• Authors:
    • Bonta, J. V.
    • Owens, L. B.
    • Shipitalo, M. J.
    • Rogers, S.
  • Source: Journal of Environmental Quality
  • Volume: 40
  • Issue: 1
  • Year: 2011
  • Summary: Winter application of manure poses environmental risks. Seven continuous corn, instrumented watersheds (approximately 1 ha each) at the USDA-ARS North Appalachian Experimental Watershed research station near Coshocton, Ohio were used to evaluate the environmental impacts of winter manure application when using some of the Ohio Natural Resources Conservation Service recommendations. For 3 yr on frozen, sometimes snow-covered, ground in January or February, two watersheds received turkey litter, two received liquid swine manure, and three were control plots that received N fertilizer at planting (not manure). Manure was applied at an N rate for corn; the target level was 180 kg N ha(-1) with a 30-m setback from the application area to the bottom of each watershed. Four grassed plots (61 x 12 m) were used for beef slurry application (9.1 Mg ha(-1) wet weight); two plots had 61 x 12 m grassed filter areas below them, and two plots had 30 x 12 m filter areas. There were two control plots. Nutrient concentrations were sometimes high, especially in runoff soon after application. However, most events with high concentrations occurred with low flow volumes; therefore, transport was minimal. Applying manure at the N rate for crop needs resulted in excess application of P. Elevated P losses contributed to a greater potential of detrimental environmental impacts with P than with N. Filter strips reduced nutrient concentrations and transport, but the data were too limited to compare the effectiveness of the 30- and 61-m filter strips. Winter application of manure is not ideal, but by following prescribed guidelines, detrimental environmental impacts can be reduced.
  • 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:
    • Pepo, P.
  • Source: Cereal Research Communications
  • Volume: 39
  • Issue: 1
  • Year: 2011
  • Summary: The interactions of ecological conditions, genotypes and agrotechnical elements determine the yield quantity, quality and stability in cereal (wheat, maize) production. The applied input-level can modify the adaptive capacity of crop models to ecological conditions. The effects of agrotechnical elements (crop rotation, fertilization, irrigation, crop protection, plant density) were studied in the long-term experiment on chernozem soil. Our scientific results proved that the high yields and good yield-stability were obtained in the input-intensive crop models, so these models had better adaptive capacity, high yield and resilience. Maize had lower ecological adaptive ability than winter wheat. The optimalization of agrotechnical elements reduces the harmful climatic effects so we can increase the yield and yield stability of cereals agro-ecosystems. The yields of wheat varied between 2 and 7 t ha -1 in extensive and 8 and 10 t ha -1 in intensive crop models and the yields of maize ranged between 2 and 11 t ha -1 and 10 and 15 t ha -1, respectively.
  • 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:
    • Thorp, K. R.
    • Malone, R. W.
    • Helmers, M. J.
    • Qi, Z.
  • Source: Transactions of the ASABE
  • Volume: 54
  • Issue: 5
  • Year: 2011
  • Summary: Planting winter cover crops into corn-soybean rotations is a potential approach for reducing subsurface drainage and nitrate-nitrogen (NO(3)-N.) loss. However, the long-term impact of this practice needs investigation. We evaluated the RZWQM2 model against comprehensive field data (2005-2009) in Iowa and used this model to study the long-term (1970-2009) hydrologic and nitrogen cycling effects of a winter cover crop within a corn-soybean rotation. The calibrated RZWQM2 model satisfactorily simulated crop yield, biomass, and N uptake with percent error (PE) within +/- 15% and relative root mean square error (RRMSE) 0.50, ratio of RMSE to standard error (RSR)
  • Authors:
    • Pederson, C. H.
    • Christianson, R. D.
    • Helmers, M. J.
    • Qi, Z.
  • Source: Journal of Environmental Quality
  • Volume: 40
  • Issue: 5
  • Year: 2011
  • Summary: Nitrate-nitrogen (NO(3)-N) loading to surface water bodies from subsurface drainage is an environmental concern in the midwestern United States. The objective of this study was to investigate the effect of various land covers on NO(3)-N loss through subsurface drainage. Land-cover treatments included (i) conventional corn (Zea mays L.) (C) and soybean [Glycine max (L.) Merr.] (S); (ii) winter rye (Secale cereale L.) cover crop before corn (rC) and before soybean (rS); (iii) kura clover (Trifolium ambiguum M. Bieb.) as a living mulch for corn (kC); and (iv) perennial forage of orchardgrass (Dactylis glomerata L.) mixed with clovers (PF). In spring, total N uptake by aboveground biomass of rye in rC, rye in rS, kura clover in kC, and grasses in PF were 14.2, 31.8, 87.0, and 46.3 kg N ha(-1), respectively. Effect of land covers on subsurface drainage was not significant. The NO(3)-N loss was significantly lower for kC and PF than C and S treatments (p
  • Authors:
    • Kaleita, A. L.
