term predictions. Results from pure forward model runs show a fairly good correlation with the measured data. Finally, the derived source term functions in combination with the SMART model were used to assess groundwater vulnerability beneath a typical landfill at Kwabenya in Ghana. The predicted breakthrough time after leaking from the landfill was more than 200 years considering the operational time of the facility (30 years). Considering contaminant degradation, the landfill would therefore not cause groundwater pollution under the simulated scenarios and the SMART model can be used to establish waste acceptance criteria for organic contaminants in the landfill at KwabenyaSeit dem Beginn der Industrialisierung und der mechanisierten Landwirtschaft wurde die Boden- und Grundwasserverschmutzung zu einem weltweiten Problem. Einige Schadstoffe wie z. B. PAK können für Jahrzehnte oder Jahrhunderte im Untergrund bestehen. Um diese Probleme behandeln zu können, muss der Schutz des Grundwassers basierend auf der Quantifizierung potentieller Gefährdungen des zumeist unzugänglichen Untergrundes erfolgen. Risikoabschätzungen von Grundwasserverschmutzungen können jedoch durch die Anwendung prozess-basierter Simulationsmodelle erheblich unterstützt werden, die sich besonders im Hinblick auf Langzeitvorhersagen als hilfreich erweisen und nicht experimentell ermittelbar sind. Derart zuverlässige Vorhersagen können jedoch nur erhalten werden, wenn das verwendete Modellierwerkzeug als anwendbar bekannt ist. Das Ziel dieser Arbeit bestand aus drei Teilen. Erstens wurde eine Quellstärke-funktion entwickelt, die das Ausbreitungsverhalten organischer Schadstoffe aus einer Punktquelle beschreibt und dadurch als zeitabhängige obere Randbedingung bei Transportmodellen dienen kann. Im Hinblick auf die allgemeine Anwendbarkeit dieser Funktion werden als Damköhler-Zahlen bekannte, dimensionslose Zahlen verwendet, um die Reaktion von Schadstoffen mit Feststoffen zu charakterisieren. Zwei Funktionen wurden abgeleitet und in ein Excel-Arbeitsblatt eingefügt, das ein praktisches Hilfsmittel bei der Quantifizierung des Freisetzungsverhaltens organischer Schadstoffe im Rahmen der Sickerwasserprognose darstellt. Der zweite Teil dieser Arbeit beinhaltet die Anwendung des prozessbasierten und mittels Laborexperimenten validierten Modellwerkzeugs SMART für Langzeitprognosen auf der Lysimeterskala anhand von Daten zweier Forschungszentren, FZJ (Jülich) und GSF (München). Ergebnisse reiner Vorwärtsmodellierungsläufe zeigten gute Übereinstimmungen mit den gemessenen Daten. Im dritten Teil wurden die erhaltenen Quellstärkefunktionen in Kombination mit dem SMART-Modell eingesetzt, um das Grundwassergefährdungspotential unter einer typischen Deponie in Kwabenya, Ghana, einzuschätzen. Die vorhergesagten Durchbruchszeiten nach einer Leckage in der Deponie betragen über 200 Jahre bei einer Betriebszeit von 30 Jahren. Unter Berücksichtigung des Schadstoffabbaus verursacht die Deponie somit keine Grundwasserverunreinigung im Rahmen der simulierten Szenarien und das SMART-Modell kann verwendet werden, um Schadstoffgrenzwerte für organische Schadstoffe in der Deponie in Kwabenya festzulegen
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Kelemen, Julia C. "Effects of tree encroachment on the water balance of a Scottish raised mire : a lysimeter study." Thesis, University of Dundee, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320593.
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Johansson, Pontus. "Utvärdering av fosforläckageefter stallgödsling med hjälp av lysimeterteknik : Evaluation of phosphorus leaching aftermanure application using lysimeter techniques." Thesis, Mark och miljö, SLU, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-111172.
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Based on laboratory studies with lysimeters, the concentrations of dissolved reactive phosphorus
(DRP) and particulate phosphorus, which is the main part of other P (OVRP), has been studied in
percolating water. The experiment was conducted through irrigation of small soil columns
containing clay topsoil from an experimental field in Västergötland. Three rain simulations were
consecutively performed. DRP concentrations in the percolating water ranged between 0.2 - 0.3
mg·L
clearly related to the phosphorus concentration in the soil, measured in a soil extract of
ammonium lactate (P-AL). Concentrations of OVRP were relatively low and ranged between
0.12 and 0.16 mg·L
was not proven and the experiment may reflect how a relatively slow percolation of water may
release DRP. In contrast, from observed fields with drainage systems quite high concentrations of
OVRP are typically recorded. This is generally explained by fast flows through macropores in the
soil and through the drain tile systems.
Solid manure was applied to the lysimeters equal to a normal agricultural load (30 tons per ha),
and thereafter another three rainfall were simulated. The load of manure increased the leaching of
DRP approx. 7 times. The largest increase was observed from the soils with the highest P-ALnumbers.
The relative boosts of DRP after manure application increased linearly relative to the PAL
number of the soil and with a high correlation coefficient. Thus the results from the manure
addition indicated that the soil with highest phosphorus concentrations released proportionally
more phosphorus than soils with low P-AL numbers. The studies demonstrate the importance of
adjusting the load of manure to the soil phosphorus content. Presently the spreading of manure is
only restricted by the number of cattle/cultivated land, not to the P-AL number of the soil.
-1. The amount of DRP percolating from four soils with different fertilization history was-1 in the percolating water passing through the topsoil. Any macropore flow
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Hu, Qing. "Migration and plant uptake of radionuclides in laboratory soil columns and field lysimeter with contaminated water tables." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287371.
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Mangwende, Tapera Elias. "Quantifying nitrogen leaching in wheat (Triticum aestivum L.) using lysimeter stable isotope conservative tracer and modelling techniques." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/65909.
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Nitrogen (N) leaching is one of the important pathways that leads to water pollution, and previous studies have highlighted the difficulty in measuring it. The purpose of this study was to evaluate different techniques used to quantify nitrate-N (NO3-N) leaching load and determine fertiliser N use efficiency (FNUE). Lysimeter and field trial sites were planted with wheat (Triticum aestivum) (PAN3400 cultivar) at the University of Pretoria Experimental Farm, Hatfield, Pretoria. Two weighing lysimeters and a drain gauge were installed at the lysimeter trial site. Water content sensors and suction cups (SCs) were installed at 0.15, 0.3, 0.5 and 0.7 m depths in the weighing lysimeters and close to the drain gauge, while SCs, wetting front detectors (WFDs) and water content sensors were installed at 0.25 and 0.5 m in the field trial site. The crop was fertilised with 200 kg N ha-1 at both sites, but no fertiliser was applied on unfertilised control plots at the field trial site. High density drip irrigation was used at both sites, and bromide (Br-) was applied to all field plots at 0.020 kg m-2. Water was sampled from the SCs, WFDs and the bottom of weighing lysimeters and drain gauge to determine soil water NO3-N and Br- concentrations. Soil samples collected before and after the trial, and plant samples taken at tillering, flowering and physiological maturity were analysed for plant N% and stable 15N natural abundance using a mass spectrometer. Phenological and growth data from the lysimeter trial were used to calibrate Agricultural Production Systems sIMulator (APSIM) model for the first time (according to our knowledge) on wheat in South Africa. The model was then validated using data from the field trial. The drain gauge drained more frequently and in greater amounts than the weighing lysimeters, and NO3- was observed in drainage water from the drain gauge, but was undetectable from the weighing lysimeters drainage possibly because of saturated bottom layer that promoted denitrification. Based on stable 15N natural abundance, the FNUE was 68%, so the fertilised crop did not use 32% of the applied fertiliser. Good correlation was noted between the flag leaf and total plant N% at physiological maturity, indicating that flag leaf can be used to determine the FNUE without requiring whole plant analysis. The potential NO3-N leaching determined using a Br- conservative tracer was 51.5 kg ha-1 season-1. In fertilised plots, the calibrated model predicted NO3-N leaching of 22.7 kg ha-1 season-1, which was slightly lower than the drain gauge measured NO3-N leaching 24.9 kg ha-1 season. Therefore, the drain gauge shows excellent promise in quantifying N leaching but will require further testing under a range of cropping systems. Since the measured drain gauge and simulated NO3-N leaching agreed, and variables such as grain yield, total above dry matter, leaf area index and soil water content were reasonably simulated, the APSIM model can be applied to wheat cropping systems to improve N management decisions. The model confirmed that proper timing of N applications can reduce leaching losses, but further tests are required in several wheat growing agro-ecological zones to explore N management options that minimise N leaching losses. Even without measurements and/or modelling of N losses and crop uptake, results of this study for wheat indicate that the 15N stable isotopes can be used on its own to estimate FNUE, but more studies from different soil types and on wheat varieties are required to verify the trends observed in this study.Dissertation (MSc (Agric))--University of Pretoria, 2017.
Agricultural Economics, Extension and Rural Development
MSc (Agric)
Unrestricted
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Klein, Markus. "Langjähriger Wasserhaushalt von Gras- und Waldbeständen Entwicklung, Kalibrierung und Anwendung des Modells LYFE am Gross-Lysimeter St. Arnold /." [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961677082.
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Osberg, Peter Martin. "Lysimeter measurements of salal understory evapotranspiration and forest soil evaporation after salal removal in a Douglas-fir plantation." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26018.
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Two weighing lysimeters were constructed in a 23-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand. The salal (Gaultheria shallon Pursh.) understory was mechanically removed from a 30 x 40 m plot and one lysimeter was located at the center of this plot to measure daily forest soil evaporation (E[sub s]). For 8 consecutive days, in August 1984, E[sub s] ranged between 0.08 and 0.34 mm d⁻¹ which was 15-18% of the daily total stand evapotranspiration. In July 1985, after removing salal from the second lysimeter, which was positioned under a less dense tree canopy, E[sub s] was 0.34 - 0.41 mm d⁻¹ which was 17-21% of the daily whole stand evapotranspiration. Forest floor diffusive resistances (r[sub co]), computed by rearranging the Penman-Monteith equation, were found to range between 900 and 3500 s m⁻¹.
The measured daily evapotranspiration rate from the understory (E[sub t]) with salal present was 0.60 - 0.84 mm d⁻¹, which was equivalent to 30-42% of the daily stand evapotranspiration.
The dependence on windspeed of the bulk aerodynamic resistance (s m⁻¹) to vapour transport (r[sub A]) between the salal canopy and measurement height (0.3 m above the top of the salal canopy) was found to be r[sub A] = 25.2 ū[sup – 0.554], where ū is the mean windspeed (m s⁻¹) at measurement
height. Approximately 70-75% of r[sub A] was estimated to be attributable to the leaf boundary-layer resistance. The evaporation rate from wet foliage was found to be 5 times greater than the transpiration rate from dry foliage exposed to similar meteorological conditions. Analysis of the relative importance of net available energy flux density and advective processes in determining the latent heat flux density from the understory yielded a range of Q values between 0.15 and 0.22. The vapour pressure deficit below the tree canopy was found to be largely determined by the vapour pressure deficit above the tree canopy, with very little local adjustment.Land and Food Systems, Faculty of
Graduate
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Jebellie, Seyed Jalal. "A lysimeter study to determine fate and transport of three agricultural herbicides under different water table management systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ36990.pdf.
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Jebellie, Seyed J. "A lysimeter study to determine fate and transport of three agricultural herbicides under different water table management systems /." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34649.
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Subirrigation systems are generally used in humid areas to provide suitable moisture conditions for plant growth. These systems can also be used to reduce pesticide loadings from agricultural lands, since they tend to keep the discharging waters within farm boundaries for extended periods of time. This allows for greater pesticide microbial and chemical degradation.A three-year field lysimeter study was initiated to investigate the role of subirrigation systems in reducing the risk of water pollution from the three most commonly used herbicides in Quebec, namely atrazine (2-chloro-4[ethylamino]-6[isopropylamino]-1,3,5-triazine), metribuzin (4-am ino-6(1,1-di meth yl eth yl)-3-(meth yl thio)-1,2,4-tria zin-5(4H)-one), and meto lach lor (2-chlo ro-N-(2-eth yl-6-methyl phen yl)-N-(2-meth oxy-1-meth yl eth yl)acet amide). Eighteen PVC lysimeters, 1 m tall x 0.45 m diameter, were packed with a sandy soil. Three water table management treatments, i.e. two subirrigation treatments with constant water table depths of 0.4 and 0.8 m, respectively, and a free drainage treatment in a completely randomized design with three replicates were used. Grain corn (Zea mays L.) and potatoes (Solanum tuberosum L.) were grown on lysimeters, and herbicides were applied each year at the locally recommended rates at the beginning of each summer. Soil and water samples were collected at different time intervals after each natural or simulated rainfall event. Herbicides were extracted from soil and water samples and were analyzed using Gas Chromatography.
From the three years results (1993--1995), it has been concluded that all three herbicides were quite mobile in this sandy soil, as they leached to the 0.85 m depth below the soil surface quite early in the growing season. This suggests that if the drainage effluent or seeping waters from sandy soils of agricultural lands in southern Quebec drain freely, they may be considered to be a serious non-point source of pollution to the water bodies. The results have also shown that herbicide concentration decreased with soil depth as well as with time, meaning that the higher herbicide residues were found at top layers, and soon after the herbicide application. The herbicide mass balance study revealed that when the drainage effluent was kept within the lysimeters under the subirrigation setup, there was a statistically significant reduction of atrazine and metribuzin residues (shorter half lives) in the adsorbed and liquid phases. However, the reduction in metolachlor concentration under the subirrigation system was not statistically significant. These findings suggest that subirrigation, combined with certain herbicides can significantly reduce the herbicide loadings from corn and potato farms in southwestern Quebec, and become environmentally beneficial.
A computer simulation model (PRZM2), was used to simulate atrazine, metribuzin, and metolachlor leaching in the lysimeters, under subsurface drainage conditions. The simulated values for all three chemicals in most of the cases followed the leaching pattern of observed data. But the model either under- or over-estimated the herbicide concentrations in the soil. This could have been caused by simplistic instantaneous linear adsorption/desorption of herbicides, and inadequacy of conventional Darcian approach for the treatment of matrix flow.
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Marcoline, Joseph R. "Investigations of water and tracer movement in covered and uncovered unsaturated waste rock." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1011.
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A better understanding of the hydrogeology of mine waste rock and cover systems is essential for the quantification, prediction and reduction of metals loading to the receiving environment. A series of experiments were conducted on an instrumented intermediate-scale waste rock pile at the Cluff Lake Mine in Saskatchewan to investigate the changes in flow and solute transport within coarse waste rock under three different surface conditions. Following these studies, the waste rock pile was deconstructed, structures were mapped, and samples were collected for physical characterization and pore water extraction. The internal structure of the waste rock pile was more important than the texture and topography under the free-dumped and ripped/leveled surface, while the surface condition was found to be the dominant control on spatial and temporal variability of outflow from the waste rock with the covered surface. Data from a deuterium tracer test, lysimeter outflow, and from TDR probes were used to derive estimates of the maximum and an average pore water velocity through the uncovered and the covered waste rock. An average pore water velocity through the matrix materials of the uncovered waste rock was approximately 1.5 m/yr and maximum preferential flow velocities were as high as 5 m/day. The post-cover pressure wave velocity of 0.1 to 1 m/day is inferred from outflow and TDR data, and average pore water velocities (0.39 m/y and 0.73 m/y) are calculated by the water flux and tracer methods, respectively. The distribution of the tracers in pore water and the internal structure were mapped during a detailed deconstruction of the waste rock pile and attempts were made to link the data to the spatial and temporal patterns of lysimeter outflow. The pore water chloride concentrations and the deuterium values did not provide conclusive data necessary to link the spatial and temporal patterns observed in the lysimeter hydrographs to internal structure; however, it provided insight into the internal flow mechanisms and water residence times.
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Henry, William Nathan. "Evapotranspiration, Consumptive Water Use, And Responses To Self-Imposed Drought Of Three Warm Season Grasses Grown In A Semi-Arid Region." Thesis, The University of Arizona, 2007. http://hdl.handle.net/10150/193382.
