Добірка наукової літератури з теми "Soil irrigation"

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Статті в журналах з теми "Soil irrigation"

1

Butts, Christopher L., Ronald B. Sorensen, and Marshall C. Lamb. "Irrigator Pro: Progression of a Peanut Irrigation Scheduling Decision Support System." Applied Engineering in Agriculture 36, no. 5 (2020): 785–95. http://dx.doi.org/10.13031/aea.13909.

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Анотація:
HighlightsThe logic used in developing a decision support system for irrigating peanut based on max/min soil temperature is describedLogic to transform decision support system from peanut to irrigate corn and cotton with and without soil sensors.Progression of a decision support system from a desktop program to a web/mobile applicationAbstract. Irrigator Pro is a decision support tool for scheduling irrigation events in peanut. It was deployed in 1995 as a rule-based system using crop history, yield potential, soil type, in-season irrigation/rainfall and maximum/minimum soil temperature. As computing platforms have progressed from desktop personal computers to mobile web-based platforms, Irrigator Pro has been updated and is now deployed as a web-based program and an application for mobile devices. Irrigator Pro not only works for peanuts but has been modified to irrigate both corn and cotton. The irrigation decisions are now based on in-field soil water potential measurements in addition to the traditional checkbook with max/min soil temperatures. Users are individual growers, extension agents, and agronomic consultants. The objective of this manuscript is to document the initial development of Irrigator Pro as an expert system combining data and experiential knowledge and the progression from a checkbook-based decision support system to a hybrid system using observed weather data and soil moisture measurement. The background knowledge, equations, and thresholds for triggering irrigation recommendations are included. Keywords: Decision support system, Irrigation scheduling, Irrigator Pro, Mobile app, Peanut, Soil water potential.
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2

Bethune, M. G., and T. J. Batey. "Impact on soil hydraulic properties resulting from irrigating saline–sodic soils with low salinity water." Australian Journal of Experimental Agriculture 42, no. 3 (2002): 273. http://dx.doi.org/10.1071/ea00142.

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Irrigation-induced salinity is a serious problem facing irrigated areas in the Murray–Darling Basin of Australia. Groundwater pumping with farm re-use for irrigation is a key strategy for controlling salinity in these irrigation areas. However, the re-use of highly saline–sodic groundwater for irrigation leads to accumulation of sodium in the soil profile and can result in sodic soils. Leaching of saline–sodic soils by winter rainfall and low salinity irrigation waters are 2 management scenarios likely to exacerbate sodicity problems. Characteristic to sodic soils is poor soil structure and potentially reduced soil permeability. Two indicators of soil permeability are infiltration rate and hydraulic conductivity. A replicated plot experiment was conducted to examine the long-term impact of irrigation with saline–sodic water on soil permeability. High levels of soil sodicity (ESP up to 45%) resulted from 10 years of saline irrigation. Over this period, leaching by winter rainfall did not result in long-term impacts on soil hydraulic properties. Measured soil hydraulic properties increased linearly with the salinity of the applied irrigation water. Leaching by irrigating with low salinity water for 13 months decreased soil salinity and sodicity in the topsoil. The resulting reduction in steady-state infiltration indicates soil structural decline of the topsoil. This trial shows that groundwater re-use on pasture will result in high sodium levels in the soil. Sodicity-related soil structural problems are unlikely to develop where there is consistent groundwater irrigation of pasture. However, structural decline of these soils is likely following the cessation of groundwater re-use.
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3

Bajwa, M. S., and A. S. Josan. "Effects of Alternating Sodic and Non-sodic Irrigations on the Build-up of Sodium in the Soil and on Crop Yields in Northern India." Experimental Agriculture 25, no. 2 (April 1989): 199–205. http://dx.doi.org/10.1017/s0014479700016707.

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SUMMARYIn a field experiment, the effects of irrigating crops alternately with sodic water (high in sodium adsorption ratio and ) and good quality canal water were investigated for six years on a well drained sandy loam (Typic Ustochrept). The irrigation treatments included: irrigation with non-sodic canal water (CW), irrigation with sodic water (SW), CW irrigation alternating with one or two SW irrigations, and two CW irrigations alternating with one SW irrigation. The results showed that the use of sodic water increased the sodium saturation of the soil and decreased rice and wheat yields. The build-up of sodium depended on the number of SW irrigations during the season. The increase in sodium saturation and decline in crop yields were progressive over the years. The improvements in yield due to alternating sodic and non-sodic irrigations compared with the use of sodic water alone increased over the years. Alternating sodic and non-sodic irrigations could therefore be considered a practical way to alleviate the problems caused by sodic water. The number of sodic irrigations during a season should, however, be kept to a minimum and the build-up of sodium in the soil over time should be monitored.
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4

Zhang, Yu, Yongjun Zhu, and Baolin Yao. "A study on interannual change features of soil salinity of cotton field with drip irrigation under mulch in Southern Xinjiang." PLOS ONE 15, no. 12 (December 30, 2020): e0244404. http://dx.doi.org/10.1371/journal.pone.0244404.

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The drip irrigation under mulch has become one of significant supporting technologies for cotton industry development in Xinjiang, and has shown the good economic and ecological benefits. With the rapid development of society and economy in Southern Xinjiang, the conventional mode of large-quota winter and spring irrigation, salt leaching and alkali decreasing is difficult to support sustainable development of land and water resources in Southern Xinjiang. This study tries to adjust soil moisture and salt content regulation mode of massive water salt leaching and drip irrigation under mulch in the non-growing period of cotton field in Southern Xinjiang, explores interannual soil salinity change features of drip irrigation cotton field without winter and spring irrigation, and provides experimental basis for drip irrigation technology under mulch which can reduce and exempt cotton irrigation in winter and spring. According to ET0, the dual-factor complete combination experiment involving 3 irrigating water quotas (I1, I2, I3) and 2 irrigation times (T12, T16) was designed, and 6 treatments were involved in total(I1T12,I2T12,I3T12,I1T16,I2T16 and I3T16). The investigation results of four-year (2012–2015) field positioning experiment showed that, under the condition of “germination under drip irrigation” without winter and spring irrigation, increasing irrigation quota and irrigation times could lower 0-100cm soil salinity accumulation, but the soil salinity accumulation degree was 40-100cm, and less than 0-30cm. In the seedling stage, bud stage, blossom and boll-forming stage, and boll opening stage, the average salinity of 0-100cm soil increased by 39.81%, 31.91%, 26.85% and 29.47%, respectively. Increasing irrigation quota and irrigation times could ease interannual soil salinity accumulation degree of cotton field with drip irrigation under mulch, without winter and spring irrigation. 0-100cm soil salinity before sowing was related to the irrigation quota of cotton in the growing stage of the last year. The larger the irrigation quota was, the smaller the soil salinity before sowing would be. The accumulation amount of soil salinity at the end of growing stage under different treatments was lower than that before sowing. The drip irrigation of cotton under mulch in the growing stage could effectively regulate soil salinity distribution and space-time migration process in the growing stage of cotton. Compared with the beginning of 2012, 0-100cm average soil salinity under 3 irrigation quotas (I1, I2, I3) was 33.66%, 5.60% and 1.24%, respectively. Salt accumulating rates under 12 irrigations and 16 irrigations were 20.66% and 6.33%, respectively. The soil had the risk of salinization when the “germination under drip irrigation” without winter and spring irrigation was used. Such results can provide the reference for prevention and treatment of soil moisture and salt content of cotton field with drip irrigation under mulch in the arid region.
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5

Hanson, Blaine R., Donald M. May, and Larry J. Schwankl. "Effect of Irrigation Frequency on Subsurface Drip Irrigated Vegetables." HortTechnology 13, no. 1 (January 2003): 115–20. http://dx.doi.org/10.21273/horttech.13.1.0115.

