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Karya, Endang Kantikowati, dan Rinda Febrianti. "PENGARUH SISTEM OLAH TANAH DAN PENGENDALIAN GULMA TERHADAP PERTUMBUHAN DAN HASIL TANAMAN JAGUNG MANIS (ZEA mays SACCHARATA STURT.) VARIETAS PARAGON." AGRO TATANEN | Jurnal Ilmiah Pertanian 3, no. 2 (July 2, 2021): 20–26. http://dx.doi.org/10.55222/agrotatanen.v3i2.536.
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The aim of this study was to determine the effect of the interaction between the tillage system and weed control on the growth and yield of maize (Zea mays saccharata Sturt.) Paragon variety. The experiment was carried out in Cibalong Village, Ciheulang Village, Ciparay District, Bandung Regency. The time of the experiment was carried out from September to December 2020. The study used an experimental method, with a Randomized Designated Separate Group with a factorial pattern consisting of 2 treatment factors, namely the tillage system and the weed control system. The tillage system consists of TOT (No Tillage), OTMin (Minimum Tillage), OTMax (Maximum Tillage), while the weed control system factors consist of g1 (No Weed Control) g2 (Physical Mechanical Weed Control) g3 (Physical Mechanical Weed Control) Weed Chemically). The results showed that there was no interaction effect between tillage system and weed control on all observed parameters.
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Ginting, Rajiv, Jonatan Ginting, and Erwin Harahap. "Growth and production of sweet corn (Zea mays saccarata sturt L) with soil treatment and number of seeds per planting hole." IOP Conference Series: Earth and Environmental Science 886, no. 1 (November 1, 2021): 012117. http://dx.doi.org/10.1088/1755-1315/886/1/012117.
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Abstract Sweet corn production in Indonesia from is volatile and unstable. Unoptimal production of sweet corn in North Sumatra is caused by land conditions, plant populations, pest and disease and level of soil fertility. Effective and efficient soil tillage, crop spacing and number of seeds will affect the physical properties of the soil and plant productivity. This study aims to observe the best planting and tillage methods for maize. This study used a split plot design which is repeated three times with two factors, i.e. 3 levels of number of seeds per planting hole and 3 levels of soil tillage. The results showed that the treatment of tillage and the number of seeds per planting hole give significant effect on the variables of plant height, stem diameter, and total production. The interaction of these two factors showed an influence on the parameters of sweet corn plant height. The treatment of 2 seed per planting hole and 1 time of soil tillage show the best productivity compared to other treatments.
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Lewis, David Bruce, Jason P. Kaye, Randa Jabbour, and Mary E. Barbercheck. "Labile carbon and other soil quality indicators in two tillage systems during transition to organic agriculture." Renewable Agriculture and Food Systems 26, no. 4 (April 20, 2011): 342–53. http://dx.doi.org/10.1017/s1742170511000147.
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AbstractWeed management is one of the primary challenges for producers transitioning from conventional to organic agriculture. Tillage and the use of cover crops are two weed control tactics available to farmers transitioning to organic management, but little is known about their interactive effects on soil quality during the transition period. We investigated the response of soils to tillage and initial cover crop during the 3-year transition to organic in a cover crop–soybean (Glycine max)–maize (Zea mays) rotation in the Mid-Atlantic region of the USA. The tillage treatment contrasted full, inversion tillage with moldboard plowing (FT) versus reduced tillage with chisel plowing (RT). The cover crop treatment contrasted annual versus mostly perennial species during the first year of the rotation. The experiment was initiated twice (Start 1 and Start 2), in consecutive years in adjacent fields. By the end of the experiment, labile carbon, electrical conductivity, pH and soil moisture were all greater under RT than under FT in both starts. Soil organic matter and several other soil attributes were greater under RT than under FT in Start 1, but not in Start 2, perhaps owing to differences between starts in initial field conditions and realized weather. Soil attributes did not differ between the two cover crop treatments. Combining our soils results with agronomic and economic analyses on these plots suggests that using RT during the organic transition can increase soil quality without compromising yield and profitability.
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Bečka, David, Lucie Bečková, Perla Kuchtová, Pavel Cihlář, Kateřina Pazderů, Vlastimil Mikšík, and Jan Vašák. "Growth and yield of winter oilseed rape under strip-tillage compared to conventional tillage." Plant, Soil and Environment 67, No. 2 (February 5, 2021): 85–91. http://dx.doi.org/10.17221/492/2020-pse.
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Three-year field trials were conducted to compare the effect of three tillage systems: strip-tillage (ST), strip-tillage after mouldboard ploughing (STmp) and conventional tillage (CT) on growth and yield of winter oilseed rape at the experimental station in Červený Újezd, Czech Republic. Compared to CT, the growth of roots and aboveground biomass was slower (significantly thinner root necks, shorter roots and leaves) under ST at the beginning of vegetation (BBCH 14–18). Plants under ST still had significantly thinner root necks, and a lower number of leaves than plants from CT before winter (BBCH 21) but the differences were no longer statistically significant in spring (BBCH 30). Despite a slower start, the ST variant with an average yield of 5.47 t/ha significantly exceeded the CT variant with the yield being 5.06 t/ha. Conversely, plants grown under STmp had significantly longer leaves than those under CT in BBCH 14–18 and with the highest values of all parameters, tended to faster growth of biomass, although the other differences were not statistically significant. No differences were observed between STmp and CT in BBCH 21 and 30. The STmp variant achieved the highest yield 5.53 t/ha, and significantly exceeded the CT variant.
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Jederlund, Ulf. "Tillit som förutsättning för skolutveckling. En studie av skolutveckling genom kollektivt lärande i arbetslag." Pedagogisk forskning i Sverige 24, no. 3-4 (October 28, 2019): 7–34. http://dx.doi.org/10.15626/pfs24.0304.01.
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Artikeln bidrar till fördjupad förståelse av lokala förutsättningar för skolutveckling genom kollektivt lärande i arbetslag. En longitudinell fallstudie genomfördes av skolutvecklingsprocesserna i fem arbetslag på olika skolor som deltog i ett identiskt, externt utformat, utvecklingsprojekt. Projektet innebar en handledd lärandeprocess där lärarna förväntades utveckla gemensam kunskap och kompetens genom kollektiv reflektion, baserad på synliggjord praktik i form av kollektivt planerade och genomförda elevinterventioner. Interventionerna bestod i kartläggning av skolsvårigheter, filmade samarbetsbaserade lärar-elevsamtal och uppföljningar av dessa, med anpassningar i undervisning och elevarbete. Utfallet av projektet, såsom skattat av lärarna efter två år, varierade stort mellan skolorna. Variationen i utfall, trots att arbetslagen deltagit på jämförbara premisser och med likvärdigt tillförda resurser, är artikelns utgångspunkt.
Intresset riktas mot lärarnas upplevelser i utvecklingsprocessen. Analysen bygger på kvalitativa processdata insamlade före, under och efter projektet. I tematisk analys urskildes tre aspekter av lärares upplevelser av tillit i skolutvecklingsprocessen som centrala; processtillit, kollegial tillit och kollektiv tillit. Övergripande processtillit och kollektiv tillit framstod som förutsättningar för arbetslagens uthållighet i utvecklingsarbetet. Kollegial tillit - tillitsfulla interpersonella relationer och professionellt förtroende lärarna emellan i arbetslaget - framstod som en särskild förutsättning för att lärares praktik skulle synliggöras, och att ett fördjupat kollektivt lärande därmed skulle kunna äga rum. Kollegial tillit och kollektiv tillit är begrepp som återfinns i organisationslitteraturen, medan processtillit är ett begrepp som artikeln förslår.
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Jabbour, Randa, Tara Pisani-Gareau, Richard G. Smith, Christina Mullen, and Mary Barbercheck. "Cover crop and tillage intensities alter ground-dwelling arthropod communities during the transition to organic production." Renewable Agriculture and Food Systems 31, no. 4 (August 12, 2015): 361–74. http://dx.doi.org/10.1017/s1742170515000290.
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AbstractWe conducted a cropping systems experiment in central Pennsylvania, USA, to determine the effects of initial cover crop species and soil management on the abundance and composition of the ground-dwelling arthropod community. We hypothesized that we would detect legacy effects of the cover crops planted in year 1 of a 3-yr crop sequence on the arthropod community in the subsequent 2 yrs, and that these effects would be influenced by the intensity of tillage. We compared four systems in a factorial combination of perennial sod and legumes or annual cereal grain and legume as initial cover crops and moldboard or chisel plow tillage implemented in soybeans followed by maize in the subsequent 2 yrs. The entire experiment was initiated twice in adjacent locations, starting in 2003 (Start 1) and 2004 (Start 2). We quantified soil arthropod activity-density and community composition and identified all arthropods to order or family, and the ground and tiger beetles (Coleoptera: Carabidae) to species. In Start 1, but not Start 2, arthropod activity-density increased with each year following implementation of organic management. We observed few legacy effects of cover crop or tillage intensity on arthropod activity-density. The composition of the soil arthropod community was primarily defined by the initial cover crop in the first year, and by the interaction between cover crop and tillage intensity in the second and third year. A legacy effect associated with a yr-1 cover crop of cereal rye was observed for Scarabaeidae beetles and Formicidae (ants) in yr 2 and Carabidae beetles in yr 3 of Start 1, but not Start 2. Weed indicators contributed significantly to the variation in the soil arthropod community that was explained by the environment in yr 2 in Start 1, and in yr 3 in both Starts. Our observations support the concept that both immediate and legacy effects of management shape arthropod communities during the organic transition period, suggesting that transitioning systems could be managed in ways that conserve or enhance natural enemy populations.
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Ustinov, Nikolay, Vitaly Mikhailov, and Felix Bulatov. "Experimental study of the S-shaped load element of the soil tillage machine." АгроЭкоИнфо 7, Special (November 24, 2021): 9. http://dx.doi.org/10.51419/20217009.