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Evapotranspiration rates (ET) and consumptive water use (CWU) were measured for three desert turfgrasses using weighing lysimeters with a calcined clay growth medium. Water use rates were compared over a two-year study for 'Sea Isle I' seashore paspalum (Paspalum vaginatum) and A138 desert saltgrass (Distichlis spicata), along with 'Tifway' bermudagrass (Cynodon dactylon x Cynodon transvaalensis). Saltgrass showed elevated leaf canopy temperatures for extended periods before exhibiting visible wilt symptoms while 'Tifway' bermudagrass and seashore paspalum wilted readily, even at relatively high soil water contents. Saltgrass transpired for 11.9 d on average before drought stress was observed. Seashore paspalum maintained leaf turgor, on average 5.6 d without irrigation, whereas 'Tifway' bermudagrass averaged 4.0 d before requiring irrigation. The two-year average Kc values for three grasses before self-imposed drought was expressed by visible leaf wilting were 0.85, 0.79, and 0.74, for A138 saltgrass, 'Sea Isle I' seashore paspalum, and 'Tifway' bermudagrass, respectively.
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Kelly, Harold Lorain Jr 1958. "Remote measurement of turf water stress and turf biomass." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276995.
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Increasing irrigation efficiency on turfgrass could help reduce water consumption on large turf facilities. Two experiments were conducted using perennial ryegrass (Lolium perenne (L.) Derby) to evaluate the potential of using remote sensing to estimate turf water status, predict daily evapotranspiration (ET), and estimate turf biomass. In the first experiment a crop water stress index, utilizing remotely sensed canopy temperature, were used to schedule irrigations on 6 of 10 drainage lysimeters. Three of the remaining lysimeters were irrigated used on meteorological estimates of ET calculated using a modified Penman equation. The results of this experiment were inconclusive due to inconsistent lysimeter drainage characteristics. The second experiment was conducted on a turf green with multiple heights to evaluate the potential for using canopy radiance to estimate turf biomass. These results showed that turf biomass could be estimated from a vegetative index (Red Ratio = Near Infrared/Red radiance) obtained through measurements of canopy radiance (r2 = 0.91).
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Shah, Sanjay Bikram. "Agronomic and Nitrate Leaching Impacts of Pelletized versus Granular Urea." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29201.
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Agronomic and water quality impacts of urea particle size were evaluated through field and laboratory experiments and mathematical modeling. In a two-year field study, corn silage yield, corn nitrogen (N) removal, and nitrate-N (NO₃⁻-N) leaching from urea pellets (1.5 g each) and granules (0.01-0.02 g each) applied at 184 kg-N/ha were compared. A control treatment (no N) and two other N application rates (110 and 258 kg-N/ha) were also included. Urea particle size impact on dissolution rate, dissolved urea movement, mineralization, and N0³-N leaching were evaluated in the laboratory. A two-dimensional (2-D) mathematical model was developed to simulate the fate of subsurface-banded urea and its transformation products, ammonium (NH₄⁺)and NO₃⁻.
With 184 kg-N/ha, corn silage yield was 15% higher (p = 0.02) and corn N removal was 19% higher (p = 0.07) with pellets than granules in the second year of the field study. In the absence of yield response at 110 kg-N/ha, reason for higher yield at 184 kg-N/ha with pellets was unclear. Greater N removal reduced NO₃⁻-N leaching potential from pellets compared to granules during the over-winter period. No urea form response to yield or corn N removal was observed in the first year. In 23 of 27 sampling events, granules had higher NO₃⁻-N concentration in the root zone than pellets, with average nitrate-N concentrations of 2.6 and 2.2 mg-N/L, respectively. However, statistically, NO₃⁻-N leaching from the root zone was unaffected by urea form, probably due to high variability within treatments masking the treatment effects. In October 1997, pellets retained 16% more (p = 0.04) inorganic-N in the top half of the root zone than granules, due to slower nitrification in pellets as was determined in the mineralization study. Slower NO₃⁻-N leaching allowed for greater N extraction by plants. Pellets had lower dissolution, urea hydrolysis, and nitrification rates than granules; however, nitrification inhibition was the dominant mechanism controlling N fate.
The model took into account high substrate concentration effects on N transformations, important for simulating the fate of band-applied N. The model exhibited good mass conservative properties, robustness, and expected moisture and N distribution profiles. Differences in measured field data and model outputs were likely due to uncertainties and errors in measured data and input parameters. Model calibration results indicated that moisture-related parameters greatly affected N fate simulation. Sensitivity analyses indicated the importance of nitrification-related parameters in N simulation, particularly, their possible multiplicative effects. Need for extensive model testing and validation was recognized. The validated 2-D N model could be incorporated into a management model for better management of subsurface-banded granular N. However, the 2-D model is not appropriate for simulating the three dimensional N movement from pellets.Ph. D.
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Rahman, Mohd Shafiqur. "Intensive culture of loblolly pine (Pinus taeda L.) seedlings on poorly drained sites in the Western Gulf region of the United States." Texas A&M University, 2003. http://hdl.handle.net/1969.1/272.
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A significant acreage of poorly drained sites occurs in the Western Gulf region of the United States. These sites experience standing water through much of the winter and spring, resulting in poor seedling survival. In addition, the sites occasionally experience a summer drought that affects tree growth. This study was designed to determine the effects of intensive forest management on seedling growth and physiology, and to enhance seedling performance under these harsh conditions. Fertilization, chemical vegetation control and mechanical site preparation were used in different combinations to test the effects of these intensive forest management tools on seedling above- and below-ground growth, survival, water status, gas exchange attributes, and nutrient concentrations in the foliage and soil solution. Ten sites were established in southern Arkansas in 1998 and 1999 to monitor loblolly pine (Pinus taeda L.) seedling performance in three consecutive growing seasons between 1998 and 2000.
Fertilization, chemical vegetation control and mechanical site preparation increased above-ground growth. Growth increment from mechanical site preparation was comparable to that from fertilization. Survival was not affected by any treatment. Fertilization enhanced root growth, more so in the shallow soil layers. Subsoil bulk density greatly restricted root growth, resulting in decreased above-ground growth. Chemical vegetation control made more soil water available to the seedlings during drought, resulting in increased seedling water potential. The effect of chemical vegetation control on seedling water potential was absent in the early growing season when soil moisture was abundant. Seedlings on plots treated with bedding-plus-fertilizer or bedding alone experienced stomatal closure at times of severe water stress while those treated with chemical vegetation control were able to continue net carbon dioxide assimilation. Fertilization did not increase needle nutrient concentrations, but increased needle weight, thereby increasing total nutrient content. Fertilization increased base cation concentrations in the soil solution, but had no effect on nitrogen and phosphorus concentrations. Intensive forest management was found to be a viable tool for optimum loblolly pine seedling growth and survival on poorly drained sites in the Western Gulf region of the United States.
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Lena, Bruno Patias. "Consumo hídrico do pinhão-manso (Jatropha curcas L.) irrigado e sem irrigação na fase de formação." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-18072013-104451/.
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O conhecimento da demanda hídrica de uma cultura é fundamental para o planejamento da implantação de novas áreas, bem como para a análise da viabilidade econômica de uma cultura em determinada região. A utilização de culturas para fontes de matéria prima alternativa vem sendo altamente estudada nos últimos anos. Dentre muitas, vem se destacando no cenário nacional e mundial a cultura do pinhão-manso (Jatropha curcas L.) para a produção de biodiesel. O consumo de água por parte do pinhão-manso é pouco conhecida, necessitando ser estudada a fim de aprofundar os conhecimentos sobre a cultura e fornecer parâmetros confiáveis para a prática da irrigação. Os objetivos desse trabalho foram determinar a evapotranspiração (ET), a evaporação (E), a transpiração (T), o coeficiente de cultivo (Kc), coeficiente de evaporação (Ke) e coeficiente de cultivo basal (Kcb) do pinhão-manso na fase de formação irrigados por pivô central, gotejamento e sem irrigação na cidade de Piracicaba, SP. O experimento foi realizado na Fazenda Areão da Escola Superior de Agricultura \"Luiz de Queiroz\" da USP durante o período de março de 2012 a abril de 2013. O experimento foi dividido em três tratamentos, sendo: irrigado por pivô central, gotejamento e sem irrigação. A determinação de ET foi realizada por meio lisímetros de pesagem em cada tratamento, contabilizando a variação de massa em função das entradas saídas de água no sistema. A determinação do Kc foi realizada pela razão entre ET e ETo (estimado a partir de dados coletados na estação meteorológicos automática da Fazenda Areão). Por meio de microlisímetros de pesagem, foi determinado E. De posso dos dados de E, foram determinados os valores de T pela diferença de E (determinado no microlisímetro) e ET (determinado no lisímetro). Os valores de Ke e Kcb foram determinados pela razão de E e T por ETo, respectivamente. Os valores de ET variaram, principalmente, em função do método de irrigação. Foi observado uma superioridade dos valores de ET para o tratamento irrigado por pivô central, seguido do tratamento irrigado por gotejamento e sem irrigação. As médias dos tratamentos durante o primeiro ano foram 3,17, 2,82 e 2,82 mm dia-1 para os tratamentos irrigado por pivô central, irrigado por gotejamento e sem irrigação, respectivamente. Essa mesma proporção de ET entre os tratamentos irrigados foi observado nos valores de Kc. A média do período de Kc foi 0,69 e 0,63 para os tratamentos irrigados por pivô central e gotejamento. Essas maiores taxas de ET e Kc do tratamento irrigado por pivô central em relação ao tratamento irrigado por gotejamento foi devido ao método de irrigação por gotejamento ser mais eficiente na utilização de água pelas plantas em relação ao método por pivô central. Nesse método, a água é aplicada de maneira localizada as plantas, diferentemente do método por pivô central, em que a água é aplicada em toda a superfície do solo. Isso faz com que as taxas de E no método por gotejamento seja menor em relação ao pivô central, diminuindo as taxas de ET. De maneira geral, as taxas de E e Ke foram maiores em relação aos valores de T e Kcb durante o período analisado. Isso foi devido as plantas estarem com porte baixo e o solo estar quase por completo exposto as variações atmosféricas, fazendo com que as taxas de E e Ke sejam superiores as de T e Kcb. A média de E e Ke foram 1,85 mm dia-1 e 1,03, respectivamente, e as médias de T e Kcb foram 0,4 mm dia-1 e 0,2, respectivamente.The knowledge of the water demand of a culture is essential for planning of new areas, as well as for the economic viability analysis of a culture in a specific region. The use of crops for alternative feedstock sources has been extensively studied in the last years. Among many, jatropha (Jatropha curcas L.) has been highlighted for biodiesel production in the national and global scenarios. Water consumption by the jatropha is little known, which requires to be studied in order to increase the knowledge and provide reliable parameters for the irrigation practice. The objectives of this study were to determine the evapotranspiration (ET), evaporation (E), transpiration (T), crop coefficient (Kc), evaporation coefficient (Ke) and basal crop coefficient (Kcb) of jatropha in the formation phase irrigated by center pivot, drip and without irrigation in Piracicaba, SP. The experiment was conducted at Areão Farm of Escola Superior de Agricultura \"Luiz de Queiroz\" of USP during March 2012 to April 2013. The experiment included three treatments: center pivot irrigated, drip irrigated and dryland. The determination of ET was made by weighing lysimeters for each treatment, accounting the inputs and outputs of water in the lysimeter system. The determination of Kc was made by the ratio between ET and ETo (estimated from data collected at the automatic meteorological station of Areão Farm). The determination of E was made by microlysimeters and T was determined between the difference of ET and E. Ke and Kcb values were determined by the ratio of E and T by ETo, respectively. ET values varied, mainly, according to the irrigation method. It was observed superiority of ET values for the treatment irrigated by center pivot, followed by the treatment irrigated by drip and without irrigation. The average during the first year was 3.17, 2.82 and 2.82 mm day-1 for the treatment irrigated by center pivot, irrigated by drip irrigated and without irrigation, respectively. The same proportion of ET from irrigated treatments was observed in the values of Kc. In the period, the average of Kc was 0.69 and 0.63 for the treatments irrigated by center pivot and irrigated by drip. These higher rates of ET and Kc of the treatment irrigated by center pivot compared to the treatment irrigated by drip was due to the method of drip irrigation is more efficient in water use by plants in relation to the method irrigated by central pivot. In this method, the water application is made in a localized way, differently in relation to the center pivot method in which water is applied all over the soil surface. This makes E rates given by drip irrigation method lower than the center pivot irrigation method, decreasing its ET averages. In general, rates of E and Ke were higher compared T and Kcb values during the period analyzed. This was explained due the short plants stature and the soil was almost completely exposed to atmospheric variations, causing rates of E and Ke exceed from T and Kcb rates. The average of Ke and E were 1.85 mm day-1 and 1.03, respectively, and the average of T and Kcb were 0.4 mm day-1 and 0.2, respectively.
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Nouri, Hamideh, Edward Glenn, Simon Beecham, Boroujeni Sattar Chavoshi, Paul Sutton, Sina Alaghmand, Behnaz Noori, and Pamela Nagler. "Comparing Three Approaches of Evapotranspiration Estimation in Mixed Urban Vegetation: Field-Based, Remote Sensing-Based and Observational-Based Methods." MDPI AG, 2016. http://hdl.handle.net/10150/618720.
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Despite being the driest inhabited continent, Australia has one of the highest per capita water consumptions in the world. In addition, instead of having fit-for-purpose water supplies (using different qualities of water for different applications), highly treated drinking water is used for nearly all of Australia's urban water supply needs, including landscape irrigation. The water requirement of urban landscapes, particularly urban parklands, is of growing concern. The estimation of evapotranspiration (ET) and subsequently plant water requirements in urban vegetation needs to consider the heterogeneity of plants, soils, water, and climate characteristics. This research contributes to a broader effort to establish sustainable irrigation practices within the Adelaide Parklands in Adelaide, South Australia. In this paper, two practical ET estimation approaches are compared to a detailed Soil Water Balance (SWB) analysis over a one year period. One approach is the Water Use Classification of Landscape Plants (WUCOLS) method, which is based on expert opinion on the water needs of different classes of landscape plants. The other is a remote sensing approach based on the Enhanced Vegetation Index (EVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra satellite. Both methods require knowledge of reference ET calculated from meteorological data. The SWB determined that plants consumed 1084 mmyr(-1) of water in ET with an additional 16% lost to drainage past the root zone, an amount sufficient to keep salts from accumulating in the root zone. ET by MODIS EVI was 1088 mmyr(-1), very close to the SWB estimate, while WUCOLS estimated the total water requirement at only 802 mmyr(-1), 26% lower than the SWB estimate and 37% lower than the amount actually added including the drainage fraction. Individual monthly ET by MODIS was not accurate, but these errors were cancelled out to give good agreement on an annual time step. We conclude that the MODIS EVI method can provide accurate estimates of urban water requirements in mixed landscapes large enough to be sampled by MODIS imagery with 250-m resolution such as parklands and golf courses.
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Souza, Evandro Luiz Corrêa de 1977. "Comportamento do herbicida tebuthiuron em solo de cultivo de cana-de-açucar utilizando lisimetro de drenagem modificado." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257062.