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The effect on crop yield of drip-irrigation frequencies of two irrigations per day (2/d), one irrigation per day (1/d), two irrigations per week (2/week), and one irrigation per week (1/week) was investigated for lettuce (Lactuca sativa), pepper (Capsicum annuum), and onion (Allium cepa) grown on sandy loam and processing tomato (Lycopersicon esculentum) grown on silt loam during experiments conducted during 1994 to 1997. All treatments of a particular crop received the same amount of irrigation water per week. Results showed that the 1/week frequency should be avoided for the shallow rooted crops in sandy soil. Irrigation frequency had little effect on yield of tomato, a relatively deep-rooted crop. These results suggest that drip irrigation frequencies of 1/d or 2/week are appropriate in medium to fine texture soils for the soil and climate of the project site. There was no yield benefit of multiple irrigations per day.
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6

Sui, Ruixiu, and Earl D. Vories. "Comparison of Sensor-Based and Weather-Based Irrigation Scheduling." Applied Engineering in Agriculture 36, no. 3 (2020): 375–86. http://dx.doi.org/10.13031/aea.13678.

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HighlightsSensor-based irrigation scheduling methods (SBISM) were compared with computerized water balance scheduling.Number and time of irrigation events scheduled using the SBISM were often different from those predicted by the computerized method.The highly variable soils at the Missouri site complicated interpretation of the sensor values.Both SBISM and computerized water balance scheduling could be used for irrigation scheduling with close attention to soil texture and effective rainfall or irrigation.Abstract. Sensor-based irrigation scheduling methods (SBISM) measure soil moisture to allow scheduling of irrigation events based on the soil-water status. With rapid development of soil moisture sensors, more producers have become interested in SBISM, but interpretation of the sensor data is often difficult. Computer-based methods attempt to estimate soil water content and the Arkansas Irrigation Scheduler (AIS) is one example of a weather-based irrigation scheduling tool that has been used in the Mid-South for many years. To aid producers and consultants interested in learning more about irrigation scheduling, field studies were conducted for two years in Mississippi and a year in Missouri to compare SBISM with the AIS. Soil moisture sensors (Decagon GS-1, Acclima TDR-315, Watermark 200SS) were installed in multiple locations of a soybean field (Mississippi) and cotton field (Missouri). Soil water contents of the fields were measured hourly at multiple depths during the growing seasons. The AIS was installed on a computer to estimate soil water content and the required data were obtained from nearby weather stations at both locations and manually entered in the program. In Mississippi, numbers and times of the irrigation events triggered by the SBISM were compared with those that would have been scheduled by the AIS. Results showed the number and time of irrigation events scheduled using the SBISM were often different from those predicted by the AIS, especially during the 2018 growing season. The highly variable soils at the Missouri site complicated the interpretation of the sensor values. While all of the sites were within the Tiptonville silt loam map unit, some of the measurements appeared to come from sandier soils. The AIS assumed more water entered the soil than the sensors indicated from both irrigations and rainfalls less than 25 mm. While the irrigation amounts were based on the pivot sprinkler chart, previous testing had confirmed the accuracy of the charts. Furthermore, the difference varied among sites, especially for rainfall large enough to cause runoff. The recommendations based on the Watermark sensors agreed fairly well with the AIS in July after the data from the sandiest site was omitted; however, the later irrigations called for by the AIS were not indicated by the sensors. Both the sensor-based irrigation scheduling method and the AIS could be used as tools for irrigation management in the Mid-South region, but with careful attention to soil texture and the effective portion of rainfall or irrigation. Keywords: Irrigation scheduling, Soil moisture sensor, Soil water content, Water management.
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7

Zhu, Yang, Sun, and Zhang. "Response of Water-Salt Migration to Brackish Water Irrigation with Different Irrigation Intervals and Sequences." Water 11, no. 10 (October 7, 2019): 2089. http://dx.doi.org/10.3390/w11102089.

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Establishing methods for scientific and rational use of brackish water resources is the key to farmland irrigation in the Yellow River Delta region of China. In this study, we conducted laboratory simulation experiments with soil columns and monitored the changes in water infiltration and salt distribution under eight irrigation treatments, including four intervals (0, 30, 60, and 90 min between irrigations) and two sequences (brackish-brackish-fresh water and brackish-fresh-brackish water). The results showed that the duration of water infiltration into the soil was higher under intermittent irrigation than continuous irrigation, with the highest value recorded at the 90-min irrigation interval. There was no significant difference in the mean soil water content between the brackish-brackish-fresh water (28.01–29.71%) and brackish-fresh-brackish water (28.85–29.98%) irrigation treatments. However, the mean soil desalination rate of the brackish-brackish-fresh irrigation treatment (42.51–46.83%) was higher than that of the brackish-fresh-brackish irrigation treatment (39.48–46.47%), and a much higher soil desalination rate was observed at the 90-min irrigation interval, compared with the other intervals. In conclusion, brackish-brackish-fresh water irrigation at longer time intervals (e.g., 90 min between irrigations) is conducive to reduce soil salt content in the surface soil in the study region.
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8

Feng, Jinping, Hongguang Liu, Gang Wang, Rumeng Tian, Minghai Cao, Zhentao Bai, and Tianming He. "Effect of Periodic Winter Irrigation on Salt Distribution Characteristics and Cotton Yield in Drip Irrigation under Plastic Film in Xinjiang." Water 13, no. 18 (September 16, 2021): 2545. http://dx.doi.org/10.3390/w13182545.