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This article discusses the design of the strut of a tillage machine in the form of an S-shaped power element, using flexible tubular elements (Bourdon springs). Racks of this type are proposed for copying the soil microrelief, maintaining the depth of soil cultivation using a hydraulic drive. The possibility of using the S-shaped rack of the tool of the tillage machine, using flexible tubular elements, to ensure the copying of the soil micro-relief, compliance with the specified working depth, has been experimentally proved. Evaluation of the sensitivity and traction capacity of the S-shaped load-bearing element of the rack will allow us to speak of the ability to create displacements within 120 mm and traction forces up to 1600 N, at a maximum pressure of 6 MPa. Keywords: SOIL TILLAGE, TOOL TILLAGE, FLEXIBLE TUBULAR ELEMENT, DEPTH OF SOIL TILLAGE
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Walter, Gregory. "Berliner Vorlesungen I (1919-1920) - By Paul Tillich. Edited by Erdmann Sturm." Religious Studies Review 37, no. 2 (June 2011): 120–21. http://dx.doi.org/10.1111/j.1748-0922.2011.01509_40.x.
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Walter, Gregory. "Berliner Vorlesungen II (1920-1924) - By Paul Tillich. Edited by Erdmann Sturm." Religious Studies Review 37, no. 2 (June 2011): 121. http://dx.doi.org/10.1111/j.1748-0922.2011.01509_41.x.
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Walter, Gregory. "Berliner Vorlesungen III (1951-1958) - By Paul Tillich. Edited by Erdmann Sturm." Religious Studies Review 37, no. 2 (June 2011): 122. http://dx.doi.org/10.1111/j.1748-0922.2011.01509_44.x.
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Ruhaimah, Ruhaimah, Herviyanti Herviyanti, Adrinal Adrinal, and Giska Oktabriana. "PENGARUH PENGOLAHAN TANAH DAN PEMBERIAN MULSA ORGANIK TERHADAP PERUBAHAN BEBERAPA SIFAT KIMIA TANAH PSAMMENT DAN HASIL JAGUNG MANIS (Zea mays Saccharata Sturt)." Jurnal Solum 7, no. 2 (July 1, 2010): 124. http://dx.doi.org/10.25077/js.7.2.124-130.2010.
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A research about effect of soil managment and organic mulch application on soil physical properties of psamment and conr production was conducted in Korong Muaro, Nagari Sunur Kecamatan Nan Sabaris Kabupaten Padang Pariaman, as well as in soil laboratory, Agriculture Faculty, Andalas University Padang. This research was done from April – October 2009. The objective of the research was to identify interaction effect between soil cultivation and organic mulch application on chemical properties of psamment and production of sweet corn. This research was designed in two factors: 3 x 4 with three replications. The first factor was soil cultivation which consisted of 3 levels (Po = No-till, P1 = Minimum tillage, P2 = Conventional till). The second factor was organic mulch application, which consisted of four levels: Z = without mulch addition, T = Titonia for 8 ton DW/ha, K = Chromolaena for 8 ton DW/ha, J = straw 8 ton DW/ha. The result showed that soil cultivation combined with rice straw mulch application could increase N, P, K elements in soil. Soil N content increased from 0,17 % to 0,28 %, avail-P from 52,57 ppm to 88,60 ppm, and K-exch from 0,64 me/100g to 2,35 me/100g, however, minimum tillage gave the highest yield which was 7,68 ton weight of corn seeds + the stalk /hektar, and rice straw mulch showed the highest among the organic mulch applied, which was 8,85 ton/ha.Keywords: Soil cultivation, organic mulch, psamment, sweet corn
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Steponavičienė, Vaida, Vaclovas Bogužas, Aušra Sinkevičienė, Lina Skinulienė, Rimantas Vaisvalavičius, and Alfredas Sinkevičius. "Soil Water Capacity, Pore Size Distribution, and CO2 Emission in Different Soil Tillage Systems and Straw Retention." Plants 11, no. 5 (February 24, 2022): 614. http://dx.doi.org/10.3390/plants11050614.
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The long-term implementation of crop rotation and tillage has an impact on the soil environment through inputs and soil disturbance, which in turn has an impact on soil quality. Tillage has a long-term impact on the agroecosystems. Since 1999, a long-term field experiment has been carried out at the Experimental Station of Vytautas Magnus University. The aim of this experiment is to investigate the effects of long-term various-intensity tillage and straw retention systems on soil physical properties. The results were obtained in 2013 and 2019 (spring rape was growing). According to the latest edition of the International Soil Classification System, the soil in the experimental field was classified as Endocalcaric Stagnosol (Aric, Drainic, Ruptic, and Amphisiltic). The treatments were arranged using a split-plot design. In a two-factor field experiment, the straw was removed from one part of the experimental field, and the entire straw yield was chopped and spread at harvest in the other part of the field (Factor A). There were three different tillage systems as a subplot (conventional deep ploughing, cover cropping with following shallow termination, and no-tillage) (Factor B). There were four replications. The long-term application of reduced tillage significantly increased soil water retention and improved the pore structure and CO2 emissions. Irrespective of the incorporation of straw, it was found that as the amount of water available to plants increases, CO2 emissions from the soil increase to some extent and then start to decrease. Simplified tillage and no-tillage in uncultivated soil reduce CO2 emissions by increasing the amount of water available to plants from 0.151 to 0.233 m3·m−3.
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Walter, Gregory. "Dogmatik (Dresden 1925-1927) - By Paul Tillich. Edited by Werner Schussler and Erdmann Sturm." Religious Studies Review 37, no. 2 (June 2011): 121. http://dx.doi.org/10.1111/j.1748-0922.2011.01509_42.x.
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Tsuglenok, N. V., V. N. Romanov, and I. I. Katzer. "Study of various tillage technologies." IOP Conference Series: Earth and Environmental Science 981, no. 3 (February 1, 2022): 032038. http://dx.doi.org/10.1088/1755-1315/981/3/032038.
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Abstract At present, in the production of crop products, traditional energy-intensive (classical) methods of soil cultivation are used - plowing, disking, cultivation. At the time of the start of the development of this project, two patents were obtained: No. 2671480 dated October 31, 2018 and No. 2732021 dated September 10, 2020 on the technology of deep pin tillage. In the first version, the technology is implemented using a metal drum with a diameter of 2.5 and more meters with pins 25 or more centimeters long installed on its surface. A drum made on the principle of a wide bicycle wheel from 3 meters or more, is fixed by an axle on the frame, which clings to the tractor. The drum, rolling over the soil, under the action of its own weight under the action of the rotating spokes of the drum, which are endlessly rotating Archimedes levers, loosens spoilage with pins fixed on the outer surface of the drum. The larger the diameter of the drum and, accordingly, the spokes, the lower the energy consumption for loosening the soil and the greater the non-technological mass of such a unit. As a result of the continuation of the study of scientifically grounded ecological-geographical location and more efficient production of spring wheat in the forest-steppe conditions, to explain the possibilities of increasing yields up to 56 kg/ha.
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Busck, Ole. "Hvor blev medarbejderdeltagelsen i virksomhedernes miljøarbejde af?" Tidsskrift for Arbejdsliv 7, no. 4 (December 1, 2005): 27. http://dx.doi.org/10.7146/tfa.v7i4.108514.
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Selv om forskning har påvist et stort potentiale for organisationsudvikling og miljøforbedringer ved brug af medarbejderressourcen i virksomheder, er de fleste forsøg med deltagelse løbet ud i sandet eller afbrudt, og det synes småt med deltagelsen i dagens virksomheder. Uindfriede forventninger om humanisering af arbejdslivet og mere bæredygtighed i virksomheder gennem deltagelse står uforklarede. Artiklen søger gennem et overblik over forskningserfaringerne og de indvirkende samfundsmæssige vilkår at forklare paradokset og de udeblevne perspektiver. Forudsætninger og barrierer for aktivering af medarbejderpotentialet og deltagelse i organisatoriske forandringsprocesser søges identificeret tillige med betingelserne for organisatorisk og institutionel forankring af deltagelsen.
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Wang, Xiaoyan, Huanwen Gao, J. N. Tullberg, Hongwen Li, Nikolaus Kuhn, A. D. McHugh, and Yuxia Li. "Traffic and tillage effects on runoff and soil loss on the Loess Plateau of northern China." Soil Research 46, no. 8 (2008): 667. http://dx.doi.org/10.1071/sr08063.
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This paper reports the outcome of 5 years of field plot runoff monitoring, 2 years of water erosion measurement, and a rainfall simulation experiment on moderately sloping farmland on the loess plateau of north-west China. The objective was to test different conservation tillage systems compared with the control treatment, conventional mouldboard plough practice (CK). Tillage, residue cover, and compaction effects were assessed in terms of runoff and soil erosion. Results from the runoff plots showed that conservation tillage, with more residue cover, less compaction, and less soil disturbance, could substantially reduce runoff and soil erosion compared with the control. No tillage with residue cover and no compaction produced the least runoff and soil erosion. Compared with the control, it reduced runoff and soil erosion by about 40% and 80%, respectively. At the start of the experiment, residue cover appeared to be the most important factor affecting soil and water conservation, particularly when antecedent soil moisture was limited. With the accumulation of tractor wheeling effects over the course of the experiment, soil compaction appeared to become a more important factor affecting runoff. Rainfall simulation was then used to assess the effect of non-inverting surface tillage and different levels of residue cover and wheel compaction on infiltration and runoff. This confirmed that wheel compaction effects could be greater than those of tillage and residue cover, at least under the 82.5 mm/h rainfall rate produced by the simulator. The wheeling effect was particularly large when the treatment was applied to wet soil, and severe even after wheeling by small tractors.
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Chauhan, B. S., G. S. Gill, and C. Preston. "Tillage system effects on weed ecology, herbicide activity and persistence: a review." Australian Journal of Experimental Agriculture 46, no. 12 (2006): 1557. http://dx.doi.org/10.1071/ea05291.
