• Authors:
    • Alluvione, F.
    • Del Grosso, S. J.
    • Halvorson, A. D.
  • Source: Better Crops with Plant Food
  • Volume: 93
  • Issue: 1
  • Year: 2009
  • Summary: Research shows that application of N fertilizer increases nitrous oxide (N2O) emissions linearly from irrigated cropping systems in Colorado. Conventional-till continuous corn had a higher level of N2O emissions than no-till continuous corn. Inclusion of soybean or dry bean in the no-till corn rotation increased the level of N2O emissions during the corn year of the rotation. Use of controlled release and stabilized N sources reduced N2O emissions under no-till when compared to urea and UAN fertilizer sources. Results of this work indicate that there are crop and fertilizer N management alternatives to reduce N2O emissions from irrigated systems.
  • Authors:
    • Del Grosso, S. J.
    • Halvorson, A. D.
    • Alluvione, F.
  • Source: Journal of Environmental Quality
  • Volume: 38
  • Issue: 5
  • Year: 2009
  • Summary: Long-term effects of tillage intensity, N fertilization, and crop rotation on carbon dioxide (CO2) and methane (CH4) flux. from semiarid irrigated soils are poorly understood. We evaluated effects of. (i) tillage intensity [no-till (NT) and conventional moldboard plow tillage (CT)] in a Continuous corn rotation; (ii) N fertilization levels [0-246 kg N ha(-1) for corn (Zea mays L.); 0 and 56 kg N ha(-1) for dry bean (Phaseolus vulgaris W; 0 and 112 kg N ha(-1) for barley (Hordeum distichon L.)]; and (iii) crop rotation Under NT soil management [corn-barley (NTCB); continuous corn (NT-CC); corn-dry bean (NI-CDb)] on CO2 and CH4 flux from a clay loam soil. Carbon dioxide and CH4 fluxes were monitored one to three times per week using vented nonsready state closed chambers. No-till reduced (14%) growing season (154 d) cumulative CO2 emissions relative to CT (NT 2.08 Mg CO2-C ha(-1); CT 2.41 Mg CO2-C ha(-1)), while N fertilization had no effect. Significantly lower (18%) growing season CO2 fluxes were found in NT-CDb than NT-CC and NT-CB (11.4, 13.2 and 13.9 kg CO2-C ha(-1)d(-1) respectively). Growing season CH4 emissions were higher in NT (20.2 g CH4 ha(-1)) than in CT (1.2 g CH4 ha(-1)). Nitrogen fertilization and cropping rotation did not affect CH4 flux. Implementation of NT for 7 yr with no N fertilization was not adequate for restoring the CH4 oxidation capacity Of this clay learn soil relative to CT plowed and fertilized soil.
  • Authors:
    • Benbrook, C.
  • Source: Critical Issue Report: The First Thirteen Years
  • Year: 2009
  • Summary: Th is report explores the impact of the adoption of genetically engineered (GE) corn, soybean, and cotton on pesticide use in the United States, drawing principally on data from the United States Department of Agriculture. Th e most striking finding is that GE crops have been responsible for an increase of 383 million pounds of herbicide use in the U.S. over the first 13 years of commercial use of GE crops (1996-2008).
  • Authors:
    • Qureshi, Z. A.
    • Neibling, H.
  • Source: Agricultural Water Management
  • Volume: 96
  • Issue: 1
  • Year: 2009
  • Summary: Agricultural production in irrigated areas is becoming more water-constrained. Scheduling the timing of the last irrigation on cereals is one effective method of reducing seasonal water use while maintaining crop yield and quality. The last irrigation application time and its impact on two-row malting barley ( Hordeum distichum cv. Moravian 37) yield, quality, and economic benefits were studied in the 2000, 2001, and 2002 cropping seasons. Irrigation was stopped for the season at Milk, pre-Soft Dough, Soft Dough, and post-Soft Dough grain formation stages. The Soft Dough water cutoff treatment produced the highest grain yield of two-row spring malting barley. Water cutoff before or after Soft Dough stage reduced the grain yield significantly at P
  • Authors:
    • Zibilske, L.
    • Makus, D.