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Анотація:
Winter irrigation is an effective means of salt leaching, but the long-term effect on salinity is unclear. In 2008–2019, three different soil types of farmlands were selected as the study area by drip irrigation under film mulch combined with periodic winter irrigation in the non-growth period. The salinity of 0–150 cm as well as the survival rate and yield of cotton in the non-growth and growth periods were monitored, respectively. The mass fraction of soil salt decreased rapidly under winter irrigation, and then, the salt content in each observation layer increased with years of cultivation. After 10 years of application, the soil salt content basically stabilized at a low level. In 2008, the salinity of the 0–150 cm observation layer of loamy clay, loam, and sandy loam varied within 6–60, 10–65, and 4–22 g·kg−1; after four winter irrigations in 2019, corresponding values dropped below 5.74, 3, and 4.76 g·kg−1, respectively. The salinity returns rate of the different observation layers all exceeded 40%. The desalination rate of the different soils after four winter irrigations all exceeded 63.52%. Cotton survival rate and yield in different soils were directly proportional to each other. After the second winter irrigation, the survival rates on the different soils all exceeded 60%. The results of this study can provide technical support for the sustainable development of different types of soil, farmers’ income increase, and salinization land improvement.
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9

Schutte, Brian J., Nina Klypin, and Manoj K. Shukla. "Influence of Irrigation Timing on Disturbance-Induced Reductions in Soil Seedbank Density." Weed Science 64, no. 4 (December 2016): 613–23. http://dx.doi.org/10.1614/ws-d-15-00191.1.

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Studies suggest that disturbance-induced reductions in soil seedbank density are diminished by periods of water scarcity after soil disturbance; however, this hypothesis has yet to be tested. The objectives of this study were (1) to determine the effects of increasing time between soil disturbance and flood irrigation on disturbance-induced reductions in soil seedbank density, and (2) to identify specific soil moisture levels that cause seedbank reductions under flood irrigation. Weed species in this study were junglerice, Palmer amaranth, and yellow foxtail. For Objective 1, artificial seedbanks with known numbers of seeds were disturbed 10, 3, or 0 d prior to flood irrigations under field conditions. For Objective 2, seeds were buried in soil mesocosms that were hydrated to specific soil water potentials (flooded, 0 kPa, −30 kPa, −60 kPa, and −180 kPa) and placed in laboratory conditions favorable for germination. For both objectives, seeds were recovered to determine the percentages of buried seeds that survived the disturbance or moisture treatments. Results for the field study indicated that soil disturbances reduced seedbank persistence of Palmer amaranth but did not affect seedbank persistence of junglerice and yellow foxtail. Disturbance-induced reductions in seedbank density were greatest when soil was disturbed 0 and 3 d prior to flood irrigations. For the laboratory study, results showed that waterlogged soil was not required for seedbank losses because rates of seedbank persistence were greater in saturated soils (0 kPa and flooded) compared to the lower moisture levels. These studies indicate that delays in irrigation can reduce the seedbank reduction potentials of soil disturbance events. Further, irrigation timing effects on disturbed soil seedbanks are likely to occur in all irrigation systems, including those that reduce the amount of water applied compared to flood irrigation.
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Rengasamy, P., and KA Olsson. "Irrigation and sodicity." Soil Research 31, no. 6 (1993): 821. http://dx.doi.org/10.1071/sr9930821.

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The productivity of irrigated agriculture in Australia is low for most crops and one important factor is the physical and chemical constraints caused by sodicity in the rootzone. Over 80% of the irrigated soils are sodic and have degraded structure limiting water and gas transport and root growth. Irrigation, without appropriate drainage, leads to the buildup of salts in soil solutions with increased sodium adsorption ratio (SAR) and can develop perched watertables due to a very low leaching fraction of the soil layers exacerbated by sodicity. Therefore, irrigation management in Australia is closely linked with the management of soil sodicity.The inevitable consequence of continued irrigation of crops and pastures with saline-sodic water without careful management is the further sodification of soil layers and concentration of salt in the rootzone. This will increase the possibility of dissolving toxic elements from soil minerals. The yields of crops can be far below the potential yields determined by climate. The cost of continued use of amendments and fertilizers to maintain normal yields will increase under saline-sodic irrigation. Most of the irrigated soils in Australia need reclamation of sodicity of soil layers at least in the rootzone. The management of these sodic soils involves the application of gypsum, suitable tillage and the maintenance of structure by the buildup of organic matter and biological activity aver time. Then artificial drainage, an essential component of the management of irrigated sodic soils, is possible. By following these soil management practices, irrigated agriculture in Australia will become sustainable with increased yields and high economic returns.
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Дисертації з теми "Soil irrigation"

1

Martin, E. C., S. Husman, R. Wegener, P. Brown, K. Johnson, and L. Schnakenberg. "Determining Soil Moisture for Irrigation Management." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210311.

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One key component in good irrigation management is the measurement of soil moisture to help determine when to irrigate. In this study, resistance blocks and tensiometers were compared to neutron probe readings to assess how well these devices followed soil moisture and whether the resistance blocks and /or tensiometers could be used to schedule irrigation in cotton production. The resistance blocks were placed at 6, 18, and 30 inches. Tensiometers were placed at 18 and 30 inches. The readings from the resistance blocks and tensiometers were compared to neutron probe readings taken at 6, 18, and 30 inches. The resistance blocks compared well with the neutron probe readings at the 6 inch and 30 inch depth. At the 18 inch depth, there was much scatter in the data. The tensiometers also showed good comparisons at 30 inches and poor comparisons at 18 inches.
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2

Silvertooth, Jeffrey C. "Soil Management and Soil Testing for Irrigated Cotton Production." College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/558523.

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Анотація:
Reviewed 06/2015; Originally published: 02/2001
5 pp.
In this article we will discuss various aspects of soil evaluation including physical examination, soil sampling and analysis, and soil test interpretation. We will also discuss how these approaches to soil evaluation can be incorporated into both short- and long-term management plans.
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3

Geremew, Eticha Birdo. "Modelling the soil water balance to improve irrigation management of traditional irrigation schemes in Ethiopia." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-05242009-121531.

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Martin, Edward C. "Methods of Measuring for Irrigation Scheduling - WHEN." College of Agriculture, University of Arizona (Tucson, AZ), 2014. http://hdl.handle.net/10150/333138.

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Анотація:
Revised; Originally published: 2009
6 pp.
Proper irrigation management requires that growers assess their irrigation needs by taking measurements of various physical parameters. Some use sophisticated equipment while others use tried and true common sense approaches. Whichever method used, each has merits and limitations. In developing any irrigation management strategy, two questions are common: “When do I irrigate?” and “How much do I apply?” This bulletin deals with the WHEN.
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Martin, E. C., K. O. Adu-Tutu, W. B. McCloskey, S. H. Husman, P. Clay, and M. Ottman. "Reduced Tillage Effects on Irrigation Management in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/197914.

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Анотація:
Conservation or reduced tillage practices in cotton-based crop rotation systems were studied in field experiments initiated at Marana, Coolidge and Goodyear in 2001. Following barley cover and grain crops, soil and water management assessments were made during the 2002 cotton season at the three sites. Cover and grain crop residues and a lack of tillage prior to planting cotton or during the cotton season increased the infiltration of irrigation water into coarsetextured soils, slowed irrigation advance times, and increased the amount of irrigation water used at two of the three sites compared to conventional tillage treatments.
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Killen, Mark Albert. "A physically based analytical model to predict infiltration under surge irrigation." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184379.