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In the past few years, there has been a growing trend towards reducing tillage in cropping systems to allow stubble retention, earlier planting and improved soil structure. However, the adoption of conservation tillage systems will change weed control practices. Different tillage systems interact with the micro-environment of weed seeds and can influence the pattern of recruitment from the weed seed bank. Here, we present a review of the effect of different tillage systems on weed ecology, herbicide activity and herbicide persistence. Tillage systems can have a major influence on the vertical distribution of weed seeds in the soil seed bank. However, the impact of the changes in the vertical seed distribution on weed seedling recruitment is not well understood. Usually weed seedling recruitment increases if tillage equipment brings buried seed to, or close to, the soil surface, and seedling recruitment decreases if surface seed is buried deeper in the soil. However, tillage responses have a tendency to be species specific and can also be influenced by the intensity of tillage. Any weed species in which germination is stimulated by exposure to light is likely to become more prevalent under reduced tillage systems. Similarly, species that require burial for germination may become less prevalent. Crop residue present on the soil surface can also influence weed seedling recruitment by modifying the physical environment (mainly temperature) of weed seeds. Weed responses to plant residue could also be influenced by the allelopathic activity of the residue and the sensitivity of the weed species present. Few studies have investigated the fate of weed seeds that fail to germinate under any tillage system. Further research is needed to determine whether the weed seeds that fail to germinate decay before the start of the next growing season or become part of a persistent seed bank. Crop residues present on the soil surface can intercept a considerable amount of the applied herbicide and, depending on the herbicide, this intercepted component is susceptible to losses. Therefore, conservation tillage systems are expected to have lower efficacy of soil active herbicides. However, there has been little investigation of rate of loss of soil active herbicides under reduced tillage systems and the results reported have been inconsistent. Much of the research on these effects is from overseas and may not be true in Australian conditions. Therefore, further work is needed to clearly understand the impact of changing tillage systems on weed ecology, herbicide performance and persistence.
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Schmidt, Jan H., Maria R. Finckh, and Johannes Hallmann. "Oilseed radish/black oat subsidiary crops can help regulate plant-parasitic nematodes under non-inversion tillage in an organic wheat-potato rotation." Nematology 19, no. 10 (2017): 1135–46. http://dx.doi.org/10.1163/15685411-00003113.
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Soil conservation is one of the major challenges for agriculture in the 21st century. For this reason, non-inversion tillage systems including subsidiary crops have become popular over the last three decades in Europe. However, the adoption of new agricultural practices may change the diversity and abundance of certain pests and diseases. For example, plant-parasitic nematodes that are major threats towards cultivated plants may be promoted if good hosts, such as certain subsidiary crops and weeds, occur more frequently. The indigenous plant-parasitic nematode fauna under organic farming systems is already adapted to diverse crop rotations and usually dominated by nematodes with broad host ranges. These may be further enhanced in organic farming systems if non-inversion tillage is introduced, which generally increases the abundance and biomass of certain weeds. We evaluated the early effects of non-inversion tillage and subsidiary crops in an organic wheat-potato rotation on plant-parasitic nematodes in two field experiments in two successive years. The total densities of plant-parasitic nematodes increased from an initial 1260 nematodes (100 ml soil)−1 at the start of the experiment to 1850 and 1700 nematodes (100 ml soil)−1 after wheat under non-inversion and conventional tillage, respectively. Plant-parasitic nematode densities then decreased on average to 1100 and 560 nematodes (100 ml soil)−1 after subsidiary crops and potatoes, respectively. Parasitic nematode densities tended to be higher under non-inversion than conventional tillage, except where oilseed radish and black oats had been used as cover crops. For the latter, no differences between tillage treatments occurred. In the second experiment, about 1700 free-living nematodes (100 ml soil)−1 were found under conventional tillage without mulch while under reduced tillage with mulch their numbers were significantly higher at 3100 nematodes (100 ml soil)−1. We conclude that an appropriate choice of subsidiary crops can be an important management factor for the long term sustainability of non-inversion tillage systems.
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Ginting, J. "Effect of soil tillage methods and cattle fertilizer of cow on increasing sweet corn (Zea mays saccharate sturt) production." IOP Conference Series: Earth and Environmental Science 260 (June 7, 2019): 012176. http://dx.doi.org/10.1088/1755-1315/260/1/012176.
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Walter, Gregory. "Vorlesungen Uber Geschichtsphilosophie und Sozialpadagogik (Frankfurt 1929/30) - By Paul Tillich. Edited by Erdmann Sturm." Religious Studies Review 37, no. 2 (June 2011): 121. http://dx.doi.org/10.1111/j.1748-0922.2011.01509_43.x.
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Antonsson, Atli. "Eldrit á mannöld: Fjallið sem yppti öxlum eftir Gísla Pálsson og bókmenntir á tímum loftslagsbreytinga." Ritið 19, no. 3 (December 2019): 171–98. http://dx.doi.org/10.33112/ritid.19.3.8.
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Í bók sinni Fjallið sem yppti öxlum blandar mannfræðingurinn Gísli Pálsson saman minningum af uppvexti sínum í Heimaey, frásögnum af eldgosinu sem ógnaði eynni árið 1973 og umfjöllun um mannöldina. Í þessari grein er bókin greind með tilliti til þeirrar hugmyndar höfundarins að verkið tilheyri líklega nýrri bókmenntagrein mannaldar og atrenna er gerð að því að álykta um einkenni þessarar nýju bókmenntagreinar. Hugtakið mannöld er útskýrt og stutt yfirlit gefið yfir þær bókmenntir sem tengjast þessu nýja skeiði jarðsögunnar til að staðsetja bók Gísla Páls-sonar innan þess samhengis. Því næst er verkið skoðað með hliðsjón af hefðbundnari bókmenntagreinum: sjálfsævisögunni og svokölluðum eldritum, og ályktað að nýtt hugmyndafræðilegt samhengi gefi verkinu ákveðna sérstöðu innan þessara greina.
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Al-Wosabi, Mohammed A., and Sa’ad Z. Al-Mashaikie. "Investigation of Facies Types and Associations of Kuhlan Red Bed Formation in NW Yemen: A New Hypothesis for Origin and Depositional Environment." Sultan Qaboos University Journal for Science [SQUJS] 11 (June 1, 2006): 11. http://dx.doi.org/10.24200/squjs.vol11iss0pp11-38.
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Varieties of thirteen facies types were recognized in the Kuhlan Formation represented by red bed siliciclastic sequences of argillaceous sediments. Examination of the Kuhlan stratigraphic column included sequence relationships, lithology, sedimentary characters, structures and petrography of the dominant rock types. These facies types are grouped in three distinct associations of facies. The lower unit A comprises association of facies (Distal turbidites) represented by alternates of turbidity sequences including sandstone, siltstone and thick shale beds. These facies types confirm a regressive depositional environment in deep marine shelf conditions. There are three facies types which are identified as massive sandstone, cross-bedded sandstone and pebbly sandstone facies. The middle unit B association of facies (Proximal turbedites) represents glaciomarine sequences displaying high lateral and vertical facies changes of glacioturbidite sediment alternates with diamictites and tillite beds. The sequences are affected by eustatic and eustatism of the glacial advance and retreat. This unit B includes eight types of facies. These are identified as; tillite, massive diamictites, stratified diamictites, laminated siltstone/shale, deformed siltstone/mudstone, graded rhythmic siltstone, massive conglomerate and cross-stratified sandy conglomerate facies. The upper unit C association of facies is represented by shallow marine shelf sequences displaying very thick massive and locally cross-bedded sand bar sandstone overlying the laminated siltstone/shale interbeds. The upward gradual changes in mineralogical composition and color confirms the start of marine transgression and later deposited platform Amran Group. Mineralogical composition of Kuhlan sandstone displays impure dirty rocks consisting of more than 30% of argillaceous matrix, 50% of cristobalite and quartz grains, more than 10% of ferruginous cement and 10% of detrital iron oxide grains, potash feldspar, igneous rock fragments and carbonate cement. It is classified as quartz greywacke type in the lower and middle parts and as quartz arenite with subarkoses in the upper part.
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Crisnapati, Padma Nyoman, and Dechrit Maneetham. "Two-Dimensional Path Planning Platform for Autonomous Walk behind Hand Tractor." Agriculture 12, no. 12 (November 29, 2022): 2051. http://dx.doi.org/10.3390/agriculture12122051.
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The use of autonomous vehicles in agriculture has increased in recent years. To fully automate agricultural missions, particularly the tillage process using the walk-behind hand tractor, the path planning problem for the robot must be solved so that all points in the intended region of interest may be traced. The current planning algorithm has been successful in determining the best tillage path. On the other hand, the algorithm ignores the path built using the dynamic starting point, finish point and path distance. We propose a path planning concept for back-and-forth path patterns. Our algorithm employs a novel approach based on Laravel and Google Maps, which considers the user’s desired distance interval, start point, and finish point. We demonstrated auto-generating vertex-edge pathways in this research. Field trials using a walk-behind hand tractor in a plowing mission have been successfully conducted to validate the accuracy of the resulting waypoint coordinates.
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Simon, A. C. M., Horacio D. Lopez-Nicora, Terry L. Niblack, Elizabeth A. Dayton, David Tomashefski, and Pierce A. Paul. "Cropping Practices and Soil Properties Associated with Plant-Parasitic Nematodes in Corn Fields in Ohio." Plant Disease 102, no. 12 (December 2018): 2519–30. http://dx.doi.org/10.1094/pdis-03-18-0471-re.
Full textAbstract:
Ten morphological groups of plant-parasitic nematodes (spiral, lesion, lance, dagger, stunt, pin, ring, stubby-root, cyst, and miscellaneous tylenchids) were detected in corn fields in Ohio, but the presence and population density of these groups varied among fields. Binary and ordinal logistic regression models were fitted to the data to estimate the odds of each group being present, and the lesion, lance, spiral, and pin nematode population densities being at moderate-high risk levels based on soil region, cropping sequence, tillage, and soil pH, silt content, and electrical conductivity. All covariates were associated with at least one nematode group, but soil region had the greatest and most consistent effect. Dagger and ring nematodes were more likely to be present in region 6 than in any of the other regions, whereas lance, stunt, pin, stubby-root, and spiral nematodes were more likely to be present in regions 1 to 5 than 6. Spiral, lance, and pin nematode population densities were more likely to be at moderate-high risk levels in regions 3 and 4 than in region 6. Fields under conservation tillage were two times more likely to have moderate-high risk lance nematode population densities than fields under conventional tillage. Similarly, pin nematode population densities were two times more likely to be at moderate-high risk levels in fields under rotation than in continuous corn. For every unit increase in soil pH, the odds of the spiral nematode population density being at moderate-high risk levels increased by 43%, but the odds of the lesion and pin nematode population densities being at the same risk level decreased by 63 and 29%, respectively. The predicted probability of lesion and lance population densities being at moderate-high risk levels decreased as the silt content of the soil increased. These finding will be useful for developing future nematode sampling protocols and for assessing the risk associated with nematodes in corn fields in Ohio.
