• Authors:
    • Buzetti, S.
    • Bergamaschine, A. F.
    • Andreotti, M.
    • Pariz, C. M.
    • Costa, N. R.
    • Cavallini, M. C.
  • Source: Archivos de Zootecnia
  • Volume: 60
  • Issue: 232(1)
  • Year: 2011
  • Summary: We evaluated the effect of fertilization with 0, 50, 100 and 200 kg/ha of N, applied in each four growth intervals in the winter/spring season on dry matter yield in 30 days (DMY), leaf chlorophyll index (LCI) and total digestible nutrients (TDN), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin contents, and correlation equations of LCI with DMY and CP content in the marandu and ruziziensis grasses after intercrop arrangements with corn in Red Latosol (Oxisol) under irrigation. The major DMY occurred with photoperiod increasing, however, there were different responses to this attribute over of growth intervals, between and among the grasses with the N fertilization. In irrigated crop-livestock integration under savannah soil is technicality viable the cultivation of marandu and ruziziensis grasses, established by intercrop with corn at sowing or at the N fertilization. As even, in the N fertilization absence, produced satisfactory amounts of forage, with 1733 kg/ha (DMY), at the time of greatest scarcity of roughage to animals (winter/spring season). However, after the corn harvest, the N fertilization increase the DMY and improves the chemical composition, increasing the LCI, and CP and TDN contents, and decreasing NDF and ADF contents in the winter/spring season. The best correlation equations in function of LCI were logatithmica for DMY and potential for CP of the marandu grass and potential for both attributes of the ruziziensis grass.
  • Authors:
    • Rosolem, C. A.
    • dos Santos, G. P.
    • Castoldi, G.
    • Pivetta, L. A.
  • Source: Pesquisa Agropecuária Brasileira
  • Volume: 46
  • Issue: 11
  • Year: 2011
  • Summary: The objective of this work was to assess winter and spring crop effects on soybean root system growth, and on yield, and to compare a direct method (soil core sampling) with an indirect method (with rubidium) in evaluating the root system. The experimental design was a randomized complete block design, in a split-plot arrangement, with four replicates. Plots consisted of the winter crops, triticale (X Triticosecale) and sunflower (Helianthus annuus), and subplots of the spring crops, pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor) and sunn hemp (Crotalaria juncea), besides chisel tillage in 2003 and 2009. Soybean (Glycine max) was grown in the summer, and its root system was evaluated by physical sampling of the roots and by root activity assessment using rubidium. Changes in the architecture or in the activity of soybean roots did not affect yield. The distribution and activity of soybean roots were not significantly affected by the winter cover crops, but root growth was favored after millet and sorghum were grown in the spring. The direct measurement of the soybean root system with an auger has low correlation with root activity.
  • Authors:
    • Strickland, T. C.
    • Bosch, D. D.
    • Webster, T. M.
    • Truman, C. C.
    • Potter, T. L.
  • Source: Journal of Agricultural and Food Chemistry
  • Volume: 59
  • Issue: 14
  • Year: 2011
  • Summary: Intensive glyphosate use has contributed to the evolution and occurrence of glyphosate-resistant weeds that threaten production of many crops. Sustained use of this highly valued herbicide requires rotation and/or substitution of herbicides with different modes of action. Cotton growers have shown considerable interest in the protoporphyrinogen oxidase inhibitor, fomesafen. Following registration for cotton in 2008, use has increased rapidly. Environmental fate data in major use areas are needed to appropriately evaluate risks. Field-based rainfall simulation was used to evaluate fomesafen runoff potential with and without irrigation incorporation in a conventional tillage system (CT) and when conservation tillage (CsT) was practiced with and without cover crop residue rolling. Without irrigation incorporation, relatively high runoff, about 5% of applied, was measured from the CT system, indicating that this compound may present a runoff risk. Runoff was reduced by >50% when the herbicide was irrigation incorporated after application or when used with a CsT system. Data indicate that these practices should be implemented whenever possible to reduce fomesafen runoff risk. Results also raised concerns about leaching and potential groundwater contamination and crop injury due to rapid washoff from cover crop residues in CsT systems. Further work is needed to address these concerns.
  • Authors:
    • Ganesh-Kumar, A.
    • Pullabhotla, H.
    • Prasad, S. K.