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A significant advantage attributed to surge flow irrigation is that for the same volume of water applied the stream will advance farther along the furrow than with continuous flow. This potentially will reduce runoff and deep percolation which will improve uniformity and application efficiency where this advance phenomenon holds. The mechanism for improvement in advance time has generally been ascribed to surface sealing and surface layer consolidation. However, these phenomena do not satisfactorily explain improved advance times in sandy soils. Widely used infiltration equations which require the determination of empirical coefficients are unsatisfactory as predictors of infiltration conditions of intermittent wetting. The Green-Ampt model and a simple redistribution model are combined into an analytical model to predict infiltration under surge irrigation. The model results are compared to infiltration tests on soil columns of three soils of different soil textures. Also the model and the experimental results from the soil columns are compared to predictions made by two numerical solutions of the Richard's equation. One of the numerical models includes the effect of hysteresis by the use of Mualem's model to predict the variation of moisture content with potential, the other numerical model neglects the effect of hysteresis. A comparison of the analytical and the numerical models shows good agreement in their predictions for the soils and surge cycles tested. A comparison of predictions made by all three models shows good correlation to the experimental results. Although the number of tests done on the analytical model were limited it appears to be nearly as good a predictor of infiltration as the numerical models. The greatest strength of the analytical model is that while the numerical models took many hours to do a single run, the analytical model took only a few minutes. Both model and experimental results indicate that there was no reduction in infiltration rates or volumes infiltrated with intermittent as compared to continuous wetting. Thus the reduction in hydraulic gradient is not a factor in the reduced infiltration observed by others.
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Santos, Francisco Lucio dos Reis Borges Brito dos. "SOIL MOISTURE UNIFORMITY IN AN IRRIGATED FIELD." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275377.

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Nyawakira, Bernard 1955. "Evaluation of two furrow infiltration measuring methods and furrow spacings." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277171.

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Анотація:
The effect of furrow spacing on infiltration should be determined in order to properly design an irrigation system. The blocked furrow infiltrometer (BFI) and the flowing furrow infiltrometer (FFI) methods were investigated for this purpose in two areas upon a precision field furrow. Three irrigations were performed in each method. The initial and final soil moisture contents (before and after irrigation), the furrow cross-section (before and after irrigation), the inflow volume and the furrow water surface elevations (during irrigation) were measured in each test furrow. Cumulative infiltration and infiltration rates were determined for each irrigation. The results indicate that the FFI test furrows infiltrated more water than did the BFI test furrows for the same infiltration time. The infiltration rates were higher in the FFI test furrows than in the BFI test furrows until they approach the basic intake rate. The infiltration rates were also higher during the 0.90 m spacing tests than during the 1.80 m spacing tests. The 0.90 m spacing test furrows infiltrated more water than did the 1.80 m spacing test furrows.
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Harper, Samantha (Samantha E. ). "Real-time control of soil moisture for efficient irrigation." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111509.

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Анотація:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2017.
Cataloged from PDF version of thesis. Page 52 blank.
Includes bibliographical references (pages 31-34).
In the field of precision irrigation control, two classes of controllers have emerged - classical controllers and model based controllers. The most widely-used real-time closed-loop controller is a bang-bang controller that applies water at a predetermined rate, duration, and minimum soil moisture. Due to the ease of installation of soil moisture sensors, this technology has been installed around the world. There have been few studies on altering the controller used with this existing infrastructure. This thesis articulates a model for using a real-time proportional-integral-derivative (PID) controller to minimize water use using HYDRUS- 1D, a software package for simulating the one-dimensional movement of water, heat, and solutes in porous media, to simulate soil moisture. In a direct comparison between the two controllers, the PID controller uses less water. However, small violations of the target soil moisture and optimization of the PID parameters present the current barrier to implementation of this technology. Maintaining soil moisture at or above minimal depletion is critical to support crop health throughout a growing season. PID controllers offer a mid-point between the simplistic bang-bang controllers and the model based controllers that require large datasets, wireless network infrastructure, and robust computing systems. With proper calibration, PID controllers can be implemented in the field with the same sensors that are widely used with bang-bang controllers resulting in a reduction of water use in regions where water is scarce.
by Samantha Harper.
M. Eng.
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Lordan, Sanahuja Joan. "Irrigation and soil management strategies to improve fruit tree response in limiting soil conditions." Doctoral thesis, Universitat de Lleida, 2015. http://hdl.handle.net/10803/289501.

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La transformació de terres marginals, juntament amb un augment dels processos de degradació del sòl (p. e. salinització) estan traslladant l'agricultura a sòls més desfavorables, fet que obliga al desenvolupament de noves estratègies de maneig dels cultius. Durant els últims anys s'han introduït noves estratègies de reg, com el reg localitzat enterrat (subsurface drip irrigation, SDI) o el reg deficitari controlat, tot i que resulta necessari avaluar la seva viabilitat i sostenibilitat quan són aplicades en sòls amb propietats físiques limitants. Alhora, l'ús d'esmenes orgàniques i les tècniques d’aeració forçada estan sorgint com a mètodes de recuperació de sòls a baix cost, que podrien millorar potencialment el rendiment dels cultius en situacions desfavorables. És important estudiar els efectes d'aquestes estratègies i tècniques sobre les propietats del sòl, així com en la fisiologia dels cultius i la seva productivitat, tot i que també sobre paràmetres de qualitat d'importància creixent en el sector fructícola, com el potencial de conservació de la fruita. L'objectiu general d'aquesta tesi ha estat el d'avaluar diferents estratègies de maneig del sòl i de reg, i estudiar els seus efectes en plantacions de presseguer i nectarina en sòls amb condicions físiques limitants.
La transformación de tierras marginales, junto con un aumento de los procesos de degradación del suelo (p. ej. salinización) están trasladando la agricultura a suelos más desfavorables, lo que obliga al desarrollo de nuevas estrategias de manejo de los cultivos. Durante los últimos años se han introducido nuevas estrategias de riego, como el riego localizado enterrado (subsurface drip irrigation, SDI) o el riego deficitario controlado, a pesar de que resulta necesario evaluar su viabilidad y sostenibilidad cuando son aplicadas en suelos con propiedades físicas limitantes. Al mismo tiempo, el uso de enmiendas orgánicas y las técnicas de aireación forzada están surgiendo como métodos de recuperación de suelos a bajo coste, que podrían mejorar potencialmente el rendimiento de los cultivos en situaciones desfavorables. Es de suma importancia el estudiar los efectos de estas estrategias y técnicas sobre las propiedades del suelo, así como en la fisiología de los cultivos y su productividad, aunque también sobre parámetros de calidad de importancia creciente en el sector frutícola, como el potencial de conservación de la fruta. El objetivo general de esta tesis fue el de evaluar diferentes estrategias de manejo de suelo y riego, y estudiar sus efectos en plantaciones de melocotón y nectarina en suelos con condiciones físicas limitantes.
Transformation of marginal land along with an increase of soil degradation processes (e.g. salinization) is moving the agriculture into more unfavorable soils, forcing the development of new management strategies. Subsurface drip irrigation (SDI) and deficit irrigation strategies have been widely studied although it is necessary to evaluate their feasibility and sustainability when applied in soils with limiting physical properties. At the same time, organic soil amendments and oxygation techniques are arising as low-cost soil reclamation methods that could potentially improve the crop performance under such situations. It is of paramount importance to study the effects of these strategies and techniques on soil properties as well as on crop physiology and productivity, but also on some quality parameters of growing importance in the fruit sector, such as fruit storability. The general aim of this thesis was to assess various soil management and irrigation strategies and study their effects on peach and nectarine orchards under limiting soil conditions.
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Книги з теми "Soil irrigation"

1

Lee, Teang Shui. Water quality, soil and managing irrigation of crops. Rijeka, Croatia: InTech, 2012.