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Kirkegaard, Preben. "Danske folkebiblioteker under besættelsen." Bibliotekshistorie 6, no. 1 (July 10, 2002): 77–90. http://dx.doi.org/10.7146/bh.v6i1.35902.
Full textAbstract:
Det historiske tidsrum, der skal beskrives, er 1940-45, og vi kan yderligere præcisere det fra 9. april 1940 til 5. maj 1945. Da jeg er blevet bedt om at redegøre for mine personlige erfaringer fra folkebiblioteksarbejdet, ja, så lader stedet sig præcist lokalisere til Århus Folkebibliotek, som tillige var centralbibliotek og derfor betjente et stort landdistrikt med mange sognebiblioteker, for at være helt nøjagtig havde vi 66 selvstændige sognebiblioteker, og hertil kommer et antal udlånssteder, som vel bringer tallet op på hen ved 100 enheder. Århus havde 90.898 indbyggere og i biblioteket var indskrevet 14.949 voksne lånere, som lånte 361.172 bøger i løbet af det første krigsår, hvor budgettet var på 154.140 kr. og bogbestanden 49.147 bd. Da børne- og skolebiblioteker i disse år var selvstændige administrative enheder, udelukker jeg omtalen af deres arbejde.
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Nokleby, S. B., and R. P. Podhorodeski. "OPTIMIZATION-BASED SYNTHESIS OF A DEEP-DIGGING TILLAGE MECHANISM." Transactions of the Canadian Society for Mechanical Engineering 24, no. 1A (March 2000): 61–78. http://dx.doi.org/10.1139/tcsme-2000-0004.
Full textAbstract:
A quasi-Newton optimization method is employed to synthesize a four-bar tillage mechanism, a device for loosening the sub-soil in farm fields. The synthesis routine uses sequential parameter transformations that map from an unconstrained search variable space to a constrained design variable space. The sequential parameter transformations ensure that only a specific mechanism sub-type is considered, that Grashof criteria are satisfied, and that all mechanism parameters satisfy specified upper and lower constraints. Objective functions quantifying the level of satisfaction of the desired task displacements are minimized. It is shown that in addition to task satisfaction, further objective function terms can be added. The addition of objective function terms to increase the minimum transmission angle and to reduce the mechanism size are found to allow the synthesis of a practical mechanism for the deep-digging application. The use of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) method with Fletcher’s Line Search (FLS) algorithm has allowed for the development of an efficient optimization-based synthesis routine. The synthesis results demonstrate that the developed synthesis routine required on the order of 102 fewer iterations per start then the direct-search and Sequential Unconstrained Minimization Technique (SUMT) employed in a previous method.
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SIELING, K., O. GÜNTHER-BORSTEL, T. TEEBKEN, and H. HANUS. "Soil mineral N and N net mineralization during autumn and winter under an oilseed rape – winter wheat – winter barley rotation in different crop management systems." Journal of Agricultural Science 132, no. 2 (March 1999): 127–37. http://dx.doi.org/10.1017/s0021859698006273.
Full textAbstract:
Soil sampling in autumn gives important information on the soil N dynamic. In the growing seasons 1991/92 to 1995/96, the effects of different crop management systems on soil mineral N (NO3-N plus NH4-N:Nmin) were investigated in a factorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape – winter wheat – winter barley, and soil tillage (conservation tillage without ploughing, conventional tillage), application of pig slurry (none, autumn, autumn+spring), mineral N fertilization (0, 120 and 240 kg N ha−1) and fungicide application (none, three applications) were all varied. Each year, the treatments occurred in all three crops of the rotation and were located on the same plots. Nmin was determined on four dates (‘After drilling’, ‘End of autumn growth’ before winter, ‘Beginning of spring growth’ before N fertilizer application, and ‘After harvest’) to 90 cm in 30 cm horizons.Under all crops, Nmin showed a large year to year variation. Highest values of 132 kg N ha−1 were observed ‘After drilling’, which decreased until ‘End of growth’. The increase of autumn Nmin (‘After drilling’, ‘End of autumn growth’) was mainly due to autumn slurry, whereas mineral N fertilizer mainly affected Nmin ‘After harvest’. Soil tillage and fungicide application only slightly modified Nmin at all dates.The relationship between N leaching and Nmin measured either ‘After drilling’ or at the ‘End of autumn growth’ in 1991/92–1994/95 remained too poor to be used to estimate N leaching. N net mineralization during autumn and winter varied with crops, as estimated by the Nmin changes between ‘After drilling’ minus ‘Start of spring growth’ plus N uptake by the crop at ‘Start of spring growth’ plus N leaching during winter. On average over the years, 39 kg N ha−1 were mineralized under oilseed rape and 42 kg N ha−1 under wheat compared with 31 kg N ha−1 under barley. However, a large year-to-year variation occurred. In addition, the ranking of the years differed with the crops. Slurry application led to different amounts of mineralized N. Under barley only 25 kg N ha−1 were calculated for the autumn slurry, but 42 kg N ha−1 for the autumn plus spring slurry treatment. In contrast, under oilseed rape the highest value of 41 kg N ha−1 occurred in the autumn slurry plots. Under wheat, slurry application only slightly affected N mineralization. Increased mineral N fertilization decreased N release under oilseed rape, but significantly increased it under cereals. Application of fungicides did not affect N mineralization during winter.
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Peigné, Joséphine, Marion Casagrande, Vincent Payet, Christophe David, F. Xavier Sans, José M. Blanco-Moreno, Julia Cooper, et al. "How organic farmers practice conservation agriculture in Europe." Renewable Agriculture and Food Systems 31, no. 1 (January 20, 2015): 72–85. http://dx.doi.org/10.1017/s1742170514000477.
Full textAbstract:
AbstractThe interest of organic farmers in adopting conservation agriculture principles, including minimal soil disturbance, permanent soil cover and crop rotation has been growing since the early 2000s. However, currently there is no network for organic farmers practicing conservation agriculture, and a lack of knowledge on how organic farmers implement conservation agriculture in practice. Consequently, few technical references are available for organic farmers when they start applying conservation agriculture practices, in particular on controlling weeds without the use of herbicides. The main objectives of this study were: (1) to explore the diversity of conservation agriculture techniques (i.e., reduced tillage, no-tillage and green manures) practiced among European farmers, and (2) to identify farmers’ main strategies for implementing conservation agriculture and the agronomic and environmental factors that determine these strategies. Strategies were identified by analyzing survey results on: (1) the type and degree of use of conservation agriculture practices by farmers, and (2) the effects it produces in terms of soil disturbance and soil cover (low, medium and high). We carried out a survey of 159 European organic farmers and collected 125 data sets on management of winter-sown crops. Among the conservation agriculture practices, reduced tillage was used by 89%, no-tillage by 27% and green manure by 74% of the 159 interviewed farmers. Green manures were more frequently used in northern Europe than in the south (below 45°N). Most of the farmers used crop rotations, with a mean duration of 6 years. A wide diversity of conservation agriculture practices were used, with farmers rarely using all three techniques (no-till, reduced till and green manures) within one system. The range of practices was grouped into five strategies ranging from intensive non-inversion tillage without soil cover to very innovative techniques with no-tillage and intercrops. The five strategies for conservation agriculture could be grouped into two larger categories based on weed control approach: (1) intensification of the mechanical work without soil inversion or (2) biological regulation of weeds with cover crops. The diversity of strategies identified in this study shows that organic farmers use innovative approaches to implement conservation agriculture without herbicides. This study's findings will help organic farmers to experiment with innovative practices based on conservation agriculture principles and also benefit conventional farmers who use conservation agriculture practices and would like to reduce or eliminate the use of herbicides.
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Maher, Hassnae, Rachid Moussadek, Ahmed Ghanimi, Oumaima Zouidi, Ahmed Douaik, Houria Dakak, Nour Eddine Amenzou, and Abdelmjid Zouahri. "Effect of Tillage and Nitrogen Fertilization on Soil Properties and Yield of Five Durum Wheat Germoplasms in a Dry Area of Morocco." Applied Sciences 13, no. 2 (January 9, 2023): 910. http://dx.doi.org/10.3390/app13020910.
Full textAbstract:
In Morocco, cereal production is below the expected potential. The adoption of best agricultural practices that reduce vulnerability to climate is a major requirement. No-tillage (NT) agriculture is a system that could improve cereal production by enhancing soil fertility. Some factors, in combination with no-tillage, can further improve cereal yields, especially the choice of variety the adequate fertilization. The objective of our study is to investigate the effect of no-tillage agriculture and nitrogen fertilization on soil fertility and the yield of five durum wheat varieties developed in Morocco in a long-term (18 years) NT trial at the INRA Merchouch experimental station, Morocco. The results show that tillage type had a significant effect on soil organic carbon and CEC (measured before the start of the experiment), as well as on ammonium and nitrates (measured at the end of the experiment), whereas nitrogen dose had a significant effect on total nitrogen and nitrates (measured at the end of the experiment). Regarding wheat yield, as measured at the end of the experiment during the 2020–2021 cropping season, the results show that, under NT, the varieties Nachit, Faraj, and Louiza had grain yields of 4.5, 4.3, and 3.4 t ha−1 and straw yields of 9.8, 7.8, and 6.8 t ha−1, respectively, whereas the I.C and M.G germoplasms had grain yields of 4.05 and 3.72 t ha−1 and straw yields of 8.25 and 8.39 t ha−1, respectively. These values are low for a favorable area and correspond to a semi-arid area. In addition, no effects of nitrogen dose were observed due to water stress, which reduced nitrogen use efficiency. Nachit is the most adapted variety under NT, with the highest yield (5.1 t ha−1) under a low dose of nitrogen (20 kg N ha−1), followed by Faraj (4.7 t ha−1), still under NT but with a higher nitrogen dose (40 kg N ha−1) and Nachit (4.5 t ha−1) with the minimum nitrogen dose but under both NT and CT. In conclusion, Nachit and Faraj wheat varieties performed the best under no-tillage conditions with the minimal nitrogen dose. However, grain yield values were reduced, owing to water stress, which reduced nitrogen use efficiency.