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Orientador: Luiz Lonardoni FoloniDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
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Resumo: O tebuthiuron é um dos herbicidas mais usados no plantio de cana-de-açúcar, no Estado de São Paulo. Estudos têm sido realizados para determinar o índice de lixiviação do tebuthiuron e para monitorar sua presença nos mananciais de águas superficiais e subterrâneas, ainda sem uma conclusão definitiva sobre a questão. Com o objetivo de avaliar, em condições de campo, a movimentação vertical do herbicida Tebuthiuron em Latossolo Vermelho Distroférrico típico, de textura argilosa, característico da cultura da cana-de-açúcar no estado de São Paulo, testou-se a hipótese de que uso do herbicida tebuthiuron, em ambiente controlado, é adsorvido à argila e aos solos com elevado teor de matéria orgânica, apresentando baixa mobilidade vertical e pequeno potencial de contaminação de águas subterrâneas. O trabalho foi conduzido no Campo Experimental da Faculdade de Engenharia Agrícola da UNICAMP, utilizando-se lisímetro de drenagem modificado de 2 m de diâmetro e 3 m de profundidade, com 10 pontos verticais, através dos quais foram coletadas amostras de água da chuva. As 6 primeiras amostras foram coletadas 1 dia após as chuvas, no período de março a julho de 2006 e as 3 últimas, no mês de agosto, após irrigação da área por aspersão, simulando as chuvas de janeiro do mesmo ano. As amostras foram submetidas à Análise Cromatográfica Líquida de Alta Eficiência. Os dados encontrados, correlacionados e avaliados indicaram uma presença decrescente do herbicida nas amostras coletadas ao longo do tempo - de março a agosto de 2006: amostra 1 - 0,020 g i.a. (5,3 %); 2 ¿ 0,016 g i.a. (4,3 %); 3 - 0,015 g i.a. (4,0 %); 4 - 0,014 g i.a. (3,7 %); 5 - 0,014 g i.a. (3,7 %); 6 - 0,007 g i.a. (1,9 %); 7 - 0,002 g i.a. (0,5 %); 8 - 0,001 g i.a. (0,3 %) do total aplicado na área do lisímetro (0,3768 g i.a.), confirmando a hipótese de baixa mobilidade vertical do tebuthiuron em Latossolo Vermelho Distroférrico típico, de textura argilosa , numa curva decrescente ao longo do tempo e indicando, para este solo, pequeno potencial de contaminação das águas subterrâneas
Abstract: Tebuthiuron is one of the most used herbicides in sugar cane, in São Paulo State. Studies have been carried through to determine the tebuthiuron leaching index and to monitor its presence in superficial and groundwater sources, without still a definitive conclusion. With the objective to evaluate, in field conditions, the vertical movement of the herbicide Tebuthiuron in Clayey Distroferric Red Soil, sugar cane crop characteristic in São Paulo State, tested the hypothesis that the use of the herbicide tebuthiuron, in controlled environment, is adsorbed to the clayey and high organic matter soils, showing low vertical mobility and small potential of groundwater contamination. The work was conducted in the Experimental Field College of Agricultural Engineering - UNICAMP, using a modified drainage lysimeter with 2 meters of diameter and 3 meters of depth, with 10 vertical points through which were collected water samples of rain. The 6 first samples had been collected 1 day after rains, from March to July - 2006 and the 4 last ones, in the August month, after irrigation area for aspersion, simulating rains of January in same year. The samples was submitted by High Performance Liquid Chromatography (HPLC).The found, correlated and evaluated data had indicated a decreasing presence of the herbicide in samples collected to long of time ¿ March to August of 2006: sample 1 - 0,020 g i.a. (5,3 %); 2 ¿ 0,016 g i.a. (4,3 %); 3 - 0,015 g i.a. (4,0 %); 4 - 0,014 g i.a. (3,7 %); 5 - 0,014 g i.a. (3,7 %); 6 - 0,007 g i.a. (1,9 %); 7 - 0,002 g i.a. (0,5 %); 8 - 0,001 g i.a. (0,3 %) - total applied in lysimeter area (0,3768 g i.a.), confirming the hypothesis a low vertical mobility of tebuthiuron in Clayey Distroferric Red Soil, clayey texture, in one decreasing curve to the long of time and indicating, for this soil, small potential of contamination of groundwater
Mestrado
Agua e Solo
Mestre em Engenharia Agrícola
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Cunha, Alessandra Troleis da. "Estimativa experimental da taxa de recarga na zona de afloramento do Aqüífero Guarani, para a região de São Carlos - SP." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-18102016-143331/.
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A engenharia hidrológica visa quantificar os parâmetros que envolvem um balanço híbrido. Nesse domínio, a avaliação da taxa de recarga de aqüíferos subterrâneos torna-se relevante, devido ao uso indiscriminado desse recurso híbrido. Com o auxílio de um lisímetro e a aplicação de conceitos teóricos da infiltração, estimou-se a taxa de recarga potencial do Aqüífero Guarani para a região de São Carlos. O lisímetro, instalado na Estação Hidrometereológica do CRHEA, possui uma área de exposição de 3,6 m2 e profundidade de 1,50 m. Para a coleta do volume infiltrado utilizou-se um sistema de drenagem, com destino em um tanque coletor graduado. O lisímetro foi preenchido com solo da zona de afloramento do Aqüífero Guarani (solo arenoso). Houve monitoramento de umidade do solo, dentro do lisímetro e em campo aberto, nas proximidades do local de retirada do solo. Coletaram-se dados de infiltração no período de janeiro de 2002 a janeiro de 2003. A taxa de recarga direta potencial foi estimada em 55,6% da precipitação, para o período em estudo. Análises do comportamento da água no solo demonstraram que a recarga em aqüíferos subterrâneos ocorre somente em períodos de chuva (novembro a março). Para o período seco (abril a outubro) as precipitações esparsas não são suficientes para suprir a deficiência de umidade do solo. O trabalho permitiu, ainda, concluir que os métodos teóricos para estimar evapotranspiração potencial não são adequados em regiões caracterizadas por períodos secos e chuvosos.Hydrologic Engineering quantifies the parameters involving water balance. Thus, the evaluation of aquifers recharge rates is considered a relevant matter due to the uncontrolled use of this type of water resource. The potential recharge rate of Guarani Aquifer for São Carlos area was estimated based on data measured on lysimeter and through the analysis of theoretical infiltration concepts. The lysimeter, assembled at the Hydrometereological Station of CRHEA, is 1.50 m deep and has 3.6 m2 of exposure area. A drainage was used to collect the infiltrated volume, leading it to a graduate collection tank. The lysimeter was filled with soil from the recharge zone of Guarani Aquifer (sandy soil). Soil humidity was monitored inside the lysimeter and at open field, around the area from where the soil was extracted. Infiltration data was recorded between January 2002 and January 2003. Potential direct recharge rate was calculated to 55.6% of the precipitation, for the studied period. Analyses of water behavior in the soil have shown that aquifers recharge occurs only in rainy periods (from november to march). Throughout the droughts (from april to october), sparse precipitations are not enough to compensate the humidity deficiency in the soil. It was also possible to conclude that the theoretical methods for estimation of potential evapotranspiration are not suitable for regions characterized by droughts and rainy periods.
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Lena, Bruno Patias. "Crop evapotranspiration and crop coefficient of jatropha from first to fourth year." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-06012017-111443/.
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The determination of crop coefficient (Kc) with adequate methodology is important to quantify regional water requirement. Jatropha (Jatropha curcas L.) Kc is still unknown and this information will be essential to provide reliable irrigation parameters, as well as for crop zoning. The objective of this study was to determine jatropha actual crop evapotranspiration (ETc) and Kc from 1st to 4th growing year, and correlate Kc with leaf area index (LAI) and cumulative thermal unit (CTU). The experiment was performed from March 2012 to August 2015 at \"Luiz de Queiroz\" College of Agriculture (ESALQ)/University of São Paulo (USP), at Piracicaba city, SP, Brazil. The experiment was divided into center pivot, drip, and rainfed treatments. Two large weighing lysimeters (12 m2 each lysimeter) per treatment were used to determine jatropha ETc (one plant per lysimeter). Reference evapotranspiration (ET0) was determined by Penman-Monteith method from a weather station data situated close to the treatments. Daily Kc was determined for the two irrigated treatments by the ration between ETc and ET0 (Kc=ETc/ET0). LAI was determined using the LAI-2200 plant canopy analyzer, which was previously calibrated for jatropha canopy type. In all growing years, LAI was almost zero at the beginning of vegetative stage, increasing until a maximum during productive stage, and decreasing to zero in the leaf senescence stage. Annual ETc trend during the three growing was very similar, which was explained by the different growing periods and the LAI variation. In the 1st year Kc was 0.47 for both treatments. In the 2nd, 3rd, and 4th years Kc ranged from 0.15 to 1.38 for center pivot treatment and from 0.15 to 1.25 for drip treatment. Kc average in 2nd, 3rd, and 4th years during vegetative and productive growing periods was 0.77, 0.93, and 0.82 for center pivot treatment, respectively, and 0.69, 0.79, and 0.74 for drip treatment, respectively. The relationship between Kc and LAI for the center pivot treatment was adjusted to a logarithmical equation with coefficient of determination (R2) and root mean square error (RMSE) of 0.7643 and 0.334, respectively. For the drip treatment R2 was 0.8443 and 0.2079, respectively. In all three years analyzed, Kc related to CTU by a 3rd degree polynomial equation for both treatments.A determinação de coeficiente de cultivo (Kc) com metodologia adequada é essencial para quantificar o consumo hídrico de cultivos em diferentes regiões. Valores de Kc do pinhão-manso (Jatropha curcas L.) ainda não foram determinados e essa informação é muito importante para auxiliar o manejo de irrigação de maneira adequada. O objetivo desse estudo foi determinar a evapotranspiração (ETc) e Kc do 1º ao 4º ano de cultivo do pinhão-manso, e correlacionar Kc com o índice de área foliar (IAF) e a soma da unidade térmica (SUT). O experimento foi realizado de março de 2012 à agosto de 2015 na Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ)/Universidade de São Paulo (USP), na cidade de Piracicaba, SP, Brasil. O experimento foi divido nos tratamentos irrigados por pivô central, gotejamento e sem irrigação. Foram utilizados dois lisímetros de pesagem (12 m2 de superfície em cada lisímetro) por tratamento para realizar a determinação de ETc (uma planta por lisímetros). A evapotranspiração de referência (ET0) foi determinado pelo método de Penman-Monteith a partir de dados meteorológicos coletados na estação meteorológica localizada ao lado do experimento. Valores diários de Kc foram determinados nos tratamentos irrigados pela razão entre ETc e ET0 (Kc=ETc/ET0). IAF foi determinado utilizando o equipamento LAI-2200 Plant Canopy Analyzer, que foi previamente calibrado para adequar as características do dossel do pinhão-manso. Em todos os anos avaliados, o IAF foi quase zero durante o início do período vegetativo, aumentando os valores conforme a planta começou a se desenvolver até atingir valores máximos durante o período produtivo, decrescendo os valores até zero no estádio de desenvolvimento de senescência foliar. A variação anual de ETc no 2º, 3º e 4º ano foi muito similar, explicado pelos diferentes períodos de desenvolvimento da cultura e a variação de IAF no ano. No 1º ano, Kc foi 0,47 para os dois tratamentos irrigados. No 2º, 3º e 4º ano, Kc variou de 0,15 a 1,38 no tratamento irrigado por pivô central e de 0,15 a 1,15 no tratamento irrigado por gotejamento. A média dos valores de Kc no 2º, 3º e 4º ano durante os períodos vegetativos e produtivos foi de 0,77, 0,93 e 0,82 no tratamento irrigado por pivô central, respectivamente, e 0,69, 0,79 e 0,74 no tratamento irrigado por gotejamento, respectivamente. A relação entre Kc e IAF mostrou, para o tratamento irrigado por pivô central, um ajuste logaritmo com coeficiente de determinação (R2) e somatória do erro médio ao quadrado (SEMQ) de 0,7643 e 0,334, respectivamente, e 0,8443 e 0,2079 para o tratamento irrigado por gotejamento, respectivamente. Nos três anos analisados, Kc correlacionado com SUT mostrou o melhor ajuste à equação polinomial de 2ª ordem para os dois tratamentos.
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Stephan, Karl Eckart [Verfasser], Manfred [Gutachter] Frühauf, and Carsten [Gutachter] Lorz. "Standörtliche Wasserhaushaltsgrößen in der südsibirischen Kulunda-Steppe : vergleichende Erhebung und Prüfung von Messdaten aus Lysimeter- und Feldversuchen / Eckart Stephan ; Gutachter: Manfred Frühauf, Carsten Lorz." Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2020. http://d-nb.info/1220698202/34.
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Kim, Minseok, Luke A. Pangle, Charléne Cardoso, Marco Lora, Till H. M. Volkmann, Yadi Wang, Ciaran J. Harman, and Peter A. Troch. "Transit time distributions and StorAge Selection functions in a sloping soil lysimeter with time-varying flow paths: Direct observation of internal and external transport variability." AMER GEOPHYSICAL UNION, 2016. http://hdl.handle.net/10150/622147.
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Transit times through hydrologic systems vary in time, but the nature of that variability is not well understood. Transit times variability was investigated in a 1 m(3) sloping lysimeter, representing a simplified model of a hillslope receiving periodic rainfall events for 28 days. Tracer tests were conducted using an experimental protocol that allows time-variable transit time distributions (TTDs) to be calculated from data. Observed TTDs varied with the storage state of the system, and the history of inflows and outflows. We propose that the observed time variability of the TTDs can be decomposed into two parts: internal variability associated with changes in the arrangement of, and partitioning between, flow pathways; and external variability driven by fluctuations in the flow rate along all flow pathways. These concepts can be defined quantitatively in terms of rank StorAge Selection (rSAS) functions, which is a theory describing lumped transport dynamics. Internal variability is associated with temporal variability in the rSAS function, while external is not. The rSAS function variability was characterized by an inverse storage effect, whereby younger water is released in greater proportion under wetter conditions than drier. We hypothesize that this effect is caused by the rapid mobilization of water in the unsaturated zone by the rising water table. Common approximations used to model transport dynamics that neglect internal variability were unable to reproduce the observed breakthrough curves accurately. This suggests that internal variability can play an important role in hydrologic transport dynamics, with implications for field data interpretation and modeling.
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GonÃalves, Fabricio Mota. "EvapotranspiraÃÃo e coeficientes de cultivo (KC) da cana-de-aÃÃcar irrigada por gotejamento subsuperficial." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5272.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoSugar cane is one of the crops with the highest level of water consumption, with a high evapotranspiration demand throughout most of its cycle. Knowledge of the sugar cane water demand, the time that irrigation should be applied, and how to irrigate the crop are becoming increasingly important for the sustainable development of irrigated sugar cane cultivation, especially in areas of low water availability, as it is the case in northea stern Brazil. The experiment was carried out at the Curu Experimental Field (property of the Embrapa Tropical Agroindustry), located in the Curu-Paraipaba Irrig ation Project, city of Paraipaba-CE (3 Â 29 '20''S, 39 Â 9' 45''W and elevation 30m), in order to determine the evapotrans piration and crop coefficients (Kc) of sugarcane (Saccharum L. officinarium), subsurface drip-irrigated. It was used the SP 6949 sugar cane variety, planted in a spacing of 1.8 m between double rows and 0.4 m between rows within the double row. As to t he irrigation, we used one lateral water line for each double row, buried at a depth of 0.15 m, w ith self-compensating drip emitters, with a flow rate of 1 L h-1, spaced 0.5 m on the water line. The crop was irrigated daily and there were three fertigations per week. The irrigation de pth was periodically adjusted, keeping the soil water potential between -8 kPa to -20 kPa. The crop evapotranspiration (ETc) was determined using a wei ghing lysimeter with a surface area of 2.25 m 2. The reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method. The durations of the phenological stages of cane sugar were estimated through analysis of soil cover, with the use of digital images. Durations of 31, 49, 237 and 118 days were observed, respectively for initial, crop development, mid-season and late season stages. The yields achieved within and outside the lysimeter were respectively 144.4 and 108.8 t ha -1 . The total ETc observed during the cycle of the sugar cane was 1074.1 m m, with maximum values of 6.6 mm d-1 during the mid-season stage. Observed Kc values for initial, mid-season and late season stages were respectively 0.23, 1 .03 and 0.50. In the crop development stage, the relationship between Kc and the (crop) soil cover was represented with good accuracy by a negative quadratic model.