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2

Aore, W. W. Irrigation suitability of the soils of the proposed extensions of Narosura and Kanunga Irrigation Schemes (Narok District). [Nairobi]: Republic of Kenya, Ministry of Agriculture and Livestock Development, National Agricultural Laboratories, Kenya Soil Survey, 1985.

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3

Fedorovich, Zhabin Viktor, and Khachaturʹi͡an Vadim Khat͡skovich, eds. Hydrogeological studies in soil percolation and land reclamation. New York: Gordon and Breach Science Publishers, 1985.

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4

Chiang, Shan-hsin. Two-dimensional infiltration equations: Soil-box laboratory experiments. Honolulu: University of Hawaii at Manoa, Water Resources Research Center, 1985.

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5

Chiang, Shan-hsin. Two-dimensional infiltration equations: Soil-box laboratory experiments. Honolulu: University of Hawaii at Manoa, Water Resources Research Center, 1985.

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6

McCarty, Lambert B., Lewis Ray Hubbard,, and Virgil Quisenberry. Applied Soil Physical Properties, Drainage, and Irrigation Strategies. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-24226-2.

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7

Singh, N. T. Irrigation and soil salinity in the Indian subcontinent: Past and present. Bethlehem: Lehigh University Press, 2005.

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8

Simmons, J. V. Preliminary studies of dispersive soil fabrics from the Burdekin River irrigation area, using the scanning electron microscope. Townsville, Qld: James Cook University of North Queensland, Dept. of Civil and Systems Engineering, 1989.

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9

Kaddous, Farid G. A. Recycling of secondary treated effluent through vegetable and a loamy sand soil. [Melbourne: Victoria] Dept. of Agriculture and Rural Affairs, 1986.

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10

Frenken, Karen. Irrigation potential in Africa: A basin approach. Rome: Food and Agriculture Organization of the United Nations, 1997.

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Частини книг з теми "Soil irrigation"

1

Chesworth, Ward, Augusto Perez‐Alberti, Emmanuelle Arnaud, H. J. Morel‐Seytoux, H. J. Morel‐Seytoux, U. Schwertmann, and Ernest Rawitz. "Irrigation." In Encyclopedia of Soil Science, 369–79. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-3995-9_304.

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2

Dasberg, Samuel, and Dani Or. "Soil Water and Salt Regime." In Drip Irrigation, 36–69. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-662-03963-2_3.

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3

Waller, Peter, and Muluneh Yitayew. "Soil Physics." In Irrigation and Drainage Engineering, 33–50. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-05699-9_3.

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4

Letey, John, L. H. Stolzy, and W. D. Kemper. "Soil Aeration." In Irrigation of Agricultural Lands, 941–49. Madison, WI, USA: American Society of Agronomy, 2015. http://dx.doi.org/10.2134/agronmonogr11.c52.

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Waller, Peter, and Muluneh Yitayew. "Modeling Soil Moisture." In Irrigation and Drainage Engineering, 493–510. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-05699-9_28.

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6

Hillel, Daniel, Ademola K. Braimoh, and Paul L. G. Vlek. "Soil Degradation Under Irrigation." In Land Use and Soil Resources, 101–19. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6778-5_6.

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7

Clark, Francis E., and W. D. Kemper. "Microbial Activity in Relation to Soil Water and Soil Aeration." In Irrigation of Agricultural Lands, 472–80. Madison, WI, USA: American Society of Agronomy, 2015. http://dx.doi.org/10.2134/agronmonogr11.c26.

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8

Keller, Jack, and Ron D. Bliesner. "Soil-Water-Plant Relations." In Sprinkle and Trickle Irrigation, 28–41. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4757-1425-8_3.

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9

Day, Paul R., G. H. Bolt, and D. M. Anderson. "Nature of Soil Water." In Irrigation of Agricultural Lands, 191–208. Madison, WI, USA: American Society of Agronomy, 2015. http://dx.doi.org/10.2134/agronmonogr11.c12.

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10

Holmes, J. W., S. A. Taylor, and S. J. Richards. "Measurement of Soil Water." In Irrigation of Agricultural Lands, 275–303. Madison, WI, USA: American Society of Agronomy, 2015. http://dx.doi.org/10.2134/agronmonogr11.c16.

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Тези доповідей конференцій з теми "Soil irrigation"

1

"Soil Water." In Irrigation Systems Management. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2021. http://dx.doi.org/10.13031/ism.2021.2.

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2

Kozma, Z., T. Ács, and L. Koncsos. "Unsaturated zone modelling: the role of soil database classification." In SUSTAINABLE IRRIGATION 2014. Southampton, UK: WIT Press, 2014. http://dx.doi.org/10.2495/si140181.

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Al-Ghobari, H. M. "A comparison of water application uniformity for drip irrigation system above and below soil surface at various soil depths and scheduling techniques in arid region." In SUSTAINABLE IRRIGATION 2012. Southampton, UK: WIT Press, 2012. http://dx.doi.org/10.2495/si120271.

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Cassel S., F., and D. Zoldoske. "Assessing canal seepage and soil salinity using the electromagnetic remote sensing technology." In SUSTAINABLE IRRIGATION 2006. Southampton, UK: WIT Press, 2006. http://dx.doi.org/10.2495/si060071.

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Comegna, A., G. Severino, and A. Sommella. "Surface measurements of hydraulic properties in an irrigated soil using a disc permeameter." In SUSTAINABLE IRRIGATION 2006. Southampton, UK: WIT Press, 2006. http://dx.doi.org/10.2495/si060331.

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6

Theron, E., P. A. L. Le Roux, M. Hensley, and L. Van Rensburg. "Evaluation of the Aardvark constant head soil permeameter to predict saturated hydraulic conductivity." In SUSTAINABLE IRRIGATION 2010. Southampton, UK: WIT Press, 2010. http://dx.doi.org/10.2495/si100141.

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7

Reddy, G. Nithin, Mohammad Danish, Yadala Syam Babu, and G. Koperundevi. "Automatic Irrigation and Soil Quality Testing." In 2018 International Conference on Recent Innovations in Electrical, Electronics & Communication Engineering (ICRIEECE). IEEE, 2018. http://dx.doi.org/10.1109/icrieece44171.2018.9009114.

