• Authors:
    • Kumar, P.
    • Yadav, S. K.
    • Kumar, M.
    • Rinwa, R . S.
  • Source: Haryana Journal of Horticultural Sciences
  • Volume: 35
  • Issue: 3/4
  • Year: 2006
  • Summary: An experiment was conducted during 2003-04 and 2004-05 to study the nitrogen, phosphorus and potassium uptake by different cropping systems in semiarid tract of Haryana, India. The experiment comprised 7 cropping systems, viz., pearl millet-wheat, pearl millet-mustard, soyabean-wheat-cowpea, sorghum-wheat, pearl millet-potato-green gram, pearl millet-field pea-maize, and cotton-wheat. The uptake of nitrogen, phosphorus and potassium by the crops varied among different cropping systems. The nutrient uptake was higher in high yielding cropping systems. The nutrients uptake was highest in pearl millet-potato-green gram cropping system.
  • Authors:
    • Healy, K.
    • Reichstein, I.
    • Murray, B.
  • Source: 9th International Working Conference on Stored Product Protection -- New Chemicals and Food Residues PS3-2-6324
  • Year: 2006
  • Summary: The National Residue Survey (NRS) is an operational unit of the Australian Government Department of Agriculture, Fisheries and Forestry. NRS has managed and operated residue testing programs (including meat products and grains) for over 40 years. The NRS Grains Residue Testing Program is fully industry funded via a 0.015% ad valorem levy on grain growers. This Residue Testing Program complements that undertaken by grain marketers/handlers from grower receivals to bulk storage. Noting that NRS does not have a regulatory role, the Grains Program is viewed as providing independent verification of the residue status of Australian grain at the point of out-turn for export and for receival at grain processors such as flour mills. The Grains Program covers wheat, barley, oat, sorghum, canola, field pea, chickpea and lupin. By 2007, it is expected to extend to all tradeable grains including lentil, soybean, maize, triticale, sunflower, mung bean and faba/broad bean. Each year, the Grains Program is independently reviewed and a prospective monitoring plan circulated to the Grains Council of Australia and State affiliates, and peak grain industry bodies for endorsement. The Grains Program monitoring plan specifies that approximately 5,500 grain samples are collected per annum from export shipments and containers, flour mills, feedmills, feedlots and maltsters. About 4,000 samples are collected from export shipments where every hatch of every ship from every Australian grain export terminal is sampled during loading. The monitoring plan stipulates that samples be sent to an accredited proficiency-tested laboratory and residue testing results reported to the grain marketer/handler within 14 days of sample collection. Grain samples are subjected to a chemical screen covering a range of insecticides, fungicides and environmental contaminants. These residue testing results are reported against Australian MRLs established by Food Standards Australia and New Zealand.
  • Authors:
    • Whitehead, W. F.
    • Singh, B. P.
    • Sainju, U. M.
    • Wang, S.
  • Source: Journal of Environmental Quality
  • Volume: 35
  • Issue: 4
  • Year: 2006
  • Summary: Soil carbon (C) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant C inputs and their rate of mineralization. We examined the influence of four cover crops (legume [hairy vetch (Vicia villosa Roth)], non-legume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)) and three nitrogen (N) fertilization rates (0, 60 to 65, and 120 to 130 kg N ha(-1)) on C inputs from cover crops, cotton (Gossypium hirsutum L.), and sorghum [Sorghum bicolor (L.) Moench)], and soil organic carbon (SOC) at the 0- to 120-cm depth in tilled and nontilled areas. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic Plinthic Paleudults) from 1999 to 2002 in central Georgia. Total C inputs to the soil from cover crops, cotton, and sorghum from 2000 to 2002 ranged from 6.8 to 22.8 Mg ha(-1). The SOC at 0 to 10 cm fluctuated with C input from October 1999 to November 2002 and was greater from cover crops than from weeds in no-tilled plots. In contrast, SOC values at 10 to 30 em in no-tilled and at 0 to 60 cm in chisel-tilled plots were greater for biculture than for weeds. As a result, C at 0 to 30 cm was sequestered at rates of 267, 33, -133, and -967 kg C ha(-1) yr(-1) for biculture, rye, vetch, and weeds, respectively, in the no-tilled plot. In strip-tilled and chisel-tilled plots, SOC at 0 to 30 cm decreased at rates of 233 to 1233 kg C ha(-1) yr(-1). The SOC at 0 to 30 cm increased more in cover crops with 120 to 130 kg N ha(-1) yr(-1) than in weeds with 0 kg N ha(-1) yr(-1) regardless of tillage. In the subtropical humid region of the southeastern United States, cover crops and N fertilization can increase the amount of C input and storage in tilled and nontilled soils, and hairy vetch and rye biculture was more effective in sequestering C than monocultures or no cover crop.