A cana-de-aÃÃcar à uma das culturas com maior consumo de Ãgua, apresentando uma alta demanda evapotranspirativa ao longo da maior parte do seu ciclo. O conhecimento das necessidades hÃdricas da cana-de-aÃÃcar, do momento de aplicaÃÃo da Ãgua requerida pela mesma e a forma de aplicaÃÃo torna-se cada vez mais importante para o desenvolvimento sustentÃvel da sua produÃÃo irrigada, principalmente em regiÃes de pouca disponibilidade hÃdrica, como à o caso da regiÃo Nordeste do Brasil. O experimento foi conduzido no Campo Experimental do Curu, pertencente à Embrapa AgroindÃstria Tropical localizado no PerÃmetro Irrigado Curu-Paraipaba, municÃpio de Paraipaba-CE (3 29â 20ââ S, 39 9â 45ââ W e altitude de 30 m), com o objetivo de determinar a evapotranspiraÃÃo e os coeficientes de cultivo (Kc) da cana-de-aÃÃcar (Saccharum officinarium L.), irrigada por gotejamento subsuperficial. Utilizou-se a variedade de cana SP 6949, plantada no espaÃamento de 1,8 m entre fileiras duplas e 0,4 m entre linhas dentro da fileira dupla. Na irrigaÃÃo utilizou-se uma linha lateral para cada fileira dupla, enterrada na profundidade de 0,15 m, com gotejadores autocompensantes, com vazÃo de 1 L h-1, espaÃados de 0,5 m na linha. A cultura foi irrigada com freqÃÃncia diÃria e foram realizadas trÃs fertirrigaÃÃes por semana. A lÃmina de irrigaÃÃo foi ajustada periodicamente, mantendo-se o potencial de Ãgua no solo entre -8 kPa e -20 kPa. A evapotranspiraÃÃo da cultura (ETc) foi determinada utilizando-se um lisÃmetro de pesagem com Ãrea superficial de 2,25 m2. A evapotranspiraÃÃo de referÃncia (ETo) foi estimada pelo mÃtodo FAO Penman-Monteith. As duraÃÃes das fases fenolÃgicas da cana-de-aÃÃcar foram estimadas por meio da anÃlise da cobertura do solo pela cultura, determinada com o uso de imagens digitais. Foram observadas duraÃÃes de 31, 49, 237 e 118 dias, para as fases inicial, de desenvolvimento, intermediÃria e final, respectivamente. A produtividade alcanÃada dentro e fora do lisÃmetro foi de 144,4 e 108,8 t ha-1, respectivamente. A ETc total observada durante o ciclo da cana-de-aÃÃcar foi de 1.074,1 mm, com valores mÃximos da ordem de 6,6 mm d-1 durante a fase intermediÃria. Foram observados valores de Kc iguais a 0,23, 1,03 e 0,50, para as fases inicial, intermediÃria e final, respectivamente. Na fase de desenvolvimento vegetativo a relaÃÃo entre o Kc e a cobertura do solo pela cultura foi representada com bastante exatidÃo por um modelo quadrÃtico negativo.
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Santiago, Alailson Venceslau. "Evapotranspiração de referência medida por lisímero de pesagem e estimada por Penman-Monteith (FAO-56), nas escalas mensal e decendial." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11131/tde-16052002-095603/.
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A evapotranspiração de referência (ETo, mm d-1) foi medida por um lisímetro de pesagem acoplado a três células de carga, durante 1996, em Piracicaba, SP. Discute-se as dificuldades operacionais encontradas com esse tipo de lisímetro em dias com chuvas intensas e em seqüência de dias com chuvas intermitentes. A série temporal dos valores medidos diariamente foi agrupada em seqüências de 10 ou 30 dias, gerando conjuntos de valores médios representativos dessas duas escalas de tempo. Média móvel com diversos passos foram usadas para aumentar o número de pontos nos conjuntos gerados e para verificar seus efeitos sobre as relações estatísticas. Estimativas de ETo médio correspondentes aos intervalos de tempo das médias medidas foram obtidas com a equação de Penman-Monteith seguindo-se as parametrizações e procedimentos descritos no boletim FAO-56, usando dados meteorológicos de uma estação automatizada situada próxima ao lisímetro. A análise de regressão linear simples (Lisímetro = b Estimativa) mostrou as seguintes tendências estatística: 1) na escala de 30 dias, Y = 1,0905 X ± 0,212 mm d-1, r2 = 0,9512 de janeiro a junho; e Y = 0,9622 X ± 0,166 mm d-1, r2 = 0,8249 de agosto a novembro; 2) na escala de 10 dias, Y = 1,0866 X ± 0,332 mm d-1, r2 = 0,9158 de janeiro a junho; e Y =0,9573 X ± 0,323 mm d-1, r2 = 0,7729 de agosto a novembro. Os diferentes passos não afetaram substancialmente o valor de b; mas, em geral, o erro médio da estimativa aumentou quando o passo aumentou, diminuindo o número de pontos comparados. Face às dificuldades de medir ETo em períodos chuvosos as relações obtidas no segundo período talvez expressem melhor o grau de ajuste das estimativas. A performance das estimativas não se alterou quando se substituiu o saldo de radiação medido por valor estimado usando os procedimentos FAO-56, simulando uma situação muito comum de ausência de medida desse elemento meteorológico.Reference evapotranspiration (ETo, mm d-1) was measured by a weighing lysimeter coupled with three load cells, during 1996, in Piracicaba, SP, Brazil. Operational difficulties with this kind of lysimeter during days with high intensity rainfall and also during a sequence of days with intermittent rains are discussed. The time series of measured ETo was pooled in sequences of either 10 or 30 days generating groups of mean values for such time scales. Moving averages with different steps were used to increase the number of points in each group and to test their effect upon the statistical relationships. Estimatives of mean ETo corresponding to the time intervals of the measured averages were computed with the Penman-Monteith equation following the parameterizations and procedures described in the FAO Irrigation and Drainage Paper 56, using data given by an automatic meteorological weather station located next to the lysimeter. Simple linear regression analysis (Lysimeter = b Estimative) indicates the following statistical tendencies: 1) for the 30-days time scale, Y = 1.0905 X ± 0.212 mm d-1, r2 = 0.9512 from january to june; and Y = 0.9622 X ± 0.166 mm d-1, r2 = 0.8249 from august to november; 2) for the 10-days time scale, Y = 1.0866 X ± 0.332 mm d-1, r2= 0.9158 from january to june; e Y = 0.9573 X ± 0.323 mm d-1, r2 = 0.7729 from august to november. The different time steps did not affect substantially the b value; but, in general, as the time step increased so did the mean error of the estimative due to the decrease in the number of points compared. Due to the operational difficulties in measuring ETo during periods of high intensity rains perhaps the relationships found for the second period represents better the degree of fit of the estimatives. The performance of the ETo estimatives did not change substantially when the measured net radiation was substituted by an estimative using the FAO-56 guidelines, simulating a very common situation of lack of such weather element.
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Silva, Tonny José Araújo da. "Evapotranspiração e coeficiente de cultivo de maracujazeiros determinados pelo método do balanço de radiação e lisimetria de pesagem hidráulica." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-15072005-152748/.
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Este trabalho foi realizado na área experimental de irrigação, na Fazenda Areão do Departamento de Engenharia Rural da Escola Superior de Agricultura Luiz de Queiroz - ESALQ/USP (Piracicaba-SP). Transplantaram-se mudas de maracujazeiro amarelo (Passiflora edulis Sims f. flavicarpa Deg), cv. IAC 275, com 83 dias após a germinação, para duas parcelas experimentais com espaldeiras na direção Norte-Sul e Leste-Oeste. O método da razão de Bowen foi utilizado na determinação dos fluxos de calor sensível e latente. Foram coletados dados de saldo de radiação, fluxo de calor no solo, gradientes de temperatura e pressão de vapor com objetivo de avaliar a partição da energia disponível e a evapotranspiração em cultivo de maracujazeiros. Em teste de laboratório e campo, avaliaou-se o desempenho das células de carga hidráulica, através de calibrações simultâneas em comparação as células eletrônicas, e por fim, verificou-se o funcionamento de um transdutor de pressão eletrônico acoplado às células para automação dos dados. Na determinação do consumo de água pelas plantas, utilizaram-se quatro lisímetros de pesagem hidráulica, iguais, sendo dois por parcela. Nos lisímetros de pesagem hidráulica o consumo medido, em litros planta-1 dia-1, foi ajustado de acordo com a área foliar da planta instalada, para hipoteticamente uniformizar o desenvolvimento vegetativo, permitindo assim, compará-las entre si. O saldo de radiação não foi influenciado pelo sistema de plantio, sendo equivalente a 60% da radiação global. O componente de maior contribuição no balanço de radiação foi o calor latente de evaporação. O fluxo de calor sensível teve valores mais significativos imediatamente após as chuvas ou irrigações. A utilização do modelo de análise e exclusão de intervalos em que o método de Razão de Bowen falha, melhora a estimativa da evapotranspiração. O arranjo das células de carga em forma de triangulo eqüilátero promoveu boa estabilidade e distribuição equilibrada de forças. O estabelecimento do volume ideal de fluído proporcionou calibrações lineares e consequentemente, melhor desempenho dos lisímetros. As correlações entre os valores de variação de massa observadas no piezômetro, célula eletrônica e transdutor de pressão apresentaram relação linear com alto coeficiente de determinação. A lâmina acumulada até o 450 DAP representativa para a parcela Norte-Sul foi de 1171 mm, superior a 1083 mm acumulado na parcela Leste-Oeste. Os valores extremos de consumo foram em média 5 L planta-1 dia-1, durante o outono e inverno, e 8 L planta-1 dia-1, no Verão. Não houve diferença significativa para a ETc das parcelas nos meses de menor disponibilidade energética. Foram determinados coeficientes de cultivo de 0,6 para a fase de crescimento vegetativo apical, 0,9 para a fase de crescimento vegetativo lateral, 1,2 para a fase de floração e frutificação, 1,0 para a fase de maturação dos frutos, 0,8 para a fase pósmaturação dos frutos.This work was carried out at the experimental irrigation farm of the Engineering Department - College of Agriculture Luiz de Queiroz - ESALQ/USP in Piracicaba, São Paulo, State. The 83-day-old passiflora seedlings (Passiflora edulis Sims f. flavicarpa Deg cv. IAC 275) were transplanted to experimental units with rows planted based on North- South and East-West directions. The Bowen ratio method was used to determine both sensible heat and latent heat fluxes. It was collected micrometeorological data from net radiation, soil flux heat, temperature and vapor pressure gradient with the aim to evaluate the energy available partition and evapotranspiration of trees planted under two row directions. The performance of a hydraulic load cells and a pressure transductor were evaluated by calibration of electronic load cells in laboratory and field conditions. In order to determine the evapotranspiration, it was used four similar hydraulic weighing lysimeters, being two in each direction of plant row. The daily evapotranspiration in liters per plant was adjusted to the leaf area present in each lysimeter, to hypothetically uniform the vegetative development and compare the values themselves. The net radiation was not influenced by row directions, and it was 60% of global radiation. The latent heat of evaporation was the major role on energy balance and the significant values happened immediately after a rainfall or irrigation. The use of intervals and exclusion analyzes model, when the Bowen ratio fails, improve the estimative of evapotranspiration. The triangular design of load cells promoted a good stability and distribution of forces. The establishment of an ideal fluid volume leaded a liner calibrations and better performances. Relationships between mass variation read in piezometer, electronic load cells and pressure transductor showed linear relation and high determination coefficient. The accumulative depth at 450 DAP for North-South unit was 1171 mm higher than 1083 mm for East-West. The average of extremes values for evapotranspiration was 5 L plant-1 day-1 for autumn and winter and 8 L plant-1 day-1 for summer period. No significant differences were found for ETc for units in months of lower energetic availability. The values for crop coefficient were 0.6 for apex vegetative growth, 0.9 for lateral vegetative growth, 1.2 for flowering and fruit development, 1.0 for fruit maturation and 0.8 for post-maturation period.
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Zanuzo, Lusiani. "Comportamento de cátions percolados oriundos da aplicação de água residuária de suinocultura em solo cultivado com milho." Universidade Estadual do Oeste do Parana, 2007. http://tede.unioeste.br:8080/tede/handle/tede/232.
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Previous issue date: 2007-07-19The objective of this work was evaluated the cation´s leaching corn planted and irrigated with swine waste water in lysimeters. The factors and levels of treatments were: four levels of with swine wastewater (112.5, 225.0, 337.5 and 450.0 m3 ha-1), two levels of chemical fertilization (50% and 75% of nitrogen recommend) and three repetitions. The time after sowing was considered analysis factor to evaluate the time effects accumulation of cations in soil. The irrigation was realized switching water and wastewater in each period of 15 days. The lysimeters was built with fiber boxes, capacity of 1 m3, 1.6 m of diameter, spacing of 0,4 x 0,5 m and 1,2 m of depth. The statistical analysis used was split-plot. The leaching´s concentrations were larger for the chemical elements in the following order: Na+ > K+ > Ca2+ > Mg2+. In general, the factor swine wastewater produced proportional larger concentrations in the leaching of Na+. The chemical fertilization factor influenced in the largest concentrations of the K+ leaching. The time after sowing influenced in the largest concentrations of Ca2+ and Mg2+ in the soil and of Na+ leaching.
O objetivo deste trabalho foi avaliar os cátions lixiviados em lisímetros preenchidos com solo tipo Latossolo Vermelho Distroférrico, cultivados com milho irrigado com água residuária de suinocultura. Os fatores estudados foram a água residuária em quatro níveis (112,5, 225,0, 337,5 e 450 m3/ha) e a adubação química em dois níveis (50% e 75% do nitrogênio recomendado para a cultura do milho) ao longo do ciclo da cultura. A irrigação foi realizada intercalando água e água residuária de suinocultura a cada 15 dias. Os cátions avaliados no solo e no percolado foram K+, Na+, Ca2+, Mg2+. O delineamento experimental foi em esquema fatorial 4x2, com três repetições por tratamento e avaliações em quatro períodos do desenvolvimento da planta. As médias foram comparadas pelo teste de Tukey a 5% de significância. Os resultados apontam que as concentrações médias dos lixiviados foram maiores para os elementos químicos estudados na seguinte ordem: Na+> K+ > Ca2+ >Mg2+. As taxas da água residuária de suinocultura produziram, proporcionalmente, maiores concentrações médias nos lixiviados para Na+, apenas no último período avaliado. A adubação química influenciou nas maiores concentrações do K+ lixiviado. De modo geral, ao longo do experimento, foram observadas maiores concentrações de Ca2+ e Mg2+ no solo e de Na+ no lixiviado.
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Ferreira, José Orlando Piauilino. "Evapotranspiração e coeficientes de cultura da melancieira irrigada por gotejamento em Alvorada do Gurguéia-PI /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/105227.
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Resumo: Este experimento foi conduzido em Alvorada do Gurguéia, situada no vale do rio Gurguéia, estado do Piauí, localizado na latitude de 8º 26' S, longitude 43º 47' W e altitude de 251 m. Os objetivos deste estudo foram determinar a evapotranspiração (ETc) e os coeficientes de cultura (Kc) da melancieira irrigada por gotejamento. A evapotranspiração de referência (ETo) foi determinada diariamente por dez modelos de estimativa, com parte dos elementos climáticos obtidos em uma estação agrometeorológica automática localizada no centro da área experimental. Os modelos foram: Penman-Monteith-FAO56 (PMFAO56), Penman-Monteith-ASCE (PMASCE), Hargreaves-Samani (HS), Priestley-Taylor (PT), Camargo (CAM), Thornthwaite original (THW), Thornthwaite com correção para a temperatura efetiva calculada como uma função da temperatura média e da amplitude diária e valores de K=0,69 (THW2(0,69)) e K=0,72 (THW3(0,72)) e Thornthwaite com a mesma temperatura efetiva corrigida para o fotoperíodo e valores de K=0,69 (THW2(0,69)) e K=0,72 (THW2(0,72)). A ETc foi medida a partir de três lisímetros de pesagem localizados no centro da área experimental. O desempenho dos métodos foi avaliado utilizando regressão linear simples e diferentes índices: raiz quadrada do erro médio quadrático (RMES), erro percentual absoluto médio (MAPE), índice de concordância (d) e o teste de Scott-Knott, usando como padrão EToPMFAO56. O modelo PMASCE foi semelhante ao PMFAO56, com RMES = 0,05 mm dia-1, MAPE = 0,74%, d = 1,0 e R2 = 0,99. Apenas os modelos, THW2(0,69) e THW3(0,72), não apresentaram médias gerais significativamente diferentes de PMFAO56. Os valores médios de Kc obtidos com o PMFAO56 foram 0,44; 1,58 e 1,28 para os estádios inicial, intermediário e final, respectivamente. Valores estes, assim como os de todos os demais métodos de estimativa de ET0 testados, foram superiores aos obtidos... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: This experiment was carried out at the Gurguéia river valley, state of Piauí, Brazil, located at 8º 26' S latitude, 43º 47' W longitude an altitude of 251 m. The objectives of this study were to determine the evapotranspiration (ETc) and crop coefficients (Kc) of watermelon by drip irrigated. Reference evapotranspiration (ETo) was daily determined by ten models of the estimation, with part climatics variable obtained an automatic agrometeorological station located in the center of the experimental area. The models were: Penman-Monteith-FAO56 (PMFAO56), Penman- Monteith-ASCE (PMASCE), Hargreaves-Samani (HS), Priestley-Taylor (PT), Camargo (CAM), original Thornthwaite (THW), Thornthwaite with correction for effective temperature computed as a function of the average temperature and of the daily amplitude and values of K=0,69 (THW2(0,69)) and K=0,72 (THW3(0,72)) and Thornthwaite with the same effective temperature corrected for the photoperiod and value of K=0,69 (THW2(0,69)) and K=0,72 (THW3(0,72)). ETc was measured from three weighing lysimeters located in the center of the experimental area. Methods performance was evaluated by using single linear regression and different indices, root mean square error (RMES), mean absolute percentage error (MAPE), index of agreement (d) and Scott-Knott test, using how standard PMFAO56. The model PMASCE was resembling to PMFAO56, with RMES = 0,05 mm dia-1, MAPE = 0,74%, d = 1,0 and R² = 0,99. Only the models, THW2(0,69) e THW3(0,72), not presents generals average significant difference of the PMFAO56. The Kc values obtained were 0,44, 1,58 and 1,28 for the initial, intermediate and final stages, respectively. This values, thus as of the every methods of estimation of the ETo tested, was upper to obtained for watermelon in the Bulletin 56 of irrigation and drainage of the FAO, principally for the intermediate and final stages... (Complete abstract click electronic access below)
Orientador: Luiz Carlos Pavani
Coorientador: Edson Alves Bastos
Banca: Aderson Soares de Andrade Junior
Banca: Regina Célia de Matos Pires
Banca: Jose Renato Zanini
Banca: Mario Benincasa
Doutor
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Ferreira, José Orlando Piauilino [UNESP]. "Evapotranspiração e coeficientes de cultura da melancieira irrigada por gotejamento em Alvorada do Gurguéia-PI." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/105227.