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8

"A new soil water retention technology for irrigated highly permeable soils." In 2015 ASABE / IA Irrigation Symposium: Emerging Technologies for Sustainable Irrigation - A Tribute to the Career of Terry Howell, Sr. Conference Proceedings. American Society of Agricultural and Biological Engineers, 2015. http://dx.doi.org/10.13031/irrig.20152147252.

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9

May, D., and B. Hanson. "Is drip irrigation sustainable in the salt affected soil of the San Joaquin Valley of California?" In SUSTAINABLE IRRIGATION 2006. Southampton, UK: WIT Press, 2006. http://dx.doi.org/10.2495/si060081.

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10

Elsheikh, E. R. A., B. Schultz, A. M. Haili, and H. S. Adam. "Effect of deficit irrigation on yield and yield components of sunflower on Gezira clay soil, Sudan." In SUSTAINABLE IRRIGATION 2012. Southampton, UK: WIT Press, 2012. http://dx.doi.org/10.2495/si120321.

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Звіти організацій з теми "Soil irrigation"

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Tsur, Yacov, David Zilberman, Uri Shani, Amos Zemel, and David Sunding. Dynamic intraseasonal irrigation management under water scarcity, water quality, irrigation technology and environmental constraints. United States Department of Agriculture, March 2007. http://dx.doi.org/10.32747/2007.7696507.bard.

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In this project we studied optimal use and adoption of sophisticated irrigation technologies. The stated objectives in the original proposal were to develop a conceptual framework for analyzing intra-season timing of water application rates with implications for crop and irrigation technology selection. We proposed to base the analysis on an intra-seasonal, dynamic, agro-economic model of plants' water demand, paying special attention to contamination of groundwater and soil in intensively cultivated areas that increasingly rely on water of lesser quality. The framework developed in the project integrates (i) a bio-physical model of water flow in the vadose zone and water uptake by plants and yield response with (ii) a dynamic management model to determine the optimal intra-season irrigation policy. It consists of a dynamic optimization model to determine irrigation rates at each point of time during the growing season and aggregation relating harvested yield with accumulated water input. The detailed dynamic approach provides a description of yield production processes at the plant’s level, and serves to determine intra-season irrigation decisions. Data derived from extensive field experiments were used to calibrate the model's parameters. We use the framework to establish the substitution between irrigation technology (capital) and water inputs; this is an important property of irrigation water productivity that has been overlooked in the literature. Another important feature investigated is the possibility to substitute fresh and saline water with a minimal productivity loss. The effects of soil properties and crop characteristics on optimal technology adoption have also been studied. We find that sandy soil, with low water holding capacity, is more conducive to adoption of sophisticated drip irrigation, as compared to heavier soils in which drainage losses are significantly smaller.
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2

Minz, Dror, Stefan J. Green, Noa Sela, Yitzhak Hadar, Janet Jansson, and Steven Lindow. Soil and rhizosphere microbiome response to treated waste water irrigation. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598153.bard.

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Research objectives : Identify genetic potential and community structure of soil and rhizosphere microbial community structure as affected by treated wastewater (TWW) irrigation. This objective was achieved through the examination soil and rhizosphere microbial communities of plants irrigated with fresh water (FW) and TWW. Genomic DNA extracted from soil and rhizosphere samples (Minz laboratory) was processed for DNA-based shotgun metagenome sequencing (Green laboratory). High-throughput bioinformatics was performed to compare both taxonomic and functional gene (and pathway) differences between sample types (treatment and location). Identify metabolic pathways induced or repressed by TWW irrigation. To accomplish this objective, shotgun metatranscriptome (RNA-based) sequencing was performed. Expressed genes and pathways were compared to identify significantly differentially expressed features between rhizosphere communities of plants irrigated with FW and TWW. Identify microbial gene functions and pathways affected by TWW irrigation*. To accomplish this objective, we will perform a metaproteome comparison between rhizosphere communities of plants irrigated with FW and TWW and selected soil microbial activities. Integration and evaluation of microbial community function in relation to its structure and genetic potential, and to infer the in situ physiology and function of microbial communities in soil and rhizospere under FW and TWW irrigation regimes. This objective is ongoing due to the need for extensive bioinformatics analysis. As a result of the capabilities of the new PI, we have also been characterizing the transcriptome of the plant roots as affected by the TWW irrigation and comparing the function of the plants to that of the microbiome. *This original objective was not achieved in the course of this study due to technical issues, especially the need to replace the American PIs during the project. However, the fact we were able to analyze more than one plant system as a result of the abilities of the new American PI strengthened the power of the conclusions derived from studies for the 1ˢᵗ and 2ⁿᵈ objectives. Background: As the world population grows, more urban waste is discharged to the environment, and fresh water sources are being polluted. Developing and industrial countries are increasing the use of wastewater and treated wastewater (TWW) for agriculture practice, thus turning the waste product into a valuable resource. Wastewater supplies a year- round reliable source of nutrient-rich water. Despite continuing enhancements in TWW quality, TWW irrigation can still result in unexplained and undesirable effects on crops. In part, these undesirable effects may be attributed to, among other factors, to the effects of TWW on the plant microbiome. Previous studies, including our own, have presented the TWW effect on soil microbial activity and community composition. To the best of our knowledge, however, no comprehensive study yet has been conducted on the microbial population associated BARD Report - Project 4662 Page 2 of 16 BARD Report - Project 4662 Page 3 of 16 with plant roots irrigated with TWW – a critical information gap. In this work, we characterize the effect of TWW irrigation on root-associated microbial community structure and function by using the most innovative tools available in analyzing bacterial community- a combination of microbial marker gene amplicon sequencing, microbial shotunmetagenomics (DNA-based total community and gene content characterization), microbial metatranscriptomics (RNA-based total community and gene content characterization), and plant host transcriptome response. At the core of this research, a mesocosm experiment was conducted to study and characterize the effect of TWW irrigation on tomato and lettuce plants. A focus of this study was on the plant roots, their associated microbial communities, and on the functional activities of plant root-associated microbial communities. We have found that TWW irrigation changes both the soil and root microbial community composition, and that the shift in the plant root microbiome associated with different irrigation was as significant as the changes caused by the plant host or soil type. The change in microbial community structure was accompanied by changes in the microbial community-wide functional potential (i.e., gene content of the entire microbial community, as determined through shotgun metagenome sequencing). The relative abundance of many genes was significantly different in TWW irrigated root microbiome relative to FW-irrigated root microbial communities. For example, the relative abundance of genes encoding for transporters increased in TWW-irrigated roots increased relative to FW-irrigated roots. Similarly, the relative abundance of genes linked to potassium efflux, respiratory systems and nitrogen metabolism were elevated in TWW irrigated roots when compared to FW-irrigated roots. The increased relative abundance of denitrifying genes in TWW systems relative FW systems, suggests that TWW-irrigated roots are more anaerobic compare to FW irrigated root. These gene functional data are consistent with geochemical measurements made from these systems. Specifically, the TWW irrigated soils had higher pH, total organic compound (TOC), sodium, potassium and electric conductivity values in comparison to FW soils. Thus, the root microbiome genetic functional potential can be correlated with pH, TOC and EC values and these factors must take part in the shaping the root microbiome. The expressed functions, as found by the metatranscriptome analysis, revealed many genes that increase in TWW-irrigated plant root microbial population relative to those in the FW-irrigated plants. The most substantial (and significant) were sodium-proton antiporters and Na(+)-translocatingNADH-quinoneoxidoreductase (NQR). The latter protein uses the cell respiratory machinery to harness redox force and convert the energy for efflux of sodium. As the roots and their microbiomes are exposed to the same environmental conditions, it was previously hypothesized that understanding the soil and rhizospheremicrobiome response will shed light on natural processes in these niches. This study demonstrate how newly available tools can better define complex processes and their downstream consequences, such as irrigation with water from different qualities, and to identify primary cues sensed by the plant host irrigated with TWW. From an agricultural perspective, many common practices are complicated processes with many ‘moving parts’, and are hard to characterize and predict. Multiple edaphic and microbial factors are involved, and these can react to many environmental cues. These complex systems are in turn affected by plant growth and exudation, and associated features such as irrigation, fertilization and use of pesticides. However, the combination of shotgun metagenomics, microbial shotgun metatranscriptomics, plant transcriptomics, and physical measurement of soil characteristics provides a mechanism for integrating data from highly complex agricultural systems to eventually provide for plant physiological response prediction and monitoring. BARD Report
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Dasberg, Shmuel, Jan W. Hopmans, Larry J. Schwankl, and Dani Or. Drip Irrigation Management by TDR Monitoring of Soil Water and Solute Distribution. United States Department of Agriculture, August 1993. http://dx.doi.org/10.32747/1993.7568095.bard.