  • Issue: 1120
  • Year: 2011
  • Summary: This paper attempts to estimate the future supply and demand for cereals in Nepal. While there has been considerable research in the past examining the agricultural sector in Nepal, to the best of our knowledge there has been no analysis of the supply-demand scenario for food grains in the country. The analysis undertaken in this paper attempts to bridge this gap in the literature by estimating supply and demand models for the three most important cereals in Nepal's food basket: rice, wheat, and maize. The supply projections have been carried out on the basis of a single-crop production function model using data for the period 1995-2008. For estimating the demand function and projecting future demand, data from the Nepal Living Standards Survey II (NLSS II), undertaken in the year 2003/04, are used. The forecasting exercise undertaken here provides a possible picture of rice, wheat, and maize production and demand under business-as-usual, optimistic, and pessimistic scenarios for the years 2010, 2015, 2020, 2025, and 2030. These future projections show a persistent shortfall in the domestic production of rice in Nepal to meet the total demand. Under the pessimistic set of conditions the rice demand in Nepal is projected to be more than double the domestic production in the year 2030. Under the optimistic scenario, production deficit is about 41 percent. In the case of wheat and maize, however, our model estimates a persistent surplus in the domestic production over total domestic demand, going up to as high as 75 percent for wheat and 64 percent for maize under optimistic conditions for the year 2030. Overall, the prime concern for Nepal in ensuring sufficient food supply for the future appears to be with regard to rice, as evidenced by the substantial deficit between the projected supply and demand for rice. Our estimates show that the gap between the domestic production and direct demand by households for rice is likely to vary between 19 percent and 80 percent. It appears that even with accelerated irrigation and increasing fertilizer supply, this deficit in rice would remain. However, technological inputs such as improved seeds, which are not adequately captured in our model, could help increase the yield frontier and help meet a part of this deficit in the future.
  • Authors:
    • Nichols, R. L.
    • Kelton, J. A.
    • Culpepper, S. A.
    • Balkcom, K. S.
    • Price, A. J.
    • Schomberg, H.
  • Source: Journal of Soil and Water Conservation
  • Volume: 66
  • Issue: 4
  • Year: 2011
  • Summary: Conservation tillage reduces the physical movement of soil to the minimum required for crop establishment and production. When consistently practiced as a soil and crop management system, it greatly reduces soil erosion and is recognized for the potential to improve soil quality and water conservation and plant available water. Adoption of conservation tillage increased dramatically with the advent of transgenic, glyphosate-resistant crops that permitted in-season, over-the-top use of glyphosate (N-[phosphonomethyl] glycine), a broad-spectrum herbicide with very low mammalian toxicity and minimal potential for off-site movement in soil or water. Glyphosate-resistant crops are currently grown on approximately 70 million ha (173 million ac) worldwide. The United States has the most hectares (45 million ha [99 million ac]) of transgenic, glyphosate-resistant cultivars and the greatest number of hectares (46 million ha [114 million ac]) in conservation tillage. The practice of conservation tillage is now threatened by the emergence and rapid spread of glyphosate-resistant Palmer amaranth (Amaranthus palmeri [S.]Wats.), one of several amaranths commonly called pigweeds. First identified in Georgia, it now has been reported in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, and Tennessee. Another closely related dioecious amaranth, or pigweed, common waterhemp (Amaranthus rudis Sauer), has also developed resistance to glyphosate in Illinois, Iowa, Minnesota, and. Missouri. Hundreds of thousands of conservation tillage hectares, some currently under USDA Natural Resources Conservation Service conservation program contracts, are at risk of being converted to higher-intensity tillage systems due to the inability to control these glyphosate-resistant Amaranthus species in conservation tillage systems using traditional technologies. The decline of conservation tillage is inevitable without the development and rapid adoption of integrated, effective weed control strategies. Traditional and alternative weed control strategies, such as the utilization of crop and herbicide rotation and integration of high residue cereal cover crops, are necessary in order to sustain conservation tillage practices.
  • Authors:
    • Price, A. J.
    • Balkcom, K. S.
    • Arriaga, F. J.
    • Schwab, E. B.
    • Raper, R. L.
    • Kornecki, T. S.
  • Source: Transactions of the ASABE
  • Volume: 54
  • Issue: 4
  • Year: 2011
  • Summary: The southeastern U.S. has a tremendous potential to grow a biomass crop during winter months when cash crops are not normally produced. These cover crops have proven to be extremely valuable to reduce soil erosion and improve soil quality. However, an opportunity to potentially harvest a portion of the cover crop for bioenergy purposes exists and needs to be considered to maximize the production potential of southeastern soils. An experiment was performed to determine if harvesting these cover crops could adversely affect soil properties or subsequent cash and cover crop yields. The experiment also included the effects of conducting an in-row subsoiling operation at different times of the year Results from cone index measurements indicated that soil strength was significantly increased when the cover crop was harvested and not left on the soil surface to decompose. Not surprisingly, cotton and peanut cash crop yields declined by an average of 9% when the cover crop was harvested. Succeeding cover crop yields were also reduced by 17% due to the harvesting of previous cover crops. Conducting an in-row subsoiling operation in the fall of the year prior to planting the cover crop increased cover crop biomass by more than 18% over spring in-row subsoiling but had little impact on cash crop yields. Recommendations from this study should include a caution to producers who may want to consider their cover crops as a potential bioenergy crop. Reductions in both cash and cover crop production can result if cover crops are harvested instead of left on the surface to enhance soil quality. Additionally, scheduling a necessary in-row subsoiling operation in the fall of the year instead of waiting until the spring will improve cover crop yields.