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Pisani Gareau, Tara, Christina Voortman, and Mary Barbercheck. "Carabid beetles (Coleoptera: Carabidae) differentially respond to soil management practices in feed and forage systems in transition to organic management." Renewable Agriculture and Food Systems 35, no. 6 (August 13, 2019): 608–25. http://dx.doi.org/10.1017/s1742170519000255.
Full textAbstract:
AbstractWe conducted a 3-yr cropping systems experiment in central Pennsylvania, USA, to determine the effects of initial cover crop species, tillage and resulting environmental variables on the activity–density (A–D), species richness, community composition and guild composition of carabid beetles (Carabidae: Coleoptera) during the transition from conventional to organic production. We compared four systems in a factorial combination of a mixed perennial sod (timothy, Phleum pratense L.) and legumes (red clover, Trifolium pratense L.) or annual cereal grain (cereal rye, Secale cereale L.) followed by a legume (hairy vetch, Vicia villosa Roth) as initial cover crops, and soil management using full tillage (moldboard plow) or reduced tillage (chisel plow) implemented in soybeans followed by maize in the subsequent year. The experiment was established twice, first in autumn 2003 (S1) and again in autumn 2004 (S2) in an adjacent field, in a randomized complete-block design with four replicates in each Start. We collected a total of 2181 adult carabid beetles. Approximately 65% of the carabid beetles collected were from six species. Indicator Species Analysis showed that several carabid species were indicative of treatment, e.g., Poecilus chalcites was a strong indicator for treatments with an initial cereal rye cover crop. Eleven environmental variables explained variation in carabid A–D, richness and the A–D of species categorized by size class and dominant trophic behavior, respectively, but varied in significance and direction among guilds. Soil moisture was a significant effect for total carabid A–D in both S1 and S2. Redundancy analyses revealed some similar and some idiosyncratic responses among informative species for the cover crop×tillage treatments through the 3-yr rotation. The most consistent factors that distinguished species assemblages among years and treatments were the number and intensity of soil disturbances and perennial weed density. The consistent occurrence of soil disturbance indicators in multivariate analyses suggests that future studies that aim to compare the effects of nominal soil management treatments on carabid beetles and other soil-associated arthropods should quantify frequency and intensity of disturbance associated with crop management practices.
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Campbell, C. A., B. G. McConkey, R. P. Zentner, F. B. Dyck, F. Selles, and D. Curtin. "Carbon sequestration in a Brown Chernozem as affected by tillage and rotation." Canadian Journal of Soil Science 75, no. 4 (November 1, 1995): 449–58. http://dx.doi.org/10.4141/cjss95-065.
Full textAbstract:
Soil organic matter is important because it influences the productivity and physical well-being of soils. Recently, increased attention has focussed on soil organic matter as a possible sink for C02-C. Despite this interest, there is a lack of data for quantifying the effect of tillage on soil organic matter. Between 1981 and 1994, two tillage experiments were conducted at Swift Current, Saskatchewan, on Swinton loam, an Orthic Brown Chernozemic soil. Organic C and N were monitored periodically to quantify the effects of crop rotation [continuous spring wheat (Cont W) (Triticum aestivum L.) vs. fallow–wheat (F-W)] and tillage management [no-tillage (NT) vs. conventional tillage (CT) involving primarily use of a cultivator and rodweeder]. The effect of snow management on soil organic matter was also evaluated in one experiment, but this factor was not significant. Organic matter changes were mainly observed in the 0- to 7.5-cm soil depth. Carbon and N were greater in both concentrations and amounts in Cont W than in F–W; the latter cropping system was employed on this land during the previous 70–80 yr. In the 0- to 7.5-cm depth, the amount of organic matter was only moderately greater in NT than CT in the Cont W systems while in the F-W systems tillage was not significant (P > 0.10). During the 12-yr period, Cont W (average of NT and CT) gained about 2 t ha−1 more C in the top 15 cm of soil than F-W (average of NT and CT), with most of the increase occurring in the first 5 yr. Further, Cont W (NT) gained about 1.5 t ha−1 more C than Cont W (CT), and F-W (NT) gained about 0.5 t ha−1 more than F-W (CT). When a system that was maintained as Cont W (NT) for 9 yr was changed to Cont W (CT) for 3 yr and then summerfallowed (CT) for 1 yr, soil organic matter declined (P < 0.05). Our observations, supported by calculations based on crop residue production, indicated that an increase in organic C, averaging about 0.4–0.5 t ha−1 yr−1, has occurred in the top 15 cm of soil in Cont W (NT) between 1982 and 1993. However, because of uncertainty in our estimated C levels at the start of the experiment, the nature of the rate of C increase (linear or curvilinear) is not known. Key words: Organic C, organic N, no-till, summerfallow
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Dalal, RC, WM Strong, EJ Weston, JE Cooper, KJ Lehane, AJ King, and CJ Chicken. "Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage, or legumes. 1. Organic matter status." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 903. http://dx.doi.org/10.1071/ea9950903.
Full textAbstract:
Management practices involving legume leys, grain legumes, and no-tillage and stubble retention, along with nitrogen (N) fertiliser application for wheat cropping, were examined for their effectiveness in increasing soil organic matter (0-10 cm depth) from 1986 to 1993 in a field experiment on a Vertisol at Warra, Queensland. The treatments were (i) grass + legume leys (purple pigeon grass, Setaria incrassata; Rhodes grass, Chloris gayana; lucerne, Medicago sativa; annual medics, M. scutellata and M. truncatula) of 4 years duration followed by continuous wheat; (ii) 2-year rotation of annual medics and wheat (Triticum aestivum cv. Hartog); (iii) 2-year rotation of lucerne and wheat; (iv) 2-year rotation of chickpea (Cicer arietinum cv. Barwon) and wheat; (v) no-tillage (NT) wheat; and (vi) conventional tillage (CT) wheat. Fertiliser N as urea was applied to both NT wheat and CT wheat at 0,25, and 75 kg N/ha. year. The CT wheat also received N at 12.5 and 25kg N/ha. year. After 4 years, soil organic carbon (C) concentration under grass + legume leys increased by 20% (650 kg C/ha. year) relative to that under continuous CT wheat. Soil total N increased by 11, 18, and 22% after 2, 3, and 4 years, respectively, under grass + legume leys relative to continuous CT wheat. These increases in soil organic matter were mostly confined to the 0-2.5 cm layer. After the start of wheat cropping, organic C and total N levels declined steadily but were still higher than under CT wheat and higher than initial values in December 1985. Although 2-year rotations of lucerne-wheat and medic-wheat had a small effect on soil organic C, soil total N concentrations were higher than in the chickpea-wheat rotation and continuous CT wheat from November 1990 to November 1992. Soil under chickpea-wheat rotation had organic C and total N concentrations similar to continuous CT wheat, although from the former, about 70 kg/ha. year of extra N was removed in the grain from 1989 to 1993. No-tillage practice had a small effect on soil organic C, although total N concentration was higher than under CT wheat in November 1993. These effects were mainly confined to the surface 0-2.5 cm depth. The C to N ratio was only affected in soil under grass + legume leys, and no-tillage treatments. These data show that restoration of soil organic matter in Vertisol requires grass + legume leys, primarily due to increased root biomass, although soil total N can be enhanced by including legume leys for longer duration in cropping systems in the semi-arid and subtropical environment.
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Faqih, Achmad, Dukat Dukat, and Trihayana Trihayana. "PENGARUH DOSIS DAN WAKTU APLIKASI PUPUK UREA TERHADAP PERTUMBUHAN DAN HASIL TANAMAN JAGUNG MANIS (Zea mays Var. saccharata Sturt) KULTIVAR BONANZA F1." Agroswagati Jurnal Agronomi 7, no. 1 (April 20, 2019): 18. http://dx.doi.org/10.33603/agroswagati.v7i1.2846.
Full textAbstract:
The aim of this study: (1) To determine the effect the combination of the dose and time application of urea fertilizer on the growth and yield of sweet corn (Zea mays Var.Saccharata Sturt) Cultivars Bonanza F1. (2) To determine the effect the combination of the best dose and time application of urea fertilizer on the growth and yield of sweet corn (Zea mays Var.Saccharata Sturt) Cultivars Bonanza F1. The research was conducted in the village of Susukan Tangkil District of Cirebon - West Java, from September until November, 2018.The research method used was the experimental method with a randomized block design (RAK). This experiment consisted of nine combinations dosage of potassium fertilizer and tillage systems each repeated three times, so there are 27 experimental plots. The combination treatment was tested in the field are: A (urea fertilizer 50 kg/ha and one time application), B (urea fertilizer 50 kg/ha and two time application), C (urea fertilizer 50 kg/ha and three time application), D (urea fertilizer 100 kg/ha and one time application), E (urea fertilizer 100 kg/ha and two time application), F (urea fertilizer 100 kg/ha and three time application), G (urea fertilizer 150 kg/ha and one time application), H (urea fertilizer 150 kg/ha and two time application), I (urea fertilizer 150 kg/ha and three time application).The results showed that: (1) There is a real effect treatment the combination of the dose and time application of urea fertilizer on plant height age of 47 and 54 Days After Planting (DAP), the number of leaves per plant of 47 and 54 Days After Planting (DAP), diameter of age stem of 47 and 54 Days After Planting (DAP), the length and diameter of the cob with husk, and corncob with husk per plot. (2) The combination of dose and time application of the best urea fertilizer from cob weighted per plot in treatment I (urea fertilizer 150 kg/ha and three time application) with weight 9,07 kg equal to 19,33 ton/ha.
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Faqih, Achmad, Dukat Dukat, and Trihayana Trihayana. "PENGARUH DOSIS DAN WAKTU APLIKASI PUPUK UREA TERHADAP PERTUMBUHAN DAN HASIL TANAMAN JAGUNG MANIS (Zea mays Var. saccharata Sturt) KULTIVAR BONANZA F1." Agroswagati Jurnal Agronomi 7, no. 1 (April 20, 2019): 18. http://dx.doi.org/10.33603/agroswagati.v7i1.2846.