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Este experimento foi conduzido em Alvorada do Gurguéia, situada no vale do rio Gurguéia, estado do Piauí, localizado na latitude de 8º 26’ S, longitude 43º 47’ W e altitude de 251 m. Os objetivos deste estudo foram determinar a evapotranspiração (ETc) e os coeficientes de cultura (Kc) da melancieira irrigada por gotejamento. A evapotranspiração de referência (ETo) foi determinada diariamente por dez modelos de estimativa, com parte dos elementos climáticos obtidos em uma estação agrometeorológica automática localizada no centro da área experimental. Os modelos foram: Penman-Monteith-FAO56 (PMFAO56), Penman-Monteith-ASCE (PMASCE), Hargreaves-Samani (HS), Priestley-Taylor (PT), Camargo (CAM), Thornthwaite original (THW), Thornthwaite com correção para a temperatura efetiva calculada como uma função da temperatura média e da amplitude diária e valores de K=0,69 (THW2(0,69)) e K=0,72 (THW3(0,72)) e Thornthwaite com a mesma temperatura efetiva corrigida para o fotoperíodo e valores de K=0,69 (THW2(0,69)) e K=0,72 (THW2(0,72)). A ETc foi medida a partir de três lisímetros de pesagem localizados no centro da área experimental. O desempenho dos métodos foi avaliado utilizando regressão linear simples e diferentes índices: raiz quadrada do erro médio quadrático (RMES), erro percentual absoluto médio (MAPE), índice de concordância (d) e o teste de Scott-Knott, usando como padrão EToPMFAO56. O modelo PMASCE foi semelhante ao PMFAO56, com RMES = 0,05 mm dia-1, MAPE = 0,74%, d = 1,0 e R2 = 0,99. Apenas os modelos, THW2(0,69) e THW3(0,72), não apresentaram médias gerais significativamente diferentes de PMFAO56. Os valores médios de Kc obtidos com o PMFAO56 foram 0,44; 1,58 e 1,28 para os estádios inicial, intermediário e final, respectivamente. Valores estes, assim como os de todos os demais métodos de estimativa de ET0 testados, foram superiores aos obtidos...
This experiment was carried out at the Gurguéia river valley, state of Piauí, Brazil, located at 8º 26’ S latitude, 43º 47’ W longitude an altitude of 251 m. The objectives of this study were to determine the evapotranspiration (ETc) and crop coefficients (Kc) of watermelon by drip irrigated. Reference evapotranspiration (ETo) was daily determined by ten models of the estimation, with part climatics variable obtained an automatic agrometeorological station located in the center of the experimental area. The models were: Penman-Monteith-FAO56 (PMFAO56), Penman- Monteith-ASCE (PMASCE), Hargreaves-Samani (HS), Priestley-Taylor (PT), Camargo (CAM), original Thornthwaite (THW), Thornthwaite with correction for effective temperature computed as a function of the average temperature and of the daily amplitude and values of K=0,69 (THW2(0,69)) and K=0,72 (THW3(0,72)) and Thornthwaite with the same effective temperature corrected for the photoperiod and value of K=0,69 (THW2(0,69)) and K=0,72 (THW3(0,72)). ETc was measured from three weighing lysimeters located in the center of the experimental area. Methods performance was evaluated by using single linear regression and different indices, root mean square error (RMES), mean absolute percentage error (MAPE), index of agreement (d) and Scott-Knott test, using how standard PMFAO56. The model PMASCE was resembling to PMFAO56, with RMES = 0,05 mm dia-1, MAPE = 0,74%, d = 1,0 and R² = 0,99. Only the models, THW2(0,69) e THW3(0,72), not presents generals average significant difference of the PMFAO56. The Kc values obtained were 0,44, 1,58 and 1,28 for the initial, intermediate and final stages, respectively. This values, thus as of the every methods of estimation of the ETo tested, was upper to obtained for watermelon in the Bulletin 56 of irrigation and drainage of the FAO, principally for the intermediate and final stages... (Complete abstract click electronic access below)
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Silva, Eduardo Magno Pereira da. "DeterminaÃÃo do coeficiente de cultura da melancia, em solo sob palhada e preparo convencional, na microrregiÃo de Teresina, PiauÃ." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7966.
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Arantes, Kelte Resende. "Desenvolvimento de mudas de cafeeiro cultivadas em tubetes e submetidas a diferentes níveis de déficit hídrico." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-14092007-143001/.
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A cafeicultura é uma atividade de grande importância no cenário sócio-econômico do Brasil, movimentando bilhões de dólares todos os anos e gerando milhares de empregos diretos e indiretos. O sucesso no cultivo de lavouras cafeeiras depende da observação de diversos cuidados, dentre os quais, a escolha de mudas com bom potencial genético, sadias e vigorosas. A utilização de sacos de polietileno como recipiente para o substrato na produção de mudas de cafeeiro apesar de tradicional, vêm perdendo espaço para os tubetes de polietileno rígido. Apesar das vantagens que os tubetes apresentam, como possibilidade de mecanização do enchimento e plantio, reutilização dos recipientes e menor quantidade de mão-de-obra utilizada, estes necessitam de substrato com características diferenciadas. Devido a isto, na produção de mudas em tubetes é necessária a utilização de um método de irrigação de alta eficiência, assim como de um manejo adequado para este. Há relatos na literatura atual mostrando a inadequação dos métodos de irrigação, empregados na produção de mudas de cafeeiro em tubetes. A utilização de uma irrigação inadequada pode gerar problemas no desenvolvimento da cultura, seja por deficiência hídrica, umidade excessiva do meio de crescimento, ou por propiciar o aparecimento e propagação de doenças relacionadas. Frente a esta necessidade, pretendeu-se com este trabalho gerar informações que orientem os produtores no manejo adequado da subirrigação na produção de mudas de cafeeiro em tubetes, determinando as implicações envolvidas na utilização deste método. O experimento foi conduzido em uma casa de vegetação na área experimental do Setor de Irrigação e Drenagem do Departamento de Engenharia Rural da Escola Superior de Agricultura "Luiz de Queiroz" - ESALQ/USP, no município de Piracicaba-SP. As mudas utilizadas no experimento foram de cafeeiros da cultivar Catuaí Vermelho, variedade LCH-2077- 2-5-99. O método de irrigação utilizado foi por subirrigação. O controle da irrigação foi realizado a partir da variação de peso dos tubetes com as mudas, devido a perda de água por evapotranspiração. No processo de controle dos pesos foram utilizadas células de carga, que monitoraram a variação de peso de um conjunto de tubetes denominado conjunto controle. O delineamento experimental foi em Blocos aleatorizados com quatro repetições. Os tratamentos avaliados foram cinco níveis de depleção da máxima capacidade de retenção de água (MCRA) apresentada pelo substrato (15%, 30%, 45%, 60% e 75% da MCRA). As parcelas foram constituídas por 32 tubetes. Para se quantificar os efeitos dos tratamentos foram avaliados mensalmente as seguintes características das mudas: Altura do ramo ortotrópico, diâmetro do ramo ortotrópico, área foliar, bem como os valores de matéria seca da parte aérea e do sistema radicular. A subirrigação manejada por lisimetria foi considerado tecnicamente viável, para produção de mudas de cafeeiro em tubetes. O sistema automático de manejo da irrigação, se mostrou adequado para monitorar e controlar a irrigação. Os níveis de depleção acima de 45% se mostraram limitantes ao desenvolvimento das mudas, sendo nível de depleção de 27% considerado ideal.Coffee production is a very important activity in the socioeconomic context in Brazil, which makes billion of dollars go around the economy every year generating thousands of direct and indirect jobs. The success in the coffee production depends on the observation of several needs, among others the choice of healthy and vigorous seedlings with good genetic potential. The use of sacks of polyethylene as a container for the substrate in the production of coffee seedlings is traditional, nevertheless are losing space for the plastic tubes. Despite some advantages of plastic tubes like the possibility of mechanization of filling and planting, the reuse of the containers and the smaller number of employees demanded in the production, the plastic tubes need substrate with special characteristics. In the production of coffee seedlings in plastic tubes is necessary the use of irrigation of high efficiency, as well as appropriate manipulation. There are reports in the literature showing a lack of suitability of the irrigation methods in the production of coffee seedlings in plastic tubes. The use of inadequate irrigation methods can cause problems in the culture development, due to hydric deficiency, excessive moisture, or for fostering the appearance and propagation of diseases. On the basis of these aspects, the objective of this work was to generate information to guide the producers in an appropriate handling of the sub-irrigation in the coffee seedling production in plastic tubes, determining the involved implications in the use of that method. The experiment was carried out in a greenhouse in an experimental area of the Irrigation and Drainage Section of the Rural Engineering Department of the Superior School of Agriculture "Luiz de Queiroz" – ESALQ/USP, in the city of Piracicaba, São Paulo State. The seedlings used in the experiment were coffee plants of the species Coffea arabica cv. Catuaí Vermelho, variety LCH-2077-2-5-99. The irrigation method used was by subirrigation. The irrigation control was done according to the weight variation of the plastic tubes with the seedlings, due to the loss of water by evapotranspiration. In the control process of the weights were used load cells, which monitored the weight variation of a group of plastic tubes, denominated control group. The experimental design was in randomized blocks with four replications. The evaluated treatments had five levels of depletion of the maximum capacity of water retention (MCRA) presented by the substrate (15%, 30%, 45%, 60% and 75% of the MCRA). The plots were constituted of 32 plastic tubes. To quantify the effects of the treatments were monthly measured the following characteristics of the seedlings: Height of the orthopic brach, diameter of the orthopic branch, leaf area, as well as the values of dry matter of the aerial part and radicular system. The handling of sub-irrigation by lysimeter was technically viable for the production of coffee seedlings in plastic tubes. The automatic system for handling the irrigation was adequate to monitor and control it. The levels of depletion above 45% limited the development of seedlings, however the depletion of 27% was considered ideal.
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Amorim, Marcelo Cid de. "Avaliação da eficácia do lisímetro de lençol freático constante, do tanque classe A e do modelo de Penmam-Monteith (FAO) para estimativa da evapotranspiração de referência (ETo)." Universidade Federal de Viçosa, 1997. http://locus.ufv.br/handle/123456789/5269.
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Previous issue date: 1997-10-07Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A field research work was carried out to evaluate the FAO Penman- Monteith method, the constant watertable lysimeter and the Class A pan for estimating the reference evapotranspiration (ETo) as a function of the main climatic data (air temperature, relative humidity, wind speed and sunshine duration) obtained in a conventional meteorological station at Governador Dix- Sept Rosado county. A model for determining the class A pan coefficient (Kt) was also proposed for that location. The regression and path analysis were used in evaluating the direct and indirect effects from each collected climatic elements on estimated ETo rates. ln both analyses the reference evapotranspiration was the dependent variable (Y) and the climate elements were the independent variables (X). According to the results, the Penman- Monteith method showed a better adequacy in estimating the ETo rates from the climatic elements data either for dally values or flve days averaged values. For the five days averaged values the evapotranspiration measuring equipment showed a substantial improvement in the coefñcient of determination. The regression and path analysis showed similar results emphasizing that the sunshine duration is the main clímatic element in the evapotranspiration process either as direct or indirect effect. lt was observed that the Kt values for the study area was only 0.73. thus much |ess then 0.85 determined by FAO.
Este estudo teve como objetivo avaliar o método de Penman-Monteith (FAO). o lisímetro de lençol freático constante e o evaporímetro tanque Classe "A" na estimativa da evapotranspiração de referência (ETo), em função dos principais dados climáticos disponíveis (temperatura do ar à sombra, umidade relativa, velocidade do vento e número de horas de brilho solar) na estação meteorológica principal, instalada no município de Governador Dix-Sept Rosado. Foi proposto também um modelo para determinar o coeficiente de tanque (Kt) para o tanque Classe A". Para avaliar os efeitos direto e indireto de cada elemento climático na estimativas da ETo obtidas pelos diferentes métodos utilizou-se a análise de regressão e de trilha. Em ambas as análises a evapotranspiração de referência foi a variável dependente (Y) e os elementos climáticos as variáveis independentes (X). As variáveis estudadas foram provenientes de dados diários e médias de períodos de cinco dias. De acordo com os resultados, o método de Penman-Monteith (FAO) apresentou melhor coeficiente de correlação na análise de regressão quadrática com os elementos do clima, tanto para valores diários quanto para valores médios de cinco dias. Para os valores médios de cinco dias, os dados apresentaram substancial melhoria no coeficiente de determinação com os valores de ETo medidos pelos equipamentos. Pela análise regressão e de trilha os resultados foram semelhantes, comprovando que a duração do brilho solar diário é o principal elemento do clima no processo da evapotranspiração de referência, tanto como efeito direto quanto indireto. Observou-se que o Kt proposto para a região em estudo teve um coeficiente máximo de 0.73. muito inferior, portanto, ao valor recomendado pela FAO de 0,85.
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SANTOS, Francisco Xavier dos. "Lisímetro de pesagem hidráulica e evapotranspiração de referência por diferentes métodos no agreste pernambucano." Universidade Federal Rural de Pernambuco, 2004. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5314.
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The aim of this work was to build and test the functioning of an hydraulic weighing lysimeter with a mercury piston arranjement, and to relate the reference evapotranspiration (ETo) determined by the lysimeter with that estimated by agrometeorological models and by evaporimetric pans. The reseach was conducted at the Nossa Senhora do Rosário Farm, in Pesqueira, Pernambuco State, Brazil, where the lysimeter is located under the coordinates 08°10’25” South latitude and 35°11’25” west latitude and at an altitude of 613 m. The local climate is of the BS’s’h type acording to Koppen. The meteorological elements data and the evaporation were obtained from an automatic agrometeorological station (Campbell Scientific ET106), from a Class A pan and from an experimental pan. The following models were used: Blaney-Criddle, Camargo, Hargreaves-Samani, Jensen-Haise, Makkink, Penmam-1963, Penmam-FAO, Penmam-Monteith, Radiação-FAO e Thorntwaite-Camargo. The lysimeter tank had a volume capacity of 2.059 m3 and a surface area of 2.068 m2, planted with pangola grass (Digitaria decumbens Stent.). The preliminary calibrations tests, using up to 50 mm water depth, with progressive witshowed excellent responses throughout the testing. The range ysimeter operated with a final field precision of 0.143 mm, corresponding to a volume of 14 dm3. The lysimeter estability was high, where the greatest positional average error measured at 3.93%. The lysimeter’s performance acording to Willmott’s index, using Penman-Monteith method as a standard, was “Very bad” for measurements on a daily scale and “Bad” with tridial dates, reveling a strong local advective effect upon evapotranspiration. The same effect was evidenced upon the readings of the evaporation pans, which also showed unsactisfactory performance in relationship to the standard method.