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Drip irrigation has the potential of high water use efficiency, but actual water measurement is difficult because of the limited wetted volume. Two long-term experiments in orchards in Israel and in California and several field crop studies supported by this project have demonstrated the feasibility of precise monitoring of soil water distribution for drip irrigation in spite of the limited soil wetting. Time Domain Reflectometry (TDR) enables in situ measurement of soil water content of well defined small volumes. Several approaches were tried in monitoring the soil water balance in the field during drip irrigation. These also facilitated the estimation of water uptake: 1. The use of multilevel moisture probe TDR system. This approach proved to be of limited value because of the extremely small diameter of measurement. 2. The placement of 20 cm long TDR probes at predetermined distances from the drippers in citrus orchards. 3. Heavy instrumentation with neutron scattering access tubes and tensiometers of a single drip irrigated almond tree. 4. High resolution spatial and temporal measurements (0.1m x 0.1m grid) of water content by TDR in corn irrigated by surface and subsurface drip. The latter approach was accompanied by parametric modelling of water uptake intensity patterns by corn roots and superimposed with analytical solutions for water flow from point and line sources. All this lead to general and physically based suggestions for the placement of soil water sensors for scheduling drip irrigation.
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4

Agassi, Menahem, Michael J. Singer, Eyal Ben-Dor, Naftaly Goldshleger, Donald Rundquist, Dan Blumberg, and Yoram Benyamini. Developing Remote Sensing Based-Techniques for the Evaluation of Soil Infiltration Rate and Surface Roughness. United States Department of Agriculture, November 2001. http://dx.doi.org/10.32747/2001.7586479.bard.

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The objective of this one-year project was to show whether a significant correlation can be established between the decreasing infiltration rate of the soil, during simulated rainstorm, and a following increase in the reflectance of the crusting soil. The project was supposed to be conducted under laboratory conditions, using at least three types of soils from each country. The general goal of this work was to develop a method for measuring the soil infiltration rate in-situ, solely from the reflectance readings, using a spectrometer. Loss of rain and irrigation water from cultivated fields is a matter of great concern, especially in arid, semi-arid regions, e.g. much of Israel and vast area in US, where water is a limiting factor for crop production. A major reason for runoff of rain and overhead irrigation water is the structural crust that is generated over a bare soils surface during rainfall or overhead irrigation events and reduces its infiltration rate (IR), considerably. IR data is essential for predicting the amount of percolating rainwater and runoff. Available information on in situ infiltration rate and crust strength is necessary for the farmers to consider: when it is necessary to cultivate for breaking the soil crust, crust strength and seedlings emergence, precision farming, etc. To date, soil IR is measured in the laboratory and in small-scale field plots, using rainfall simulators. This method is tedious and consumes considerable resources. Therefore, an available, non-destructive-in situ methods for soil IR and soil crusting levels evaluations, are essential for the verification of infiltration and runoff models and the evaluation of the amount of available water in the soil. In this research, soil samples from the US and Israel were subjected to simulated rainstorms of increasing levels of cumulative energies, during which IR (crusting levels) were measured. The soils from the US were studied simultaneously in the US and in Israel in order to compare the effect of the methodology on the results. The soil surface reflectance was remotely measured, using laboratory and portable spectrometers in the VIS-NIR and SWIR spectral region (0.4-2.5mm). A correlation coefficient spectra in which the wavelength, consisting of the higher correlation, was selected to hold the highest linear correlation between the spectroscopy and the infiltration rate. There does not appear to be a single wavelength that will be best for all soils. The results with the six soils in both countries indeed showed that there is a significant correlation between the infiltration rate of crusted soils and their reflectance values. Regarding the wavelength with the highest correlation for each soil, it is likely that either a combined analysis with more then one wavelength or several "best" wavelengths will be found that will provide useful data on soil surface condition and infiltration rate. The product of this work will serve as a model for predicting infiltration rate and crusting levels solely from the reflectance readings. Developing the aforementioned methodologies will allow increased utilization of rain and irrigation water, reduced runoff, floods and soil erosion hazards, reduced seedlings emergence problems and increased plants stand and yields.
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Gatliff, E. G., and M. C. Negri. Root engineering for self-irrigation that exploits soil depth dimension for carbon sequestration. Office of Scientific and Technical Information (OSTI), July 2002. http://dx.doi.org/10.2172/964000.

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M., Devkota, Gupta R.K., Martius C., Lamers J.P.A., Sayre K.D., and Vlek P.L.G. Soil salinity management on raised beds with different furrow irrigation modes in salt-affected lands. Center for International Forestry Research (CIFOR), 2015. http://dx.doi.org/10.17528/cifor/005519.

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Banin, Amos, Joseph Stucki, and Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents: Field Cycles and Basic Mechanism. United States Department of Agriculture, July 2004. http://dx.doi.org/10.32747/2004.7695870.bard.

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Анотація:
The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.
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8

Gillor, Osnat, Stefan Wuertz, Karen Shapiro, Nirit Bernstein, Woutrina Miller, Patricia Conrad, and Moshe Herzberg. Science-Based Monitoring for Produce Safety: Comparing Indicators and Pathogens in Water, Soil, and Crops. United States Department of Agriculture, May 2013. http://dx.doi.org/10.32747/2013.7613884.bard.