Full textAbstract:
The aim of this study: (1) To determine the effect the combination of the dose and time application of urea fertilizer on the growth and yield of sweet corn (Zea mays Var.Saccharata Sturt) Cultivars Bonanza F1. (2) To determine the effect the combination of the best dose and time application of urea fertilizer on the growth and yield of sweet corn (Zea mays Var.Saccharata Sturt) Cultivars Bonanza F1. The research was conducted in the village of Susukan Tangkil District of Cirebon - West Java, from September until November, 2018.The research method used was the experimental method with a randomized block design (RAK). This experiment consisted of nine combinations dosage of potassium fertilizer and tillage systems each repeated three times, so there are 27 experimental plots. The combination treatment was tested in the field are: A (urea fertilizer 50 kg/ha and one time application), B (urea fertilizer 50 kg/ha and two time application), C (urea fertilizer 50 kg/ha and three time application), D (urea fertilizer 100 kg/ha and one time application), E (urea fertilizer 100 kg/ha and two time application), F (urea fertilizer 100 kg/ha and three time application), G (urea fertilizer 150 kg/ha and one time application), H (urea fertilizer 150 kg/ha and two time application), I (urea fertilizer 150 kg/ha and three time application).The results showed that: (1) There is a real effect treatment the combination of the dose and time application of urea fertilizer on plant height age of 47 and 54 Days After Planting (DAP), the number of leaves per plant of 47 and 54 Days After Planting (DAP), diameter of age stem of 47 and 54 Days After Planting (DAP), the length and diameter of the cob with husk, and corncob with husk per plot. (2) The combination of dose and time application of the best urea fertilizer from cob weighted per plot in treatment I (urea fertilizer 150 kg/ha and three time application) with weight 9,07 kg equal to 19,33 ton/ha.
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Olson, Kenneth R., Stephen A. Ebelhar, and James M. Lang. "Effects of 24 Years of Conservation Tillage Systems on Soil Organic Carbon and Soil Productivity." Applied and Environmental Soil Science 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/617504.
Full textAbstract:
The 24-year study was conducted in southern Illinois (USA) on land similar to that being removed from Conservation Reserve Program (CRP) to evaluate the effects of conservation tillage systems on: (1) amount and rates of soil organic carbon (SOC) storage and retention, (2) the long-term corn and soybean yields, and (3) maintenance and restoration of soil productivity of previously eroded soils. The no-till (NT) plots did store and retain 7.8 Mg C ha−1more and chisel plow (CP) −1.6 Mg C ha−1less SOC in the soil than moldboard plow (MP) during the 24 years. However, no SOC sequestration occurred in the sloping and eroding NT, CP, and MP plots since the SOC level of the plot area was greater at the start of the experiment than at the end. The NT plots actually lost a total of −1.2 Mg C ha−1, the CP lost −9.9 Mg C ha−1, and the MP lost −8.2 Mg C ha−1during the 24-year study. The long-term productivity of NT compared favorably with that of MP and CP systems.
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Fedorov, S. E., M. N. Chatkin, A. A. Zhalnin, and N. A. Zhalnin. "Experimental study of the elastic S-shaped cultivator rack." Traktory i sel hozmashiny 84, no. 5 (May 15, 2017): 53–57. http://dx.doi.org/10.17816/0321-4443-66303.
Full textAbstract:
Cultivating paws on elastic struts at work have a deviation from the established depth of processing by 10-15 % more than with a rigid suspension and do not preserve the optimal cutting geometry. With increasing speed and depth of treatment, tractive resistance and deflection of the paw from a given depth of processing increase. Therefore, to ensure the quality and efficiency of the combined cultivator equipped with elastic S-shaped struts, it is necessary to change the rigidity of the racks. The purpose of the study is to improve the quality and reduce the energy consumption of surface tillage by regulating and optimizing the rigidity of the elastic strut of the cultivator. To study the work of the elastic S-pillar, the method of full factorial experiment was used, which allowed obtaining mathematical models, taking into account the selected controlled factors. For the controlled variables, the factors characterizing the work properties of the elastic S-pillar and having certain numerical values were taken. In the course of the study, the influence of the depth of treatment, the speed of the aggregate and the stiffness of the strut on the traction resistance and the deviation of the paw was studied. The results of the research showed that with an increase in processing depth from 0,04 m to 0,12 m at a speed of 3 m/s, the traction resistance of the S-pillar will increase from 105 N to 670 N. It should be noted that increasing the stiffness of the rack from 6226 N/m to 21815 N/m leads to a reduction in traction resistance by 100 N. With increasing depth of processing and speed of the unit - the deviation of the toe of the paw increases. With increasing stiffness of the stand, the deviation of the toe of the paw decreases. The maximum deviation is observed at a speed of 3 m/s, a depth of 0,12 m, rigidity of the rack 6826 N/m. As a result of the study, in order to fulfill the agrotechnical requirements for surface tillage, it is proposed to install a stiffness regulator in the design of the elastic S-bar.
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Mehanni, AH. "Reclamation of a saline/sodic soil by aquifer pumping, application of tillage and gypsum and reuse of saline groundwater." Australian Journal of Experimental Agriculture 27, no. 3 (1987): 381. http://dx.doi.org/10.1071/ea9870381.
Full textAbstract:
In the Goulburn Valley, at a site near Tongala, Vic., shallow perched watertables receded from 18 to 135 cm below the surface and the piezometric pressure was reduced from 16 to 180 cm below the surface in a saline/sodic soil 3 months from the start of pumping. Consequently soil salinity was reduced from ECe 12.3 to 7.3 dS/m in the top 30 cm under 1 15 mm ofrainfall. Further reduction in salinity to ECe 3 dS/m was achieved after 19 months. The presence of electrolytes in irrigation water preserved soil permeability during the irrigation season, while gypsum was beneficial during the winter rainfall season. Perennial pasture was established 11 months after pumping commenced. Weeds that originally dominated the site disappeared, while clover produced 70% of total dry matter.
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Barclay, Gordon J., Martha V. Andrews, Anne M. Blackham, D. Gilbertson, Jenny A. Lee, Marijke Van der Veen, J. S. Rideout, and Angela Townshend. "Excavations at Upper Suisgill, Sutherland." Proceedings of the Society of Antiquaries of Scotland 115 (November 30, 1987): 159–98. http://dx.doi.org/10.9750/psas.115.159.198.
Full textAbstract:
A narrow section across an area between two souterrains was excavated in advance of road realignment; part of one of the souterrains was also exposed. The excavation revealed deposits up to c 1.8 m deep in places, largely made up of material washed downhill on to the site.
Early-mid first millennium BC: Period I – ard tillage; II – construction and reconstruction of a round timber house, and the erection of a stone-faced earth bank; III – tillage; IV – the construction, and destruction by fire, of a post-built structure; beginning of water scouring of the site and start of hillwash deposition.
Settlement was re-established later in the millennium on the surface of the hillwash deposits (Period VI). This was subsequently covered by more hillwash. Recent settlement was represented by uncharacterized activity at the south edge of the excavated area and by two post-medieval buildings (associated with a settlement to the SE) the later of which was probably demolished during 19th-century road building.
Quantities of pottery of 10 fabrics and three main styles (I, flat rims; 2, splayed rims; 3, everted rims) were found. Carbonized plant material was recovered, including many grains of six-row (mainly naked) barley, a little wheat, and oats, possibly domesticated. The pollen analysis of a peat column taken from a bog 2 km from the site showed a notable forest decline at c 4500 BP, followed by a pinebirch regeneration, followed, shortly before 1700 BP, by a further decline.
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Goplen, Jared J., Craig C. Sheaffer, Roger L. Becker, Roger D. Moon, Jeffrey A. Coulter, Fritz R. Breitenbach, Lisa M. Behnken, and Jeffrey L. Gunsolus. "Giant Ragweed (Ambrosia trifida) Emergence Model Performance Evaluated in Diverse Cropping Systems." Weed Science 66, no. 1 (August 17, 2017): 36–46. http://dx.doi.org/10.1017/wsc.2017.38.
Full textAbstract:
Accurate weed emergence models are valuable tools for scheduling planting, cultivation, and herbicide applications. Multiple models predicting giant ragweed emergence have been developed, but none have been validated in diverse crop rotation and tillage systems, which have the potential to influence weed emergence patterns. This study evaluated the performance of published giant ragweed emergence models across various crop rotations and spring tillage dates in southern Minnesota. Across experiments, the most robust model was a mixed-effects Weibull (flexible sigmoidal function) model predicting emergence in relation to hydrothermal time accumulation with a base temperature of 4.4 C, a base soil matric potential of −2.5 MPa, and two random effects determined by overwinter growing degree days (GDD) (10 C) and precipitation accumulated during seedling recruitment. The deviations in emergence between individual plots and the fixed-effects model were distinguished by the positive association between the lower horizontal asymptote (Drop) and maximum daily soil temperature during seedling recruitment. This finding indicates that crops and management practices that increase soil temperature will have a shorter lag phase at the start of giant ragweed emergence compared with practices promoting cool soil temperatures. Thus, crops with early-season crop canopies such as perennial crops and crops planted in early spring and in narrow rows will likely have a slower progression of giant ragweed emergence. This research provides a valuable assessment of published giant ragweed emergence models and illustrates that accurate emergence models can be used to time field operations and improve giant ragweed control across diverse cropping systems.
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Chidumayo, Emmanuel N. "Effect of tillage, clipping and climate on grass phytomass in a Zambian savanna." Journal of Tropical Ecology 19, no. 4 (July 2003): 407–15. http://dx.doi.org/10.1017/s0266467403003456.