O objetivo deste trabalho foi a construção e testar o funcionamento de um lisímetro de pesagem hidráulica com arranjo de pistão de mercúrio, e relacionar a evapotranspiração de referência (ETo) determinada pelo lisímetro com aquela estimada por modelos agrometeorológicos e por tanques de evaporação. A pesquisa foi conduzida na Fazenda Nossa Senhora do Rosário, Pesqueira – PE, na qual o lisímetro está instalado sob as coordenadas 08º10´25 de latidude Sul e 35º11´25 de longitude Oeste e 613 m de altitude. O clima local é do tipo BSs’h’ segundo Koppen. Os dados dos elementos meteorológicos e de evaporação foram obtidos de uma estação agrometeorológica automática (Campbell Scientific ET106), de um Tanque Classe A e de um Tanque Experimental. Foram usadas as seguintes equações: Blaney-Criddle, Camargo, Hargreaves-Samani, Jensen-Haise, Makkink, Penmam-1963, Penmam-FAO, Penmam-Monteith, Radiação-FAO e Thorntwaite-Camargo. O lisímetro tem capacidade volumétrica de 2,059 m3 e uma área superficial de 2,086 m2 plantada com capim pangola (Digitaria decumbens Stent.). Os testes preliminares de calibração, numa faixa de até 50 mm de lâmina d’água, com retiradas progressivas de volume de 1 dm3 dostravesseiros hidráulicos, revelaram excelentes respostas em todos os testes. O lisímetro operou com uma precisão final de campo de 0,143 mm, com um volume de 14 dm3. A estabilidade do lisímetro foi elevada, sendo o maior erro médio posicicional medido de 3,93 %. O desempenho do lisímetro segundo o índice de Willmott, tomando-se o método Penmam-Monteith como padrão, foi “Péssimo” para medidas em escala diária e “Mal” em dados tridiais, revelando o forte efeito advectivo local sobre a evapotranspiração. O mesmo efeito foi evidenciado sobre as leituras dos tanques de evaporação, que também tiveram desempenho insatisfatório em relação ao método padrão.
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Carlson, Tyson David, and Tyson David Carlson. "Effect of velocity and water content on the gas-phase partitioning tracer test for the in-situ measurement of soil-water content in a large weighing lysimeter." Thesis, The University of Arizona, 2000. http://hdl.handle.net/10150/626925.
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This thesis describes research conducted to evaluate the efficacy of the gas-phase
partitioning tracer method for measuring bulk soil-water content. A series of tracer
experiments were conducted at two velocities and water contents in a well instrumented
weighing lysimeter. The method is based on introducing gas-phase conservative and
water-partitioning tracers into the system. The partitioning tracer dissolves into the
water, which retards its movement with respect to a non-partitioning tracer. This
retardation is a function of the soil-water content. The soil-water contents estimated from
comparative moment analyses of the measured breakthrough curves were compared to
values obtained using traditional methods for determining soil-water content. These
methods include: neutron thermalization, time domain reflectometry, gravimetric core
analysis, and soil tension. The results from the tracer test compare favorably at different
velocities and soil-water contents with the data provided by traditional methods. For the
slower velocities, the tracer results yielded soil-water contents of 0.06 and 0.12 while the
traditional methods 'indicated soil-water contents of 0.06 and 0.15. Tracer tests
conducted at higher velocities yielded soil-water contents of 0.05 and 0.11 while
traditional methods indicated soil-water contents of 0.06 and 0.15. This indicates that the
water partitioning tracer method has potential to provide accurate results under a variety
of conditions.
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Medeiros, Patrick Valverde. "Análise da evapotranspiração de referência a partir de medidas lisimétricas e ajuste estatístico de estimativas de nove equações empírico-teóricas com base na equação de Penman-Monteith." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-21052008-090008/.
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A quantificação da evapotranspiração é uma tarefa essencial para a determinação do balanço hídrico em uma bacia hidrográfica e para o estabelecimento do déficit hídrico de uma cultura. Nesse sentido, o presente trabalho aborda a análise da evapotranspiração de referência (ETo) para a região de Jaboticabal-SP. O comportamento do fenômeno na região foi estudado a partir da interpretação de dados de uma bateria de 12 lisímetros de drenagem (EToLis) e estimativas teóricas por 10 equações diferentes disponíveis na literatura. A análise estatística de correlação indica que as estimativas da ETo por equações teóricas comparadas à EToLis medida em lisímetro de drenagem não apresentaram bons índices de comparação e erro. Admitindo que a operação dos lisímetros não permitiu a determinação da ETo com boa confiabilidade, propôs-se um ajuste local das demais metodologias de estimativa da ETo, através de auto-regressão (AR) dos ruídos destas equações em comparação com uma média anual estimada pela equação de Penman-Monteith (EToPM), tomada como padrão, em períodos quinzenal e mensal. O ajuste através de regressão linear simples também foi analisado. Os resultados obtidos indicam que a radiação efetiva é a variável climática de maior importância para o estabelecimento da ETo na região. A estimativa pela equação de Penman-Monteith apresentou excelente concordância com as equações de Makkink (1957) e do balanço de energia. Os ajustes locais propostos apresentaram excelentes resultados para a maioria das equações testadas, dando-se destaque às equações da radiação solar FAO-24, de Makkink (1957), de Jensen-Haise (1963), de Camargo (1971), do balanço de radiação, de Turc (1961) e de Thornthwaite (1948). O ajuste por regressão linear simples é de mais fácil execução e apresentou excelentes resultados.The quantification of the evapotranspiration is an essential task for the determination of the water balance in a watershed and for the establishment of the culture´s water deficit. Therefore, the present work describes the analysis of the reference evapotranspiration (ETo) for the region of Jaboticabal-SP. The phenomenon behavior in the region was studied based on the interpretation of 12 drainage lysimeters data (EToLis) and on theoretical estimates for 10 different equations available in the Literature. An statistical analysis indicated that the theoretical ETo estimates compared with the EToLis did not present good indices of comparison and error. Admitting that the lysimeters operation did not allow a reliable ETo determination, a local adjustment of the theoretical methodologies for ETo estimate was considered. An auto-regression (AR) of the noises of these equations in comparison with the annual average estimate for the Penman-Monteith equation (EToPM), taken as standard, has been performed in fortnightly and monthly periods. The adjustment through simple linear regression has also been analyzed. The obtained results indicate that the effective radiation is the most important climatic variable for the establishment of the ETo in the region. The Penman-Monteith estimate presented excellent correlation to the estimates by Makkink (1957) equation and the energy balance. The local adjustments presented excellent results for the majority of the tested equations, specially for the solar radiation FAO-24, Makkink (1957), Jensen-Haise (1963), Camargo (1971), radiation balance, Turc (1961) and Thornthwaite (1948) equations. The adjustment by simple linear regression is of easier execution and also presented excellent results.
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Silva, Leonardo Duarte Batista da. "Evapotranspiração do capim tanzânia (Panicum maximum Jacq.) e grama batatais (Paspalum notatum flugge) utilizando o método do balanço de energia e lisímetro de pesagem." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-22052003-141207/.
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A irrigação de pastagens no Brasil apresentou um crescimento acentuado nos últimos anos, porém devido a ausência de pesquisas sobre a aplicação de água em pastagens, o manejo da irrigação não vem sendo realizado de maneira racional. Os objetivos deste trabalho foram avaliar as relações entre a irradiância solar global e a radiação líquida sobre superfícies vegetadas com capim tânzania (Panicum maximum Jacq.) e com grama batatais (Paspalum notatum flugge); determinar a evapotranspiração do capim tânzania, por meio das medidas de lisímetro de pesagem; aplicar o método do balanço de energia para a estimativa da evapotranspiração do capim tânzania, por meio de um sistema automático de razão de Bowen; e comparar os valores de evapotranspiração do capim tanzânia, medidos em lisímetro de pesagem com os estimados pelo balanço de energia por meio de um sistema automático de razão de Bowen. O experimento foi conduzido em Piracicaba, estado de São Paulo. Por meio de um lisímetro de pesagem e um sistema automático de razão de Bowen foram obtidos valores de evapotranspiração do capim tanzânia (ETc). Também foram obtidos dados de irradiância solar global (Qg) e radiação líquida (Rn) sobre grama batatais e capim tanzânia. Os dados foram coletados diariamente e analisados, estatisticamente, mediante análise de regressão. Os modelos de regressão linear de estimativa da radiação líquida encontrados foram Rn = 0,5418.Qg (r 2 = 0,9297) para uma superfície gramada e Rn = 0,5613.Qg (r 2 = 0,8719) para uma superfície vegetada pelo capim tanzânia. A evapotranspiração média do capim tanzânia foi de 4,13 mm.d -1 , segundo o balanço de energia e 4,34 mm.d -1 , obtido pelo lisímetro de pesagem. Com base nos resultados, concluiu-se que o valores de evapotranspiração diários e horários do capim tanzânia medidos pelo sistema automático de razão de Bowen, foram afetados pelo efeito advectivo e pela precipitação, mas apesar disso houve uma razoável correlação com as medidas feitas em lisímetro de pesagem; e o estabelecimento das relações apresentadas neste trabalho mostra que os saldos de radiação em superfície gramada, assim como no capim tanzânia, podem ser estimados satisfatoriamente a partir da irradiância solar global, tendo a necessidade de se considerar suas variações sazonais.Pasture irrigation presented a large growth in Brazil in recent years. However, the lack of research on pasture water use has led to inefficient irrigation management practices. The objectives of this work were: to evaluate the relationships between global solar irradiance and net radiation on surfaces covered with Guinea grass (Panicum maximum Jacq.) and Bahia grass (Paspalum notatum flugge); to determine the evapotranspiration of Guinea grass through weighing lysimeter measurements; to apply the energy balance method to estimate the evapotranspiration of Guinea grass by means of an automated Bowen ratio system; and finally to compare the evapotranspiration of Guinea grass measured by a weighing lysimeter versus the evapotranspiration estimated by the automated Bowen ratio energy balance system.. Evapotranspiration (ETc) was obtained for Guinea grass by means of a weighing lysimeter and an automated Bowen ratio system. Global solar irradiance (Qg) and the net radiation (Rn) over Bahia grass and Guinea grass were also obtained. The data were collected daily and statistically analyzed through regression analysis. The linear regression models for Rn estimates were Rn = 0,5418.Qg (r 2 = 0,9297) for a Bahia grass surface and Rn = 0,5613.Qg (r 2 = 0,8719) for a surface covered with Guinea grass. Guinea grass average evapotranspiration was 4.13 mm.day -1 by the energy balance method and 4.34 mm.day -1 as measured by the weighing lysimeter. The results led to the conclusion that the daily and hourly evapotranspiration values of Guinea grass obtained by the Bowen ratio automated system, were affected by the advection and by precipitation. Despite that, it was possible to obtain a correlation between the Bowen ratio evapotranspiration and measurements with the weighing lysimeter. The results show that the net radiation over Bahia grass and Guinea grass can satisfactorily be estimated from the global solar irradiance as long as seasonal variations are taken into account.
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Bode, Ralf. "Auslaugung anorganischer Schadstoffe aus Abfall- und Altlastmaterialien." Doctoral thesis, [S.l.] : [s.n.], 2005. http://hdl.handle.net/11858/00-1735-0000-0006-B310-C.
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Prédélus, Dieuseul. "Rôle des hétérogénéités texturale et structurale du sol sur le transfert et la rétention des nanoparticules dans la zone non saturée : Expérimentation et modélisation." Thesis, Vaulx-en-Velin, Ecole nationale des travaux publics, 2014. http://www.theses.fr/2014ENTP0006/document.
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La production croissante des nanoparticules issues du développement des nanotechnologies et leur incorporation dans des produits de consommation vont inévitablement conduire à leur introduction dans l’environnement. Ces particules peuvent constituer un vecteur de substances polluantes en raison du transport facilité des contaminants organiques ou inorganiques potentiellement adsorbés sur leurs surfaces ou représentent elles-mêmes un risque pour l’environnement et la santé humaine. La zone non saturée joue une fonction importante de filtration naturelle des eaux de recharge des nappes. Les mécanismes de transport et de rétention des nanoparticules à travers cette zone sont complexes du fait des hétérogénéités de type structural et textural de celle-ci. Ces hétérogénéités sont à l'origine des écoulements préférentiels et d’un grand nombre de facteurs d'interaction physico-chimiques liés aux propriétés des nanoparticules et de la zone non saturée elle-même. L'objectif de la thèse est de mieux comprendre les effets de ces hétérogénéités sur le transport des nanoparticules dans un milieu non saturé hétérogène afin de mieux prévenir le devenir des nanoparticules dans le sol. Dans ce contexte, trois matériaux granulaires (un sable et des mélanges sable-gravier) ont été mis en place en colonne (10 cm de diamètre x 30 cm de hauteur) et dans le lysimètre LUGH du LEHNA (100 x 160 x 100 cm3) pour simuler le transport des nanoparticules dans le sol. Le but est de déterminer le rôle des hétérogénéités texturale (différentes granulométries) et structurale (barrière capillaire) du sol, en prenant en compte les effets de la force ionique de la solution et de la vitesse d’écoulement sur le transfert des nanoparticules en conditions non saturées. Des nanoparticules de silice marquées par des molécules organiques fluorescentes ont été développées en tant que nanotraceur particulaire dans le cadre de cette étude, l’ion bromure a été utilisé pour caractériser l’écoulement de l’eau. Le modèle de transfert de non équilibre hydrodynamique à fractionnement de l'eau en deux phases mobile et immobile, MIM, incluant un terme de rétention et de relargage des nanoparticules, décrit correctement les courbes d'élution de nanoparticules, pour les expériences en colonne. Cette étude a permis de caractériser les effets liés aux différentes tailles des grains du sol et à la barrière capillaire sur la rétention des nanoparticules. Les expériences réalisées avec différentes forces ioniques montrent que pour les forces ioniques comprises entre 1 et 50 mM, la rétention est croissante comme prédit la théorie DLVO ; cependant à partir d’une force ionique supérieure à 100 mM il se produit une inversion de la rétention. Lorsque la vitesse d’écoulement diminue, la rétention augmente, probablement en partie à l’interface air-eau. Le lysimètre LUGH a permis d’identifier le rôle de la barrière capillaire sur la rétention des nanoparticules. Un modèlenumérique 3D basé sur l’équation de Richards pour l’écoulement et les équations convection dispersion couplées avec un module de rétention pour les nanoparticules a été dévelopé. Les résultats montrent que la rétention a augmenté à l’interface sable-milieu bimodal. Le profil de rétention de nanoparticules indique qu’elles sont majoritairement retenues en surface du sol, puis la rétention diminue avec la profondeur, pour les expériences réalisées en colonne. Le nanotraceur constitue un outil puissant pour l’étude du rôle des hétérogénéités dans le transfert des particules dans un sol non saturéIncreasing production of nanoparticles from nanotechnology development and incorporation into consumer products will inevitably lead to their introduction into the environment. These particles can be a vector of pollutants due to the facilitated transport of organic and inorganic contaminants potentially adsorbed on their surfaces or represent a risk to the environment and human health themselves. The unsaturated zone plays an important function of natural water filtration recharge. The transport and retention mechanisms of nanoparticles through this zone are complex due to the structural and textural soil heterogeneities. These heterogeneities are causing preferential flows and are responsible a large number of physical and chemical interaction related to the nanoparticles properties. The aim of the thesis is to better understand effects of soil heterogeneities on the transport of nanoparticles in a heterogeneous unsaturated media to better prevent the fate of nanoparticles in the vadose zone. In this context, three granular materials (sand and sand - gravel mixtures) were introduced in column (10 cm diameter x 30 cm high) and the lysimeter LUGH of Lehna (100 x 160 x 100 cm3) to simulate the transport of nanoparticles in the soil. The goal is to determine the role of heterogeneous textural (different sizes) and structural (barrier capillary) heterogeneities of the soil, taking into account the effects of the ionic strength of the solution and the flow rate on the transfer of the nanoparticles in unsaturated conditions. Silica nanoparticles labeled with fluorescent organic molecules have been developed as particulate v in this study, the bromide ion has been used to characterize the flow of water. The transfer model of non-equilibrium hydrodynamic fractionation of water and two mobile and immobile phases, MIM, including a retention and release term of the nanoparticles, properly described breakthrough curves of nanoparticles on column experiments. This study allowed to characterize the effects related of different grain sizes of soil and capillary barrier on the nanoparticle retention. Experiments with different ionic strengths show for the ionic strength between 1 and 50 mM, the retention increased as predicted by the DLVO theory. However, from an ionic strengh greater than 100 mM an inversion retention occurs. When the flow rate decreases, retention increases, air - water interface increases and trapps probably the nanoparticles. Lysimeter LUGH allowed to identify the role of the capillary barrier on the retention of nanoparticles. A 3D numerical model based on Richards equation for flow and the convection dispersion equations coupled with a mechanical module for nanoparticle trapping was developed. Results show retention increased in the sand-bimodal interface. The retention profile indicates that nanoparticles are predominantly retained at the soil surface, then the retention decreases with depth, for the column experiments. The nanotracer is a powerful tool for studying the role of heterogeneous in the transfer of particles in an unsaturated soil
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Kaufmann, Vander. "Processo hidrológico e transporte de espécies químicas produzidos por chuva intensa simulada em solos do sul do Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/78868.