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Анотація:
Using treated wastewater (TWW) for crop irrigation represents an important opportunity for ensuring adequate food production in light of growing freshwater scarcity worldwide. However, the environmentally sustainable approach of using TWW for irrigation can lead to contamination of produce with fecal pathogens that may remain in treated water. The overall goal of this research was to evaluate the correlation between the presence of fecal indicator bacteria (FIB) and that of a suite of human pathogens in TWW, the irrigated soil, and crops. Field experiments were conducted to compare secondary and tertiary TWW with dechlorinated tap water for irrigation of tomatoes, a typical commercial crop, in Israel, a semi-arid country. Human pathogens including bacteria (Salmonella), protozoa (Cryptosporidiumand Giardia), and viruses (Adenovirus [AV Types A, B, C & 40/41] and Enterovirus [EV71 subtypes]) were monitored in two field trials using a combination of microscopic, cultivation-based, and molecular (qPCR) techniques. Results from the field trials indicate that microbial contamination on the surface of tomatoes did not appear to be associated with the source of irrigated waters; FIB contamination was not statistically different on tomatoes irrigated with TWW as compared to tomatoes irrigated with potable water. In fact, Indicator bacteria testing did not predict the presence of pathogens in any of the matrices tested. High concentrations of FIB were detected in water and on tomato surfaces from all irrigation treatment schemes, while pathogen contamination on tomato surfaces (Cryptosporidiumand Salmonella) was only detected on crops irrigated with TWW. These results suggest that regular monitoring for pathogens should take place to accurately detect presence of harmful microorganisms that could threaten consumer safety. A notable result from our study is that the large numbers of FIB in the water did not appear to lead to FIB accumulation in the soil. With the exception of two samples, E. coli that was present at 10³ to 10⁴ cells/100 mL in the water, was not detected in the soil. Other bacterial targets associated with the enteric environment (e. g., Proteusspp.) as well as protozoal pathogens were detected in the TWW, but not in the soil. These findings suggest that significant microbial transfer to the soil from TWW did not occur in this study. The pattern of FIB contamination on the surfaces of tomatoes was the same for all treatment types, and showed a temporal effect with more contamination detected as the duration of the field trial increased. An important observation revealed that water quality dramatically deteriorated between the time of its release from the wastewater treatment plant and the time it was utilized for irrigation, highlighting the importance of performing water quality testing throughout the growing season at the cultivation site.
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9

Graber, Ellen R., Linda S. Lee, and M. Borisover. An Inquiry into the Phenomenon of Enhanced Transport of Pesticides Caused by Effluents. United States Department of Agriculture, July 1995. http://dx.doi.org/10.32747/1995.7570559.bard.

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Анотація:
The objective of this collaborative research project was to determine the factors that may cause enhanced pesticide transport under effluent irrigation. For s-triazines, the potential for enhanced transport through association with effluent dissolved organic matter (OM) was shown to be small in batch and column studies and in numerical simulations. High alkalinity and pH of treated effluents increased soil-solution pH for selected soil-effluent combinations, promoting the dissolution of soil OM and mobilizing otherwise OM-retained pesticides. Evapotranspiration in column studies resulted in increased pore-water concentrations of dissolved OM and some pesticide transport enhancement with the greatest effect observed with OM-poor soils. For ionogenic pesticides, effluent-induced increases in soil-solution pH increased the mobility of pesticides with acid dissociation constants within 2 pH units of the initial soil-solution pH. Effluents high in suspended solids and/or monovalent cations resulted in blockage of soil pores reducing water-flow velocity and/or changing flow paths. Reduced flow resulted in an increase in desorption time of soil sorbed pesticides, increasing the amount available for further transport with the net effect being soil texture dependent. In terms of pesticide degradation in soils, effluents appeared to have only a minor effect for the few pesticides investigated.
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10

Miyamoto, Seiichi, and Rami Keren. Improving Efficiency of Reclamation of Sodium-Affected Soils. United States Department of Agriculture, December 2000. http://dx.doi.org/10.32747/2000.7570569.bard.

Повний текст джерела
Анотація:
Sodium affected soils, along with salt-affected soils, are distributed widely in irrigated areas of the arid and semi-arid region of the world. Some of these soils can and must be reclaimed to meet the increasing demand for food, and existing irrigated lands must be managed to reduce salinization and alkalization associated with deteriorating irrigation water quality. This project was conducted for examining ways to reduce the use of chemical amendments and large quantities of leaching water for reclaiming sodic soils or for preventing soil sodification, We hypothesized that sodicity of calcareous soils irrigated with moderately sodic irrigation water can be controlled by maximizing dissolution of soil CaCO3. The work performed in Israel has shown that dissolution of CaCO3 can be enhanced by elevating the CO2 partial pressure in soils, and by increasing pore water velocity. The concentration of Ca in pore water was at an order of 1.5 mmolc L-1 at a CO2 partial pressure of 5 kPa, which is sufficient to maintain SAR below 4 at salinity of irrigation water of 0.5 dS m-1 or less. Incorporation of crop residue at a flesh weight of 100 Mg ha-1 reduced the exchangeable Na percentage from 19 to 5%, while it remained 14% without crop residue application These findings indicate a possibility of preventing soil sodification with appropriate crop rotation and residue management without chemical amendments, provided that soils remain permeable. In the case of highly sodic soils, dissolution of CaCO3 alone is usually insufficient to maintain soil permeability during initial leaching. We examined the effect of salinity and sodicity on water infiltration, then developed a way to estimate the amendments required on the basis of water infiltration and drainage characteristics, rather than the traditional idea of reducing the exchangeable Na percentage to a pre-fixed value. Initial indications from soil column and lysimeter study are that the proposed method provides realistic estimates of amendment requirements. We further hypothesized that cultivation of salt-tolerant plants with water of elevated salinity can enhance reclamation of severely Na-affected soils primarily through improved water infiltration and increased dissolution of CaCO3 through respiration. An outdoor lysimeter experiment using two saline sodic Entisols sodded with saltgrass for two seasons did not necessarily support this hypothesis. While there was an evidence of increased removal of the exchangeable Na originally present in the soils, the final salinity and sodicity measured were lowest without sod, and highest when sodded. High transpiration rates, coupled with low permeability and/or inadequate leaching seemed to have offset the potential benefits of increased CaCO3 dissolution and subsequent removal of exchangeable Na. Although vegetative means of reclaiming sodic soils had been reported to be effective in sandy soils with sufficient permeability, additional study is needed for its use in saline sodic soils under the high evaporative demand. The use of cool season grass after initial salt leaching with CaCl2 should be explored. Results obtained from this project have several potential applications, which include the use of crop residues for maintaining sodium balance, the use of CaCl2 for initial leaching of poorly permeable clayey sodic soils, and appraisal of sodicity effects, and appropriate rates and types of amendments required for reclamation
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