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The effect of tillage, clipping, precipitation and temperature on above-ground grass production was investigated in permanent plots at a Zambian savanna site for 5 y (1996^2001) by the harvest method. Mean species richness was 4.6 species m-2 with a total of 15 species at the study site. Mean end-of-season grass phytomass was 464 g m-2 with no statistically significant differences among years in control quadrats. Grass phytomass recovered within two wet seasons after tillage and a similar trend was observed after cessation of a 2-y monthly harvesting regime. However, in experimental quadrats, plot, treatment and year had significant effects on grass production. Previous- and current-season precipitation had no significant effect on end-of-wet-season grass phytomass but phytomass of the previous season explained 27-53% of the variation in end-of-wet-season phytomass. Grass production peaked in the wet season and declined sharply as the dry season progressed. The interaction between precipitation, temperature, harvesting and duration of the dry season explained 81-91% of the variation in daily grass production but the significance of the interactions varied with season and duration of harvesting. Precipitation-use efficiency (PUE) of grasses declined from 2.25 g m-2 mm-1 at the start of the wet season in December to 0.25 g m-2 mm-1 at the end of the season in March. Monthly harvesting for 1 y reduced PUE to less than 25%. The results indicate very complex relationships between above-ground grass production (dependent variable) and climate and land-use (independent) factors that makes the prediction of grass production in central southern African savannas difficult.
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Morra, Luigi, Maurizio Bilotto, Salvatore Baiano, Giovanni Saviello, and Domenico Cerrato. "Annual effects of different organic fertilisers in a baby leaf crops system under tunnel in Southern Italy." Italian Journal of Agronomy 10, no. 3 (September 28, 2015): 144. http://dx.doi.org/10.4081/ija.2015.642.
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In a farm devoted to the production of fresh-cut leafy vegetables located in Eboli (Salerno), it was carried out a trial to compare the effects on crops and soil organic carbon (SOC) of biowaste compost, olive pomace compost, buffalo manure applied to soil in two doses (15 and 30 t ha<sup>−1</sup> fresh weight). The amendments were tested in order to start in defining a feasible strategy for the recovery/maintenance of soils in degradation due to the organic matter depletion triggered by the intensive soil tillage and the lack of organic matter returned to soil. In the year following the soil amendment, it was studied the crop sequence: rocket-basil-rocket. Analysis of nitrates concentration in leaves of rocket was carried out on samples of all the treatments picked up in the two cycles of rocket. Along the year, we observed that the higher yields promoted in the first six months (May-September) from the dose 15 t ha<sup>−1</sup>, were obtained with the dose 30 t ha<sup>−1</sup> in the successive six months (November-May). This was due, probably, to the larger stock of total N supplied with dose 30 and its release in time. Buffalo manure amendment showed a higher quickness than composts in the supplying mineral nitrogen to the first crops. On the other hand, nitrates in leaves of rocket exceeded, more frequently, the limits fixed in EU Regulation n. 1258/2011 in the plots amended with buffalo manure. Instead, the treatments with olive pomace compost showed to exceed rarely the EU limits. Under tunnel, the intensive management based on 4-5 crop cycles per year and as much soil tillage, appeared the first cause to explain the lack of significant variation in SOC of plots treated with organic improvers after one year from their distribution. This result let us to suppose the need to study some modifications of the standard farm management in order to reduce the number of soil tillage in a year and, as a consequence, the main stress causing the high carbon mineralisation rate in soil under tunnel.
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Smith, Richard G., Randa Jabbour, Andrew G. Hulting, Mary E. Barbercheck, and David A. Mortensen. "Effects of Initial Seed-Bank Density on Weed Seedling Emergence during the Transition to an Organic Feed-Grain Crop Rotation." Weed Science 57, no. 5 (October 2009): 533–40. http://dx.doi.org/10.1614/ws-09-031.1.
Full textAbstract:
The transition period to certified organic production can present a significant weed management challenge for growers. Organic certification requires that prohibited fertilizers and pesticides must not have been used for 36 mo before harvest of the first organic crop. Understanding how organic management practices and initial weed seed-bank densities affect weed population dynamics during the transition period may improve weed management efficacy and adoption of organic practices. We examined how tillage systems (full or reduced) and cover crop species planted during the first transition year (rye or a mixture of timothy and red clover) affect the seedling densities of three common annual weed species, common lambsquarters, velvetleaf, and foxtail spp., during the 3-yr transition period. Weed seeds were applied in a one-time pulse at the beginning of the study at three densities, low, medium, and high (60, 460, and 2,100 seeds m−2, respectively), and cumulative seedling densities of each species were assessed annually. Treatment factors had variable and species-specific effects on weed seedling densities. In general, the full-tillage system, with an initial cover crop of timothy and red clover, resulted in the lowest density of weed seedlings following seed-bank augmentation. There was little consistent association between the initial densities of applied weed seeds in the weed seed bank at the start of the transition and weed seedling densities at the end of the transition period. This suggests that when multiple crop and weed cultural management practices are employed during the organic transition period, initial failures in weed management may not necessarily lead to persistent and intractable annual weed species management problems following organic certification.
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Riar, Dilpreet S., Jason K. Norsworthy, Lawrence E. Steckel, Daniel O. Stephenson, Thomas W. Eubank, Jason Bond, and Robert C. Scott. "Adoption of Best Management Practices for Herbicide-Resistant Weeds in Midsouthern United States Cotton, Rice, and Soybean." Weed Technology 27, no. 4 (December 2013): 788–97. http://dx.doi.org/10.1614/wt-d-13-00087.1.
Full textAbstract:
In fall 2011, cotton and soybean consultants from Arkansas, Louisiana, Mississippi, and Tennessee were surveyed through direct mail and on-farm visits, and rice consultants from Arkansas and Mississippi were surveyed through direct mail to assess the importance and level of implementation of herbicide resistance best management practices (HR-BMPs) for herbicide-resistant weeds. Proper herbicide timing, clean start with no weeds at planting, application of multiple effective herbicide modes of action, use of full labeled herbicide rates, and prevention of crop weed seed production with importance rating of ≥ 4.6 out of 5.0 were perceived as the most important HR-BMPs in all crops. Purchase of certified rice seed was on 90% of scouted hectares. In contrast, least important HR-BMPs as perceived by consultants with importance ratings of ≤ 4.0 in cotton, ≤ 3.7 in rice, and ≤ 3.8 in soybean were cultural practices such as manual removal of weeds; tillage including disking, cultivation, or deep tillage; narrow (≤ 50 cm)-row crops, cover crops, and altered planting dates. Narrow crop rows and cover crops in cotton; altered planting dates in cotton and soybean; and cleaning of farm equipment and manual weeding in rice and soybean is currently employed on ≤ 20% of scouted hectares. Extra costs, time constraints, adverse weather conditions, lack of labor and equipment, profitability, herbicide-related concerns, and complacency were perceived as key obstacles for adoption of most HR-BMPs. With limited adoption of most cultural practices that reduce risks of herbicide-resistant weeds, there are opportunities to educate growers concerning the proactive need and long-term benefits of adopting HR-BMPs to ensure sustainable weed management and profitable crop production.
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Demydenko, O., P. Boyko, and V. Velychko. "Long-term dynamics of humus content under different technologies of soil tillage." Agricultural Science and Practice 5, no. 1 (April 15, 2018): 3–16. http://dx.doi.org/10.15407/agrisp5.01.003.
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The continuous agronomic experiment revealed long-term dynamics of the total humus content and presented a forecast of the change in humus content in typical low humus chernozem under different technologies of till- age till 2050. Aim. To determine the rates of humus accumulation dynamics and mineralization of total humus and to develop the forecast of the change in its content within a continuous agronomic experiment under long- standing application of different technologies of soil tillage to typical low humus chernozem of the Left-Bank Forest-Steppe of Ukraine. Methods. Field, laboratory-analytical, mathematical and statistical. Results. The application of different technologies of tillage to typical low humus chernozem for 42 years resulted only in the delay in dehumifi cation processes and some stabilization of humus mineralization, but it did not promote its preservation and extended restoration to the initial level as of the start of the experiment. The increase in the total humus content for simple and extended restoration of humus in the centennial cycle equaled 20–25 t and 30–33 t per 1 ha respectively. To ensure the increase in content and reserves of humus for 42 years, it is necessary to introduce 10–12 t of humus per 1 ha for simple restoration of total humus content and 14–15 t per 1 ha – for extended restoration annually. Conclusions. Simple restoration of humus in typical chernozem may be stated after achieving its actual (2017) content of at least 90 % from the content as of the beginning of the centennial cycle (92 years), which ensures maximal approximation to the non-decreasing cycle of humus dynamics trends in the centennial cycle. If the humus content is ensured in the actual measurement for the level, exceeding 90 % from the initial content, and dynamics trends are growing, one may state the success of achieving the state of extended restoration of humus. The obtained state of simple and extended accumulation of humus is ensured by the positivity of the trends of humus increase during the continuous experiment (42 years) with simultaneous decrease in dehumifi cation process in the centennial cycle (92 years) which is impos- sible to neutralize completely.
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Heenan, DP, WJ McGhie, FM Thomson, and KY Chan. "Decline in soil organic carbon and total nitrogen in relation to tillage, stubble management, and rotation." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 877. http://dx.doi.org/10.1071/ea9950877.
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The influence of rotation, tillage, stubble management, and nitrogen (N) fertiliser on soil organic carbon (C) and total nitrogen (N) was studied between 1979 and 1993 in a field experiment at Wagga Wagga, New South Wales, on a red earth. The rotations included lupin-wheat (LW), subterranean clover-wheat (SW), and continuous wheat (WW) with and without N fertiliser (100 kg N/ha). At the start of the experiment the soil organic C and N in the surface 10 cm were high following many years of subterranean clover based pasture. The trends in soil organic C varied considerably between treatments from near equilibrium levels for SW direct-drilled and stubble-retained to annual losses of 400 kg/ha for WW conventionally cultivated and stubble burnt. Similarly, total soil N content over time varied from equilibrium levels to highly significant declines of 53 kg/ha. year for WW conventionally cultivated and stubble burnt. Both direct drilling and stubble retention reduced the losses of organic C and N compared with conventional cultivation and burning, with greatest loss occurring when cultivation and stubble burning were combined. SW and LW produced a similar contribution of fixed N to total N product removal, but greater benefits to following wheat crops were provided by SW rotations. Where losses of organic C and N were recorded there was no evidence of equilibrium levels being reached after 14 years.