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As atividades agrícolas promovem modificações na estrutura física do solo e nas interações que ocorrem no seu interior. As mudanças promovidas nestas atividades podem gerar alterações do processo hidrogeoquímico no solo. Este estudo tem por objetivo estudar o processo hidrológico e o transporte de espécies químicas em solos agrícolas do Sul do Brasil, quando submetidos à chuva de alta intensidade, em lisímetros de drenagem, que são dispositivos experimentais. Sete lisímetros instalados em quatro bacias hidrográficas situadas nos estados do Sul do Brasil foram utilizados nos experimentos, apresentando os mesmos procedimentos metodológicos de dimensionamento e instalação. Nestes, foram realizadas simulações, com diferentes intensidades de chuva, com monitoramento do escoamento superficial e o de drenagem, analisadas quimicamente para as espécies químicas amônio, nitrato, nitrito, fosfato, carbono orgânico e inorgânico total. Foram realizados 77 ensaios de simulação de chuva, com intensidades de chuva variando entre 30 e 140 mm h-1, correspondendo a um período de retorno da ordem de 1 a 1000 anos, respectivamente, correspondendo a chuvas extremas. As séries de dados geradas foram analisadas quanto às suas evoluções temporais e espaciais, magnitude e o processo de transporte envolvido. Os modelos SWAP - Soil, Water, Atmosphere, Plant Environment e ANIMO - Agricultural Nutrient Model foram aplicados às séries, visando avaliar o processo hidrogeoquímico representados. Os modelos são de base física e apropriados para uso em escala de lisímetro. A geração de escoamento superficial, as taxas de infiltração de água no solo e a drenagem interna, em eventos pluviométricos de alta intensidade são influenciadas pelas práticas de manejo e pelo estádio de desenvolvimento da cobertura vegetal e a própria intensidade da chuva. Para elevadas intensidades de chuva tem-se o aumento da água retida na superfície, com consequente alteração na carga hidráulica, proporcionando aumento das taxas de infiltração e do escoamento no perfil do solo. As simulações de chuvas intensas mostram que as concentrações de nitrato nas águas de escoamento superficial e de drenagem são mais elevadas do que aquelas de amônio, nitrito, fosfato, carbono orgânico total e carbono inorgânico. O modelo SWAP simulou adequadamente os componentes do balanço hídrico no lisímetro nas escalas de tempo diário e das chuvas simuladas. Os coeficientes de eficiência de Nash-Sutcliffe na calibração e na verificação, na escala diária, foram superiores a 0,8 para o escoamento de drenagem. Para o nitrato e o fosfato, o modelo ANIMO simulou corretamente as concentrações nas datas de coletas de amostras de águas do escoamento superficial e de drenagem da série de dados diários. Nos períodos dos ensaios de chuvas simuladas, o modelo SWAP apresentou coeficientes de eficiência da ordem de 0,8 para a calibração e verificação do escoamento de drenagem. As evoluções das vazões dos ramos de ascensão e das vazões máximas dos hidrogramas foram adequadamente reproduzidas. O modelo ANIMO simulou com boa precisão as variações temporais das concentrações de nitrato e de fosfato nos períodos de verificação e de calibração das séries de ensaios de simulação de chuva.Agricultural activities promote modifications in the physical structure of the soil and the interactions that occur within. The changes promoted these activities can generate changes in hydrogeochemical processes in the soil. This study aims to the hydrological processes and transport of chemical species in agricultural soils in southern Brazil, when subjected to rain of high intensity in drainage lysimeters, are experimental devices. Seven lysimeters installed in four catchment areas in the southern states of Brazil were used in the experiments, which present the same methodology and manufacturing facility. In these were performed simulations with different rainfall intensities. Were monitored runoff, drainage and analyzed water samples collected for chemical species ammonium, nitrate, nitrite, phosphate, total organic and inorganic carbon. 77 tests were performed to simulate rain, precipitation intensities ranging between 30 and 140 mm h-1, corresponding to return period of about 1 to 1,000 years, respectively, corresponding to extreme rainfall. The datasets generated were analyzed for their spatial and temporal evolutions, their magnitudes and transport processes involved. The models SWAP - Soil, Water, Atmosphere, Environment and Plant and ANIMO - Agricultural Nutrient Model, was applied to the series, to evaluate the hydrogeochemical processes represented. The models are based on physical and suitable for use in lysimeter scale. The generation of runoff, infiltration rates and soil water drainage built in high intensity rainfall events are influenced by management practices and the development stage of the vegetation cover and the very intensity of precipitation. For high intensity rainfall has increased water retained in the surface, with a consequent change in hydraulic head, providing increased rates of infiltration and runoff in the soil profile. The simulations show that the heavy rainfall nitrate concentrations in water runoff and drainage are higher than those of ammonium, nitrite, phosphate, total organic carbon and inorganic carbon. The SWAP model adequately simulated the water balance components in the lysimeter and daily time scales of simulated rainfall. The coefficient of efficiency Nash-Sutcliffe calibration and verification in a daily were more than 0.8 drain for disposal. For nitrate and phosphate, the model correctly simulated ANIMO concentrations on the dates of sample collection of water runoff and drainage series of daily data. During periods of rainfall test, the model presented SWAP efficiency ratios on the order of 0.8 for calibration and verification of drainage outlets. The evolutions of the flow of arms to rise and peak flows of hydrographs were properly reproduced. The model adequately simulated ANIMO temporal variations in the concentrations of nitrate and phosphate during periods of verification and calibration of the test suites rainfall simulation.
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Peruchi, Fernanda. "Evapotranspiração real a partir de medidas lisimétricas e sob diferentes condições de disponibilidade hídrica." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-12112009-152605/.
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A evapotranspiração pode ser responsável por mais da metade da saída de água de uma bacia hidrográfica, sendo uma variável importante para o balanço hídrico e para a estimativa da recarga. Nesse sentido, objetivou-se com este trabalho analisar a evapotranspiração de referência (ETo) e real (ETr) para a região de Jaboticabal-SP, assim como verificar a influência da umidade do solo na evapotranspiração. A variação da evapotranspiração de referência foi estudada a partir da interpretação de dados de uma bateria de seis lisímetros de drenagem (EToLis) e estimativas teóricas por três equações diferentes disponíveis na literatura (Tanque Classe A, Thornthwaite e Penman Monteith FAO 56 utilizando a radiação solar global estimada, observada e todas as variáveis observadas). A evapotranspiração real foi obtida por meio de dados de uma bateria de três lisímetros operando em condições reais de campo e a partir do balanço hídrico seqüencial de Thornthwaite e Mather (1955) utilizando a evapotranspiração de referência obtida pelos três modelos teóricos. Outros três lisímetros receberam irrigações esporádicas e obtiveram-se outros valores de evapotranspiração, a fim de comparar o comportamento da evapotranspiração sob três disponibilidades de água no solo. A análise estatística de correlação indica que as estimativas da ETo por equações teóricas comparadas à EToLis medida em lisímetro de drenagem não apresentaram bons índices de comparação e erro. Admitindo que a operação dos lisímetros não permitiu a determinação da ETo com boa confiabilidade, comparou-se os métodos com a equação de Penman Monteith FAO 56 utilizando todas as variáveis observadas. Observou-se ótima correlação entre a equação de Penman Monteith FAO 56 com os modelos utilizando a radiação solar global observada e estimada e com o Tanque Classe A. No tocante à evapotranspiração real, houve boas correlações entre os valores medidos pelos lisímetros e os valores estimados pelo balanço hídrico de Thornthwaite e Mather. Melhor correlação foi verificada quando se utilizou o valor da CAD calculada em função dos parâmetros físicos do solo. Os valores de ETr obtidos através do balanço hídrico utilizando a ETo estimada por Penman Monteith utilizando a radiação solar global observada apresentou a melhor correlação com os dados lisimétricos. Com relação à variação de umidade do solo, verificou-se um comportamento distinto entre as evapotranspirações observando um aumento da ET de acordo com o aumento do número de irrigações.The evapotranspiration can be responsible for more than the half of the water that leaves a watershed, being an important variable for the water balance and for estimating the recharge. In this direction, the objective of this study was to analyse the reference (ETo) and actual (ETr) evapotranspiration for the region of Jaboticabal-SP, Brazil, as well as to verify the influence of the soil water content in the evapotranspiration. The variation of the reference evapotranspiration was studied based on data of a battery of six drainage lysimeters (EToLis) and tree different theoretical models were used (Tanque Classe A, Thornthwaite and Penman Monteith FAO 56 using the estimated and observed global solar radiation and all the variables observed). The actual evapotranspiration data were obtained from a battery of three lysimeters operating in real field conditions and from the water balance of Thornthwaite and Mather (1955), using as reference evapotranspiration the values from the three theoretical models. Others three lysimeters received irrigation sporadically and others values of evapotranspiration were measured, in order to compare the behavior of the evapotranspiration under three availabilities soil water content. The statistical correlation analysis indicates that the estimates of ETo from theoretical equations compared to the EToLis measured in lysimeter of draining did not present good indices of comparison and error. Aware that the operation of the lysimeters did not allow the determination of the ETo with good trustworthiness, one compared the methods with the equation of Penman Monteith FAO 56 using all the observed variables. An excellent correlation was observed between the equation of Penman Monteith FAO 56 with the models using observed global solar radiation and estimated and with Tanque Classe A. Regarding actual evapotranspiration, there were good correlations between the values measured for the lysimeters and the estimated values for water balance of Thornthwaite and Mather. The values of ETr through the water balance using the ETo esteem for Penman Monteith using the observed global solar radiation presented the best correlation with the lisimeters data. Regarding to the variation of soil water content, a distinct behavior was verified between the evapotranspirations in accordance with observing an increase of the ET the increase of the irrigation number.
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Ara?jo, M?rio S?rgio Paiva de. "Coeficientes da cultura e produtividade do cons?rcio de milho caatingueiro com feij?o-de-porco e do repolho plantado na palhada." Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/1807.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
The study of crops water demand throughout its development cycle enables the rational use of water, and this scarce study for maize intercropped with bean-to-pig and cabbage grown in maize straw. The objective of this work was to determine the crop evapotranspiration (ETc) and crop coefficients (Kc) of ?caatingueiro? corn under monoculture and intercropping system with bean-to-pig, , and ?fuyutoyo? cabbage planted on the straw, and to check the influence of the consortium in the production of corn and cabbage. The study was conducted in Serop?dica-RJ, using weighing lysimeters, the Kc values were determined by the ratio between ETc and the reference evapotranspiration (ETo). The ETo was estimated by the FAO Penman-Monteith model. The ETc values were calculated using the water balance of the lysimeter-cropp-soil system. The cycle caatingueiro corn intercropped with jack bean and monoculture was March 18 to June 25, the Kc values were calculated for the four stages of crop development. The corn planted in three areas, one with corn intercropping and jack beans with full irrigation (C100), the other with intercropped with deficit irrigation (CD75) and the last with monoculture (Mon). Four samples were taken throughout the cycle to analyze the leaf area, plant height and cob insertion and end of the cycle data of productivity and of water use efficiency (WUE) were measured. The fuyutoyo cabbage was transplanted from the tray to the area 33 days and the cycle after transplant lasted from July 17 to October 26, the Kc values were calculated for the four stages of development. The Kc values for each phase of crop development in the intercropping system were: I (0.78); II (1.06); III (1.10) and IV (1.01), for the monoculture system, the kc values were: I (0.62); II (0.92); III (1.27) and IV (0.89). The corn had a Degree-Days accumulation of 1416.5 ? C throughout cycle, there was not significant difference in leaf area and number of corn cob between the three areas, The C100 area showed smaller values of plant height for all measurements, since the CD75 was lower than Mon only the first measurement. The productivity of C100 (6937.17 kg / ha) did not differ from that found in Mon (6055.34 kg / ha) and was higher than that found in CD75 (4328.91 kg / ha). The C100 showed higher WUE than CD75 and was similar to values found for Mon. The Cabbage has kc values for each phase of crop development: I (1.02); II (1.03); III (1.05) and IV (1.01) and had a degrees-day accumulation of 1439.2 ? C. The productivity cabbage RMon (34.76 T / ha) was higher than the area RC100 (18.99 T / ha), the WUE was lower in RC100. The RCD75 did not differ in the statistical tests. Corn consortium with beans had good result in corn yields in the area C100 and lower productivity in CD75 area, and had no satisfactory result in cabbage productivity in the area RC100
O estudo da demanda h?drica das culturas ao longo do seu ciclo de desenvolvimento possibilita o uso racional da ?gua, sendo esse estudo escasso tanto para consorcia??o de milho com feij?o-de-porco, quanto para o repolho cultivado em palhada de milho. Objetivou-se determinar a evapotranspira??o da cultura (ETc) e os coeficientes de cultura (Kc) do milho caatingueiro, consorciado com feij?o-de-porco e em sistema de monocultivo, e do repolho fuyutoyo plantado sobre a palhada remanescente, assim como verificar a influ?ncia do cons?rcio na produ??o do milho e do repolho. O estudo foi realizado em Serop?dica-RJ, utilizando lis?metros de pesagem. Os valores de Kc foram determinados por meio da raz?o entre ETc e ETo (evapotranspira??o de refer?ncia). A ETo foi estimada pela metodologia proposta por Penman-Monteith FAO, enquanto a ETc foi obtida pelo balan?o h?drico do sistema lis?metro-cultura-solo. O ciclo do milho caatingueiro consorciado com feij?o-de-porco e monocultivo foi de 18 de mar?o a 25 de junho de 2015, e teve Kc estimado para as quatro fases de desenvolvimento da cultura, o milho foi plantado em tr?s ?reas, uma com consorcia??o de milho e feij?o-de-porco aplicando-se irriga??o plena (C100), outra com consorcia??o e irriga??o em d?ficit (CD75) e a ?ltima com monocultivo e irriga??o plena (Mon). Foram realizadas quatro coletas ao longo do ciclo para analisar a ?rea foliar, altura da planta e a inser??o da espiga e no final do ciclo dados de produtividade e efici?ncia do uso da ?gua (EUA) foram medidos. As mudas do repolho fuyutoyo foram transplantadas para a ?rea com 33 dias ap?s a semeadura e o ciclo ap?s transplante durou de 17 de julho a 26 de outubro de 2015, o qual teve o Kc para as quatro fases de desenvolvimento. O repolho foi transplantado na palhada do milho em tr?s ?reas, ficando dividido em repolho onde tinha cons?rcio sem deficit (RC100) e com d?ficit (RCD75) e repolho onde tinha monocultivo (RMon) sendo avaliado dados de produtividade no final do ciclo. Os valores de Kc para cada fase de desenvolvimento do milho em cons?rcio com a feij?o-de-porco foram: I (0,78); II (1,06); III (1,10) e IV (1,01), para o monocultivo, os valores foram: I (0,62); II (0,92); III (1,27) e IV (0,89). O milho teve um acumulo de graus-dias de 1416,5 ?C durante todo ciclo, n?o sendo encontrada diferen?a significativa na ?rea folia e no n?mero de espiga do milho entre as tr?s ?reas. A ?rea C100 apresentou menores valores de altura de planta em todas as medi??es, CD75 foi inferior ao Mon apenas na primeira medi??o. A produtividade do C100(6937,17 kg/ha) n?o diferiu da encontrada no Mon (6055,34 kg/ha) e foi superior a encontrada no CD75(4328,91 kg/ha). O C100 apresentou maior EUA que o CD75 e foi semelhante aos valores encontrados para o Mon. O repolho teve valores de Kc para cada fase de desenvolvimento de: I (1,02); II (1,03); III (1,05) e IV (1,01), com acumulo graus-dia de 1439,2 ?C. A produtividade do repolho RMon (34,76 T/ha) foi superior ? da ?rea RC100 (18,99 T/ha), tendo o mesmo comportamento na EUA. O RCD7 n?o diferiu nos testes estat?stico com rela??o aos demais tratamentos. Pode-se concluir cons?rcio de milho com feij?o-de-porco teve boa resposta na produtividade do milho na ?rea C100 e uma menor produtividade na ?rea CD75, e n?o teve resposta satisfat?ria na produtividade do repolho na ?rea RC100
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Cardoso, Antonio J. "Relationship of waste characteristics to the formation of mineral deposits in leachate collection systems." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001266.