  • Source: Geoderma
  • Volume: 149
  • Issue: 3/4
  • Year: 2009
  • Summary: Management of a black oat ( Avena strigosa [Schreb.]) cover crop by mowing method (none, flail mowing, or sickle bar mowing) affected soil micro environmental conditions and soil microbial and chemical properties. Soil temperatures at depths of 0, 5, 10 and 20 cm were highest in flail mowed treatment plots (up to near 45°C at 5 cm depth), followed by sickle bar mowed plots (averaging 10°C lower at 5 cm depth). Lowest soil temperatures were maintained in plots that were not mowed; averaging 5°C lower at 5 cm depth than the sickle bar mowed plots. Increasing temperature convergence was observed below 5 cm, with the highest temperature (flail mowed treatment) at 32°C and the lowest (not mowed) at 27°C. Microbial biomass increased significantly ( P150 mg C kg -1 in the early fall. beta-glucosidase and alkaline phosphatase activities decreased slowly throughout the experiment, and were significantly greater ( P
  • Authors:
    • Ahmad-ur-Rahman, S.
    • Sadur-Rehman
    • Kamran, K.
  • Source: Sarhad Journal of Agriculture
  • Volume: 25
  • Issue: 4
  • Year: 2009
  • Summary: A field study was conducted to devise a scheme for the integrated management of potato-peach aphid, Myzus persicae (sulzer). Different treatments including, Imidacloprid 25% WP, Tracer 240 EC, Acetamaprid 20 SP, Potato berseem mixed cropping with or without yellow sticky plastic sheet and Potato+Yellow traps were evaluated for their effectiveness. Among all the treatments mixed cropping of potato and berseem together with or without yellow sticky plastic sheet traps was found most effective in reducing the population density of M. persicae i.e. 1.92 aphid per potato leaf and culminated in enhancing the number of associated natural enemies of M. persicae per potato comprising ladybird beetle (9.06), syrphid fly (4.18), green lacewing (8.80), parasitoid mummies (8.18). Also highest yield (12.42 tones ha -1) was recorded from the same treatments. Imidacloprid 25% WP, Acetamaprid 20 SP and Tracer 240 EC were ranked next to potato berseem mixed cropping (with or without yellow traps) in reducing the population density of M. persicae to 2.01, 2.01 and 2.07 aphid per potato leaf, respectively. Imidacloprid 25% WP, Acetamaprid 20 SP and Tracer 240 EC had almost similar effect on the number of natural enemies and on the yield of potato crop.
  • Authors:
    • Al-Dalain, S.
  • Source: Agricultural Journal
  • Volume: 4
  • Issue: 3
  • Year: 2009
  • Summary: This research was carried out during two growing seasons of 2006/2007-2007/2008 in order to determine the effect of intercropping of zea maize ( Miert cultivar) with potato ( Marfona cultivar) on potato growth and on the productivity and Land Equivalent Ratio (LER) of potato and maize. The results of this research showed that intercropping of maize with potato in the case of equal plant densities (4.76 plant m -2) of both crops caused an increase in the mean length of potato stems, which reached 27.45 cm. Moreover, intercropping of maize of 2.38 plant m -2 led into the increase of the mean weight of potato shoots (fresh and dry) to 227 and 21.28 g plant -1 for fresh and dry weight, respectively, besides the increase of the mean weight of potato tubers, which reached 101 g tuber -1. Results also, showed that the number of potato stems and formed tubers were not affected by intercropping of maize with potato. As for productivity, results indicated that the total productivity of each unit area using intercropping system was higher than the productivity of the sole crop, with superiority of treatments with 2.38 plant m -2 of maize and 4.76 plant m -2 of potato where mean yield of 44 ton ha -1, while, the productivity in the other treatments were 36 and 37.8 ton ha -1. LER showed positive influence using the intercropping system compared to the sole cropping, as it shown in the LER values, which were higher (1.43-1.55) in intercropping compared to (1) in the sole cropping.
  • Authors:
    • O'Leary, G.
    • Fisher, P.
    • Abuzar, M.
    • Rab, M.
    • Fitzpatrick, J.
    • Armstrong, R.