    • Helmers, M. J.
    • Qi, Z.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 4
  • Year: 2011
  • Summary: Modification of land cover systems is being studied in subsurface drained Iowa croplands due to their potential benefits in increasing soil water and nitrogen depletion thus reducing drainage and NO(3)-N loss in the spring period. The objective of this study was to evaluate the impacts of modified land covers on soil water dynamics. In each individual year, modified land covers including winter rye-corn (rC), winter rye-soybean (rS), kura clover as a living mulch for corn (kC), and perennial forage (PF), as well as conventional corn (C) and soybean (S), were grown in subsurface drained plots in north-central Iowa. Results showed that subsurface drainage was not reduced under modified land covers in comparison to conventional corn and soybean. Soil water storage (SWS) was significantly reduced by PF treatments during the whole growing seasons and by kC during May through July when compared to the cropping system with corn or soybean only (p
  • 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:
    • Isla, R.
    • Salmeron, M.
    • Cavero, J.
  • Source: Field Crops Research
  • Volume: 123
  • Issue: 2
  • Year: 2011
  • Summary: Under semiarid Mediterranean conditions irrigated maize has been associated to diffuse nitrate pollution of surface and groundwater. Cover crops grown during winter combined with reduced N fertilization to maize could reduce N leaching risks while maintaining maize productivity. A field experiment was conducted testing two different cover crop planting methods (direct seeding versus seeding after conventional tillage operations) and four different cover crops species (barley, oilseed rape, winter rape, and common vetch), and a control (bare soil). The experiment started in November 2006 after a maize crop fertilized with 300 kg N ha(-1) and included two complete cover crop-maize rotations. Maize was fertilized with 300 kg N ha(-1) at the control treatment, and this amount was reduced to 250 kg N ha(-1) in maize after a cover crop. Direct seeding of the cover crops allowed earlier planting dates than seeding after conventional tillage, producing greater cover crop biomass and N uptake of all species in the first year. In the following year, direct seeding did not increase cover crop biomass due to a poorer plant establishment. Barley produced more biomass than the other species but its N concentration was much lower than in the other cover crops, resulting in higher C:N ratio (> 26). Cover crops reduced the N leaching risks as soil N content in spring and at maize harvest was reduced compared to the control treatment. Maize yield was reduced by 4 Mg ha(-1) after barley in 2007 and by 1 Mg ha(-1) after barley and oilseed rape in 2008. The maize yield reduction was due to an N deficiency caused by insufficient N mineralization from the cover crops due to a high C:N ratio (barley) or low biomass N content (oilseed rape) and/or lack of synchronization with maize N uptake. Indirect chlorophyll measurements in maize leaves were useful to detect N deficiency in maize after cover crops. The use of vetch, winter rape and oilseed rape cover crops combined with a reduced N fertilization to maize was efficient for reducing N leaching risks while maintaining maize productivity. However, the reduction of maize yield after barley makes difficult its use as cover crop. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Amarasekera, P.
    • Sangakkara, U. R.
    • Stamp, P.
  • Source: Acta Agronomica Hungarica
  • Volume: 59
  • Issue: 2
  • Year: 2011
  • Summary: Maize is the most important upland cereal in tropical Asia, grown in both major and minor seasons under rainfed conditions. Due to the inadequate rainfall in the minor season, the crop is subjected to water stress, and irrigation helps to produce high yields. Smallholders who grow maize on flat beds in their allotments often use surface flood irrigation whenever irrigation water is available, which leads in most instances to inefficient use of this valuable resource. A field study was carried out over two minor seasons in Sri Lanka to determine the impact of different schedules of irrigation, developed on the basis of time intervals (3-, 7-, 14- or 21-day intervals or no irrigation as a control), which can easily be practised by smallholders, on the root development, shoot growth, seed yield and water use efficiency of maize. Irrigation at 3-day intervals produced fine roots in the top layers of the soil. Increasing the time interval between irrigation schedules to 7, 14 or 21 days reduced the percentage of fine roots, but developed more, heavier roots in the lower soil layers, as determined by root length densities (RLD) and root weight densities (RWD). Longer irrigation intervals or lack of irrigation resulted in a smaller number of heavier roots in the soil profile. The leaf water potential was affected to a greater degree than shoot water content or relative water content. The seed yield and harvest index were highest when maize was irrigated at 7-day intervals. In contrast, irrigation water use efficiency (IWUE) was highest at an irrigation interval of 14 days. The potential for optimizing water use in surface irrigation in flat beds while obtaining high yields in a tropical Asian minor season, when maize is subjected to moisture stress under smallholding conditions, is presented on the basis of this study.