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Paul, George. "Evaluation of surface energy balance models for mapping evapotranspiration using very high resolution airborne remote sensing data." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/15914.
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Doctor of PhilosophyDepartment of Agronomy
P.V. Vara Prasad
Agriculture is the largest (90%) consumer of all fresh water in the world. The consumptive use of water by vegetation represented by the process evapotranspiration (ET) has a vital role in the dynamics of water, carbon and energy fluxes of the biosphere. Consequently, mapping ET is essential for making water a sustainable resource and also for monitoring ecosystem response to water stress and changing climate. Over the past three decades, numerous thermal remote sensing based ET mapping algorithms were developed and these have brought a significant theoretical and technical advancement in the spatial modeling of ET. Though these algorithms provided a robust, economical, and efficient tool for ET estimations at field and regional scales, yet the uncertainties in flux estimations were large, making evaluation a difficult task. The main objective of this study was to evaluate and improve the performance of widely used remote sensing based energy balance models, namely: the Surface Energy Balance Algorithm for Land (SEBAL), Mapping Evapotranspiration at high Resolution and with Internalized Calibration (METRIC), and Surface Energy Balance System (SEBS). Data used in this study was collected as part of a multi-disciplinary and multi-institutional field campaign BEAREX (Bushland Evapotranspiration and Agricultural Remote Sensing Experiment) that was conducted during 2007 and 2008 summer cropping seasons at the USDA-ARS Conservation and Production Research Laboratory (CPRL) in Bushland, Texas. Seventeen high resolution remote sensing images taken from multispectral sensors onboard aircraft and field measurements of the agro-meteorological variables from the campaign were used for model evaluation and improvement. Overall relative error measured in terms of mean absolute percent difference (MAPD) for instantaneous ET (mm h[superscript]-[superscript]1) were 22.7%, 23.2%, and 12.6% for SEBAL, METRIC, and SEBS, respectively. SEBAL and METRIC performances for irrigated fields representing higher ET with limited or no water stress and complete ground cover surfaces were markedly better than that for dryland fields representing lesser ET and greater soil water deficits with sparser vegetation cover. SEBS algorithm performed equally well for both irrigated and dryland conditions but required accurate air temperature data. Overall, this study provides new insights into the performance of three widely used thermal remote sensing based algorithms for estimating ET and proposed modifications to improve the accuracy of estimated ET for efficient management of water resources.
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Quaglia, Luciano. "Calibração de um lisímetro de pesagem para monitoramento da evaporação do solo sem cobertura vegetal." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11131/tde-24052005-145355/.
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Lisímetros de pesagem tem custos de implantação e manutenção elevados e nem sempre produzem resultados satisfatórios devido a impossibilidade de representarem as muitas situações que ocorrem num sistema de produção agrícola. Foi idealizado um sistema mais simplificado de montagem de lisímetro de pesagem para obtenção de perda de água do solo. Tal sistema utiliza apenas uma célula de carga em cada lisímetro, e mis uma célula no sistema de drenagem. Devido a essa possibilita também a medida da evaporação durante o processo da drenagem. O custo médio da instalação de uma bateria de três lisímetros em Piracicaba, SP, foi de aproximadamente US$ 900,00. Foram obtidos valores de massa satisfatórios para períodos diários, horários e a cada trinta minutos. Existe grande correlação entre a massa do lisímetro e a umidade do solo. Houve grande oscilação da evaporação do solo ao longo do dia, maior do que a ETo calculada. Os valores de coeficiente de evaporação, Ke, obtidos se mostraram-se consistentes.Foram identificadas as fases de rápida redução de Ke e a de redução lenta, respectivamente para as faixas de umidade intermediária e seca. Foi possível realizar ajuste estatisticamente significativo de um modelo logarítmico do coeficiente de evaporação (Ke) em função de evapotranspiração de referência acumulada (ETo) ou da evaporação do tanque classe A acumulada(ECA). Os modelos para estimativa de ARM e de Ke em função dos índices de seca ∑EToPM e ∑ECA mostraram-se adequadas para seus propósitos, podendo ser também utilizadas para a estimativa da evaporação do solo nu (Es) considerando-se esta como a variação do ARM da água do solo.Weighing lysimeters have high installation cost and require frequent maintenance and sometimes they do not produce satisfactory results due to the impossibility to represent all the situations that happen in an agricultural system. A simplified weighing lysimeter was developed to obtain soil water loss. Such a system just uses a load cell per lysimeter and another cell in the drainage system, which makes possible to measure of the evaporation during drainage process. The average cost of installation of a battery of three lysimeters in Piracicaba, SP, was approximately US$ 900. Satisfactory daily mass values were obtained, as well as for hourly and thirty minutes periods. A high correlation between the mass of the lysimeters and soil moisture was observed. The variation of soil evaporation along the day was larger than the variation obtained with calculated ETo. The values of evaporation coefficient, (Ke), were consistent. The phases of fast and slow reduction of Ke were identified respectively for medium and low soil water content. Was possible to adjust a logarithmic model to the relation ship between evaporation accumulated reference evapotranspiration (∑ETo) and accumulated evaporation from class A pan (∑ECA). The models for estimating (ARM) and Ke in function of the drought indexes ∑EToPM and ∑ECA were water storage in the soil appropriate and can be used to estimate evaporation of a bare soil, which is considered as the variation of ARM.
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Libardi, Luís Guilherme Polizel. "Evapotranspiração e coeficiente de cultura de mudas pré-brotadas de cana-de-açúcar para manejo de irrigação em cultivo protegido." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152608.
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A produção de mudas pré-brotadas (MPB) de cana-de-açúcar é um método inovador que visa aumentar a taxa de multiplicação da cultura. O sistema é conduzido em cultivo protegido, no qual o manejo correto de irrigação é fator essencial para manter a qualidade da produção. O objetivo do estudo foi expor detalhes da construção e calibração de três lisímetros de pesagem de baixo custo e utilizá-los para determinar evapotranspiração de cultura (ETc) e coeficiente de cultura (Kc) de MPB de três cultivares de cana-de-açúcar (CTC9005HP, RB966928 e SP87365), aliados à análise de crescimento, para manejo de irrigação em cultivo protegido. Três lisímetros de pesagem foram construídos especificamente para MPB em casa de vegetação da Usina São Martinho (São Martinho S/A), cada qual com área de 0,6909 m2 (1179 mm x 586 mm), profundidade de 400 mm e apoiados sobre 3 células de carga. A calibração dos lisímetros demonstrou precisão e acurácia na detecção de variações de massa equivalente em torno de 0,1 mm pelos equipamentos e magnitude de histerese que não comprometeu as avaliações de evapotranspiração. O custo de equipamentos foi baixo, exceto o sistema de aquisição de dados. A determinação de ETc e cálculo de ETo pelo método FAO-56 possibilitaram inferir valores de Kc ao longo do ciclo de produção. O consumo hídrico, determinado pela ETc, variou de 3,0 a 6,9 mm d-1 na CTC9005HP, 3,1 a 6,8 mm d-1 na RB966928 e 2,9 a 6,6 mm d-1 na SP87365. Kc teve elevação de 1,00 a 1,46 na CTC9005HP, 1,02 a 1,53 na RB966928 e 1,02 a 1,49 na SP87365. A poda das folhas aos 37 dias após a transferência reduziu ETc e, consequentemente, Kc dos tratamentos. Altura de colmos foi superior em SP87365 e CTC9005HP e diâmetro de colmos em RB966928. SP87365 foi superior à CTC9005HP nas avaliações foliares. Massas frescas e secas de colmos e total não diferiram entre cultivares. Épocas de avaliação apresentaram diferenças nas avaliações, confirmando o crescimento das plantas. Portanto, ETc e Kc de MPB foram determinadas por lisímetros de precisão de baixo custo, aliados à análise de crescimento, para manejo de irrigação de MPB em cultivo protegido.
The pre-sprouted sugarcane plantlets production system (PSS) is an innovative method to enhance crop multiplication rates. This system is greenhouse-grown, where correct irrigation management is essential to maintain the production quality. The purpose of this study was to detail construction and calibration of three low-cost weighing lysimeters and to use them to determine crop evapotranspiration (ETc) and crop coefficient (Kc), allied to growth analysis, of three sugarcane cultivars (CTC9005HP, RB966928 and SP87365), for irrigation management of greenhouse grown PSS. Three specific PSS weighing lysimeters were built in a greenhouse at São Martinho Mill (São Martinho S/A) and covered 0.6909 m2 (1179 mm x 586 mm) with 400 mm depth supported by 3 load cells. The lysimeters calibration showed precision and accuracy detection of equivalent-mass variations around 0.1 mm and hysteresis that did not compromise evapotranspiration measurements. Low cost materials were used in this study, excluding acquisition data system. Determined ETc and calculated FAO-56 ETo resulted in production cycle Kc values. Water requirement, determined by ETc, ranged from 3.0 to 6.9 mm d-1 in CTC9005HP, 3.1 to 6.8 mm d-1 in RB966928 and 2.9 to 6.6 mm d-1 in SP87365. Kc increased from 1.00 to 1.46 in CTC9005HP, 1.02 to 1.53 in RB966928 and 1.02 to 1.49 in SP87365. Treatments leaves pruning at 37 days after transference to greenhouse decreased ETc and, consequently, Kc. Stalk height was higher in SP87365 and CTC9005HP and stalk diameter in RB966928. SP87365 was superior to CTC9005HP in leaf evaluations. Total and stalk fresh and dry masses did not differ between cultivars. Evaluation periods presented difference in evaluations, confirming plants growth. Therefore, ETc and Kc were successfully determined by built precision low-cost lysimeters, allied to growth analysis, for PSS irrigation management in greenhouse grown.
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Leeder-Kamanda, Götz. "Das Verhalten von BTX-Aromaten in der ungesättigten Bodenzone." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2009. http://nbn-resolving.de/urn:nbn:de:bsz:105-3979693.
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Es wurden Versuche für die ungesättigte Zone duchgeführt, um das Verhalten kleinerer Einträge an Benzen, Toluen und Xylen im Oberboden anschätzen zu können. In einem Vorversuch wurde der Verteilungskoeffizient Gas-Wasser für verschiedene Wässer bestimmt. Der Einfluss der Temperatur hatte einen größeren Einfluss als der Chemismus des Wassers. Die Sorption wurde ermittelt und zeigte sich als ein über sechs Größenordnungen linearer Prozess. Sie ist abhängig vom Humusgehalt. Versuche zur Desorption zeigen Unterschiede zwischen den Aromaten. Xylen desorbiert am langsamsten. Fünf, z.T. mehrmonatige Versuche mit einem großen Laborlysimeter (60 cm Durchmesser, 2 m Länge) zeigten, dass die Korngröße die Diffusion und dichtebedingte Konvektion der gasförmigen Aromaten beeinflusst. Diese Vorgänge sind für den schnellen Transport verantwortlich. Das Sickerwasser bewegt sich deutlich langsamer, transportiert aber die größeren BTX-Mengen. Humushaltige Böden können den Transport in tiefere Bereiche aufgrund von Sorption deutlich reduzieren. Mikrobieller Abbau lässt sich über den Sauerstoffverbrauch nachweisen.
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Júnior, Cícero Renê Almeida Barboza. "Evapotranspiração da lima ácida \'Tahiti\' (Citrus latifolia Tan.) determinada por lisimetria de pesagem." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-14022008-164620/.
Full textAbstract:
O Brasil é o maior produtor mundial de citros, com destaque para o estado de São Paulo, maior produtor nacional. Recentes estudos mostram que a área irrigada de citros no estado tem aumentado significativamente nos últimos anos. Porém, a falta de informações sobre o manejo eficiente da irrigação na cultura do citros é uma das principais dificuldades enfrentadas pelos produtores. Com o intuito de atender essa necessidade, este trabalho teve como objetivos determinar a evapotranspiração de uma planta adulta de limeira ácida \'Tahiti\' (Citrus latifolia Tan.) e o coeficiente de cultivo no período seco (outono - inverno) utilizando a técnica de lisimetria de pesagem. O coeficiente de cultivo (Kc = ETc/ETo) foi calculado considerando-se a contribuição independente da evaporação do solo e transpiração da planta, sendo substituído por dois coeficientes: Ke, um coeficiente de evaporação de água do solo e Kcb, um coeficiente basal de transpiração da cultura. Avaliar os aspectos produtivos e de qualidade de fruto, frente a diferentes níveis de irrigação, com o fornecimento crescente de 50 a 125 % da evapotranspiração da cultura. O experimento foi realizado na ESALQ/ USP em Piracicaba - SP, em uma área irrigada por gotejamento, com plantas espaçadas de 7 x 4 m, sendo que cada planta foi atendida por 4 pontos de molhamento no solo distribuídos de forma eqüidistantes entre si. Foi realizado o monitoramento climático utilizando estação meteorológica automatizada e a obtenção da evapotranspiração da cultura por lisímetro de pesagem. Durante o período de estudo, Kc variou entre 0,82 a 1,18, e Kcb variou entre 0,86 a 1,05. Os resultados mostraram que a irrigação calculada pelo método do Kcb+Ke, tem um ajuste muito bom e representa com precisão o consumo de água pela planta. Os maiores consumos foram observados nos meses de maior temperatura média (abril e setembro). A reposição de 100 % da água evapotranspirada resultou em maior produtividade de frutos de limeira acida \'Tahiti\' em condições de campo. Quanto à qualidade de frutos, não houve diferença significativa entre os níveis de irrigação avaliados.Brazil is the largest world producer of citrus crop, with São Paulo state leading as the largest national producer. Recent studies show that irrigated areas of citrus in the state have been increasing significantly in the last few years. However, lack of information on irrigation management related to this crop is one of the main problems encountered by the farmers. In order to address the above problem, the objective of this work was to determine the evapotranspiration of acid lime adult plant variety \'Tahiti\' (Citrus latifolia Tan.) and the crop coefficient during dry period (autumn - winter) using a weighing lysimeter technique. The crop coefficient (Kc = ETc/ETo) was calculated by considering the independent contribution of the evaporation of the soil and transpiration of the plant, being substituted by two coefficients: Ke, a soil water evaporation coefficient and Kcb, a basal crop coefficient. To evaluate the productive aspects as well as the fruit quality, different irrigation levels were applied in an increasing manner from 50 to 125 % of the crop evapotranspiration. The experiment was carried out at ESALQ / USP in Piracicaba - SP, in a drip irrigated area with plant spacing of 7 x 4 m. Each plant was supplied with four wetting equidistant emitters. The climatic data was obtained by the use of automated meteorological station and the crop evapotraspiration by the use of a weighing lysimeter. During the study period, Kc varied from 0.82 to 1.18, and Kcb varied from 0.86 to 1.05. The results showed that the irrigation amount calculated by the method of Kcb+Ke had a very good water consumption precision by the plant. The highest consumptions were observed in the months of high average temperature (April and September). The reposition of 100 % of the evapotranspirated water resulted in the highest fruit production of acid lime tree variety \'Tahiti\' in field conditions. Irrigation levels had no significant effect at 0.05 level on the quality of the fruits.