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EITZINGER, J., S. THALER, E. SCHMID, F. STRAUSS, R. FERRISE, M. MORIONDO, M. BINDI, et al. "Sensitivities of crop models to extreme weather conditions during flowering period demonstrated for maize and winter wheat in Austria." Journal of Agricultural Science 151, no. 6 (October 9, 2012): 813–35. http://dx.doi.org/10.1017/s0021859612000779.
Full textAbstract:
SUMMARYThe objective of the present study was to compare the performance of seven different, widely applied crop models in predicting heat and drought stress effects. The study was part of a recent suite of model inter-comparisons initiated at European level and constitutes a component that has been lacking in the analysis of sources of uncertainties in crop models used to study the impacts of climate change. There was a specific focus on the sensitivity of models for winter wheat and maize to extreme weather conditions (heat and drought) during the short but critical period of 2 weeks after the start of flowering. Two locations in Austria, representing different agro-climatic zones and soil conditions, were included in the simulations over 2 years, 2003 and 2004, exhibiting contrasting weather conditions. In addition, soil management was modified at both sites by following either ploughing or minimum tillage. Since no comprehensive field experimental data sets were available, a relative comparison of simulated grain yields and soil moisture contents under defined weather scenarios with modified temperatures and precipitation was performed for a 2-week period after flowering. The results may help to reduce the uncertainty of simulated crop yields to extreme weather conditions through better understanding of the models’ behaviour. Although the crop models considered (DSSAT, EPIC, WOFOST, AQUACROP, FASSET, HERMES and CROPSYST) mostly showed similar trends in simulated grain yields for the different weather scenarios, it was obvious that heat and drought stress caused by changes in temperature and/or precipitation for a short period of 2 weeks resulted in different grain yields simulated by different models. The present study also revealed that the models responded differently to changes in soil tillage practices, which affected soil water storage capacity.
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Heenan, DP, AC Taylor, BR Cullis, and WJ Lill. "Long term effects of rotation, tillage and stubble management on wheat production in southern NSW." Australian Journal of Agricultural Research 45, no. 1 (1994): 93. http://dx.doi.org/10.1071/ar9940093.
Full textAbstract:
A long term field experiment began in 1979 at Wagga Wagga, N.S.W., to compare the sustainability of a range of rotation, tillage and stubble management systems on a red earth. This paper reports yield, yield components and grain protein of wheat for 1979-90. Rotations considered were alternating lupin-wheat (LW), lupin-wheat-wheat (LWW), continuous wheat (WW) with and without N fertilizer (100 kg N/ha), and alternating sub-clover-wheat (CW). Soil N supply at the start of the experiment was high following many years of sub-clover based pasture. From 1979 to 1983, there was a negative grain yield response to N fertilizer and no response to a legume in rotation except in the drought of 1982 when low yields were recorded from LW. Thereafter, a positive grain yield response was usually produced to N fertilizer in WW rotations, until 1989 and 1990, when these crops displayed aluminium toxicity sym ptoms. Overall, average grain yields from legume rotations were higher than WW with added N fertilizer. Since 1983, LW rotations consistently produced higher mean grain yields than CW, but mean grain protein and total N uptake were lower. Yields and N uptake by the second wheat crop in a LWW rotation indicated little carryover of benefits from the lupins. Slightly higher mean grain yield and harvest index, but lower mean grain protein, were produced by direct drilling, compared with cultivation before sowing, following lupins or sub-clover. However, retaining stubble rather than burning in autumn consistently reduced grain yields. There was no evidence that early burial of wheat stubble following summer rain, rather than incorporation in autumn, improved grain yield or total N uptake. The build-up of giant brome grass and diseases, particularly where stubble was retained and crops direct-drilled, casts some doubt on the long term sustainability of these short term rotations in this environment.
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Cardina, John, Catherine P. Herms, Daniel A. Herms, and Frank Forcella. "Evaluating Phenological Indicators for Predicting Giant Foxtail (Setaria faberi) Emergence." Weed Science 55, no. 5 (October 2007): 455–64. http://dx.doi.org/10.1614/ws-07-005.1.
Full textAbstract:
We evaluated the use of ornamental plants as phenological indicators for predicting giant foxtail emergence and compared their performance with predictions based upon Julian day, cumulative growing degree–days (GDD), and the WeedCast program. From 1997 to 2001, we monitored giant foxtail emergence in a field experiment with and without fall and spring tillage to estimate the dates of 25, 50, and 80% emergence; we also recorded dates of first and full bloom of 23 ornamental plant species. Dates of weed emergence and ornamental blooming for 1997 to 2000 were compiled in a phenological calendar consisting of 54 phenological events for each year, and events were ordered by average (1997 to 2000) cumulative GDD (January 1 start date, 10 C base temperature). Bloom events occurring just before the giant foxtail emergence events were chosen as the phenological indicators for 2001. The Julian day method used the average (1997 to 2000) dates of foxtail emergence to predict 2001 emergence. The GDD model (October 1 start date, 0 C base temperature) was chosen by determining the combination of start date and base temperature that provided the lowest coefficient of variation for the 1997 to 2000 data. The WeedCast prediction was generated using local soil and environmental data from 2001. The rank order of the 54 phenological events in 2001 showed little deviation from the 4-yr (1997 to 2000) average rank order (R2= 0.96). The phenological calendar indicated that, on average, 25% of giant foxtail seedlings had emerged when red chokeberry was in first bloom, and 80% of seedlings had emerged around the time multiflora rose was in full bloom. We compared the phenological calendar predictions for 25, 50, and 80% emergence with those based on Julian day, cumulative GDD, and WeedCast. The average deviation in predictions ranged from 4.4 d for the phenological calendar to 11.4 d for GDD. In addition to being generally more accurate, the phenological calendar approach also offers the advantage of providing information on the order of phenological events, thus helping to anticipate the progress of emergence and to plan and implement management strategies.
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Way, Thomas R., Thomas R. Way, Ted S. Kornecki, Haile Tewolde, Dexter B. Watts, Ted S. Kornecki, Haile Tewolde, and Dexter B. Watts. "Soil Rut Effects on Planter Performance for Cotton in a Conservation Tillage System." Applied Engineering in Agriculture 38, no. 6 (2022): 951–59. http://dx.doi.org/10.13031/aea.15144.
Full textAbstract:
Highlights Soil rutting commonly occurs during harvest and these ruts can adversely affect row crop planter performance. Four rut types were used, two formed by a tire and two formed by cutting the soil and removing soil from the ruts. Cotton seedling emergence at 15 days after planting typically was greater in unrutted soil than in rutted soil. Regression equations show a trend of decreased emergence as rut depth increased for both a sandy loam and a clay soil. Abstract. Soil rutting commonly occurs during harvest and ruts formed during harvesting can adversely affect row crop planter performance at the start of the subsequent cropping season. We conducted a three-year experiment on a sandy loam and a clay soil to investigate effects of soil ruts on the performance of a row crop planter while planting cotton into a rolled rye cover crop, and effects of planter depth setting on planter performance when planting through soil ruts. The four rut types used, prior to planting the rye cover crop in the fall, were a single tire rut, the rut from a dual pair of tires, and two rut types formed by cutting the soil 25 and 50 mm (1 and 2 in.) deep and removing soil from the ruts. The results show that although not all differences were statistically significant, for five of the six combinations of year and soil, cotton seedling emergence at 15 days after planting was greater when the soil had no rut, i.e., flat unrutted soil, than when the planter traveled across soil ruts while planting. In four of the six combinations of year and soil, emergence was significantly greater for the no rut soil condition than for a rut which was formed the previous fall by cutting 50 mm (2 in.) deep and removing soil from the rut. The three seeding depth settings used in the experiment positioned the bottom peripheries of the two disks of the double-disk opener 28, 35, and 40 mm (1.1, 1.4, and 1.6 in.) beneath the bottom peripheries of the depth-gauge wheels, providing those nominal seeding depths before the closing wheels firmed the soil. The planter depth setting did not significantly affect emergence at 15 days after planting for any of the six combinations of year and soil. Mean values of emergence at 15 days after planting in the sandy loam, averaged over the three years, were 13.9, 11.5, 12.2, 11.4, and 7.6 plants/m of row length (4.2, 3.5, 3.7, 3.5, and 2.3 plants/ft of row length) for the No rut, Single tire, Dual tire, Shallow cut, and Deep cut conditions, respectively. The means in the clay were 13.6, 5.7, 5.8, 12.6, and 7.4 plants/m of row length (4.2, 1.7, 1.8, 3.8, and 2.3 plants/ft of row length), respectively. Regression equations show a trend of decreased emergence as rut depth increased for both soils, with the clay regression line having a greater magnitude slope than the sandy loam line. Keywords: Cotton, Emergence, Planters, Planting, Seeders, Seeding, Soil ruts, Sowing.
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SESTRAS, Radu E. "Introduction pages." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 47, no. 4 (December 24, 2019): I—X. http://dx.doi.org/10.15835/nbha47411760.
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Notulae Botanicae Horti Agrobotanici Cluj-Napoca (NBHA), Issue 4, Volume 47, 2019: The papers published in this issue Vol 47 No 4 (2019) represent new exciting researches in different topics of life science, respectively in plant science, horticulture, agronomy and crop science. Among the interesting articles we invite you to find news about the allelopathic potential of leaf extracts from Dischidia imbricate; quinoa (Chenopodium quinoa) growth in response to fertilization and soil tillage; drought avoidance and phenotypic flexibility of sweet potato (Ipomoea batatas) under water scarcity conditions; development of an efficient ‘one-step freezing’ cryopreservation protocol for a Georgian provenance of chestnut (Castanea sativa) zygotic embryos; effect of nitrogen fertiliser and lime on the floristic composition, soil microbes and dry matter yield of Danthonietum calycinae grassland; screening for salt and water stress tolerance in fir (Abies alba) populations; somatic embryogenesis induction in leaf and root explants of Allophylus edulis; spatial distribution of glomalin-related soil proteins in coniferous and broadleaf mixed temperate forest etc. Notulae Botanicae Horti Agrobotanici Cluj-Napoca journal has moved to online-only publication at the start of 2017; beginning in 2019, the journal appears quarterly. At the same time, we maintain our standard publication, as printed form, with ‘classic’ style - volume, issue, pagination.