  • Authors:
    • Mauli, M. M.
    • de Lima, G. P.
    • Pereira Nóbrega, L. H.
    • Rosa, D. M.
  • Source: Semina: Ciências Agrárias (Londrina)
  • Volume: 32
  • Issue: 4
  • Year: 2011
  • Summary: The no-tillage system management is considered as an agricultural system very close to sustainability, since it causes less impact to the environment. The crops rotation, when well managed, includes the use of green manure; and leguminous are included in this system as they bring a number of benefits. This context, the study aimed tested leguminous as cover plants on soil with a no-tillage system regarding the growth, yield and maize seeds quality. This decision-making looks for alternatives that contribute for the agroecosystem sustainability, since they allow rational adoption of green manure in production units. The experiment was carried out in the field with leguminous species dwarf mucuna beans, dwarf pigeon pea and stylosanthes, sown in October 2007, in 4 x 5 m plots, with five replications. At 90 days after the cover crops sowing, the leguminous plants were grazed and corn plants were sown 15 days after grazing on waste. The plants heights were determined during the culture development. At the laboratory, after harvest, the productivity and physiological quality of seeds were determined. The experimental design was completely randomized and the averages were compared by the Scott-Knott test at 5% of significance. At 60 days after the maize crop sowing, the treatments with dwarf mucuna beans and dwarf pigeon pea showed higher heights. The other analyzed parameters did not differ among themselves, showing that the treatments not interfere on the maize crop. Actually, it is an alternative to the integrated management of species concerning the summer green manure and crop rotation in no-tillage system.
  • Authors:
    • Prabhakaran, N. K.
    • Chinnusamy, C.
    • Sangeetha, C.
  • Source: Madras Agricultural Journal
  • Volume: 98
  • Issue: 4/6
  • Year: 2011
  • Summary: A study was carried out to evaluate the effect of early post emergence herbicide, imazethapyr against weeds in irrigated soybean (Glycine max (L.) Merill) at Agricultural Research Station, Bhavanisagar. Weeds, viz., Dactyloctenium aegypticum, Acrach ne racemosa, Cyperus rotundus, Boerhaavia diffusa, Digera arvensis, Parthenium hysterophorous were the dominant weeds in the experimental field. Imazethapyr at 100 and 200 g ha -1 applied on 15 DAS provided 87 to 91% weed control efficiency compared to unweeded control. However, imazethapyr at 200 g ha -1 had slight phytotoxicity on soybean in the initial stages. Higher grain yield of 1645 kg ha -1 was obtained with application of imazethapyr 100 g ha -1.
  • Authors:
    • Prasad, T. V. R.
    • Kumar, V. K. K.
    • Sanjay, M. T.
    • Gowda, P. T.
  • Source: Journal of Crop and Weed
  • Volume: 7
  • Issue: 1
  • Year: 2011
  • Summary: A field experiment was conducted during Kharif 2007 and summer 2008 on sandy loam soil of Hebbal, Bangalore, University of Agricultural Sciences, Bangalore, to know the comparative performance of tank mix application of chlorimuron ethyl (Kloben 25% WP)+quizalofop-p-terfuryl (Pantera 4% EC) on controlling weeds in soybean and seed yield Tank mix combination of chlorimuron ethyl 9 g+quizalofop-p-tefuryl 40 g ai/ha -20 DAS with surfactant (1598 kg/ha) or without surfactant (1518 kg/ha) gave seed yield similar to hand weeding twice (1720 kg/ha), as result of good control of grasses, broad leaf weeds and sedge. Unweeded control lowered the yield by 61% mainly due to severe competition offered by grasses. Thus, use of chlorimuron ethyl 9 g+quizalofop-p-terfuryl 40 g ai/ha+0.2% surfactant (as tank mix) at 20 DAS can be used safely for broad spectrum weed control in irrigated soybean.
  • Authors:
    • Munkhtsetseg, E.
    • Kimura, R.
    • Şaylan, L.
    • Kamichika, M.
  • Source: Theoretical and Applied Climatology
  • Volume: 105
  • Issue: 1/2
  • Year: 2011
  • Summary: In this study, variations in carbon dioxide (CO 2) fluxes resulting from gross primary production (GPP), net ecosystem exchange (NEE), and respiration ( Re) of soybean ( Glycine max L.) were investigated by the Eddy Covariance method during the growing period from June to November 2005 on an irrigated sand field at the Arid Land Research Center, Tottori University in Tottori, Japan. Although climatic conditions were humid and temperate, the soybeans required frequent irrigation because of the low water holding capacity of the sandy soil at the field site. Finally, it has been found that the accumulated NEE, GPP, and Re fluxes of soybean over 126 days amount to -93, 319, and 226 gC m -2, respectively. Furthermore, the average ratio of GPP to Re was 1.4 and the average ratio of NEE to GPP was about -0.29 for the growth period of soybean. Daily maximum NEE of -3.8 gC m -2 occurred when LAI was 1.1.