  • Source: Crop & Pasture Science
  • Volume: 60
  • Issue: 9
  • Year: 2009
  • Summary: A major barrier to the adoption of precision agriculture in dryland cropping systems is our current inability to reliably predict spatial patterns of grain yield for future crops for a specific paddock. An experiment was undertaken to develop a better understanding of how edaphic and climatic factors interact to influence the spatial variation in the growth, water use, and grain yield of different crops in a single paddock so as to improve predictions of the likely spatial pattern of grain yields in future crops. Changes in a range of crop and soil properties were monitored over 3 consecutive seasons (barley in 2005 and 2007 and lentils in 2006) in the southern section of a 167-ha paddock in the Mallee region of Victoria, which had been classified into 3 different yield (low, moderate, and high) and seasonal variability (stable and variable) zones using normalised difference vegetation index (NDVI) and historic yield maps. The different management zones reflected marked differences in a range of soil properties including both texture in the topsoil and potential chemical-physical constraints in the subsoil (SSCs) to root growth and water use. Dry matter production, grain yield, and quality differed significantly between the yield zones but the relative difference between zones was reduced when supplementary irrigation was applied to barley in 2005, suggesting that some other factor, e.g. nitrogen (N), may have become limiting in that year. There was a strong relationship between crop growth and the use of soil water and nitrate across the management zones, with most water use by the crop occurring in the pre-anthesis/flowering period, but the nature of this relationship appeared to vary with year and/or crop type. In 2006, lentil yield was strongly related to crop establishment, which varied with soil texture and differences in plant-available water. In 2007 the presence of soil water following a good break to the season permitted root growth into the subsoil where there was evidence that SSCs may have adversely affected crop growth. Because of potential residual effects of one crop on another, e.g. through differential N supply and use, we conclude that the utility of the NDVI methodology for developing zone management maps could be improved by using historical records and data for a range of crop types rather than pooling data from a range of seasons.
  • Authors:
    • Aghaalikhani, M.
    • Chaichi, M.
    • Daryaei, F.
  • Source: Iranian Journal of Field Crop Science
  • Volume: 40
  • Issue: 2
  • Year: 2009
  • Summary: To study the mixing rates effects of barley ( Hordeum vulgare L.) and chickpea (desi type) ( Cicer ariethinum L.) on forage production under dryland conditions, a field experiment was conducted at Agricultural Research Station of University of Tehran (Karaj campus) during the 2003-2004 growing season. The 11 Treatments of this experiment were statistically compared based on a Randomized Complete Block Design of three replications. Experimental treatments were arranged as a factorial of sowing density levels of chickpea (100%, 75% and 50% of pure stand) and barley (100%, 75% and 50% of pure stand). Also two additional treatments of chickpea and barley sole cropping were established as control. Barley grain (Valfajr cultivar) and chickpea (4322 ecotype) were simultaneously planted on 20th December, green forage being harvested on 10th May (next year). No manure or irrigation was applied in this experiment (dryland system adopted). Forage was harvested taking into account chickpea phenology (early flowering stage). Barley was the dominant plant in all the mixed treatments. Results showed that forage yield of chickpea and barley was significantly affected by mixing rate (P
  • Authors:
    • Kumpawat, B.
  • Source: Haryana Journal of Agronomy
  • Volume: 25
  • Issue: 1/2
  • Year: 2009
  • Summary: A field experiment was conducted during rainy (kharif) and winter (rabi) seasons of 2004-05 to 2007-08 on clay loam soils at the Dryland Farming Research Station, Arjia, Bhilwara under alkali water irrigation conditions, to find out effect of soil ameliorates viz., control (fallow), green manuring of dhaincha [ Sesbania aculeata (L.) Pers.], application of gypsum @ 50% gypsum requirement (G. R.) and green manuring alongwith gypsum 50% GR and nitrogen levels viz., 50, 75 and 100% RDN on growth, yield and economics of barley ( Hordeum vulgare L.). The study revealed that soil ameliorates improved yield and yield attributes, nutrient uptake, protein content, net return and sustainable yield index (SYI). Green manuring alongwith gypsum 50% GR resulted in the highest grain and straw yield, N and P uptake, crude protein content, net return and sustainable yield index (SYI), wile maximum benefit:cost ratio (3.4) was recorded from green manuring treatment. Increasing dose of nitrogen upto 100% RDN improved significantly yield and yield attributes, crude protein, N and P uptake and recorded highest net return (Rs. 30208/ha), benefit:cost ratio (3.4) and sustainable yield index (0.83).