  • Authors:
    • Raundal, P. U.
    • Kambale, A. B.
    • Chaudhari, P. M.
    • Chitodkar, S. S.
  • Source: International Journal of Agricultural Sciences
  • Volume: 2
  • Issue: 2
  • Year: 2006
  • Summary: A study was conducted in Maharashtra, India during 2002, 2003 and 2004 under rainfed conditions to evaluate the effect of intercropping with pigeon pea (cv. BSMR-78), sorghum (cv. CHS-14) and cotton (cv. Y-1) on the productivity of soyabean (cultivars JS-335 and MACS-124). The spacings were 30 * 10, 65 * 20, 45 * 15 and 45 * 22.5 cm for soyabean, pigeon pea, sorghum and cotton, respectively, under soyabean intercropping, at 3:1 row proportion. Soyabean + pigeon pea produced the highest soyabean equivalent yield (24.06 q/ha), gross monetary returns (Rs. 30 322/ha), net monetary returns (Rs. 20 010/ha), land equivalent ratio (1.38) and benefit:cost ratio (2.92).
  • Authors:
    • Hons, F.
    • Wright, A.
  • Source: Biology and Fertility of Soils
  • Volume: 41
  • Issue: 2
  • Year: 2005
  • Summary: Management practices, such as no tillage (NT) and intensive cropping, have potential to increase C and N sequestration in agricultural soils. The objectives of this study were to investigate the impacts of conventional tillage (CT), NT, and cropping intensity on soil organic C (SOC) and N (SON) sequestration and on distribution within aggregate-size fractions in a central Texas soil after 20 years of treatment imposition. Tillage regime and cropping sequence significantly impacted both SOC and SON sequestration. At 0-5 cm, NT increased SOC storage compared to CT by 33% and 97% and SON storage by 25% and 117% for a sorghum/wheat/soybean (SWS) rotation and a continuous sorghum monoculture, respectively. Total SOC and SON storage at both 0-5 and 5-15 cm was greater for SWS than continuous sorghum regardless of tillage regime. The majority of SOC and SON storage at 0-5 cm was observed in 250-m to 2-mm aggregates, and at 5-15 cm, in the >2-mm and 250-m to 2-mm fractions. Averaged across cropping sequences at 0-5 cm, NT increased SOC storage compared to CT by 212%, 96%, 0%, and 31%, and SON storage by 122%, 92%, 0%, and 37% in >2-mm, 250-m to 2-mm, 53- to 250-m, and
  • Authors:
    • Hons, F.
    • Wright, A.
  • Source: Soil Science Society of America Journal
  • Volume: 69
  • Issue: 1
  • Year: 2005
  • Summary: No-tillage (NT) has the potential to enhance C and N sequestration in agricultural soils of the southern USA, but results may vary with crop species. The objectives of this study were to investigate the impacts of NT, conventional tillage (CT), and crop species on soil organic carbon (SOC) and nitrogen (SON) sequestration and distribution within aggregate-size fractions in a central Texas soil after 20 yr of management. No-tillage increased SOC over CT at the 0- to 5-cm depth by 97, 47, and 72%, and SON by 117, 56, and 44% for continuous grain sorghum [ Sorghum bicolor (L.) Moench], wheat ( Triticum aestivum L.), and soyabean [ Glycine max (L.) Merr.], respectively. Crop species had significant impacts on SOC and SON sequestration. On average, the wheat monoculture had greater SOC (9.23 Mg C ha -1) at the 0- to 5-cm depth than sorghum (6.75 Mg C ha -1) and soyabean (7.05 Mg C ha -1). No-tillage increased the proportion of >2-mm and 250-m to 2-mm macroaggregate fractions in soil compared with CT. At the 0- to 5-cm depth, NT increased SOC compared with CT by 158% in macroaggregate fractions, but only 40% in 2-mm, 250-m to 2-mm, 53- to 250-m, and
  • Authors:
    • Hons, F.
    • Wright, A.
  • Source: Soil & Tillage Research
  • Volume: 84
  • Issue: 1
  • Year: 2005
  • Summary: No tillage (NT) and increased cropping intensity have potential for enhanced C and N sequestration in agricultural soils. The objectives of this study were to investigate the impacts of conventional tillage (CT), NT, and multiple cropping sequences on soil organic C (SOC) and N (SON) sequestration and on distribution within aggregate-size fractions in a southcentral Texas soil at the end of 20 years of treatment imposition. Soil organic C and SON sequestration were significantly greater under NT than CT for a grain sorghum [ Sorghum bicolor (L.) Moench]/wheat ( Triticum aestivum L.)/soybean [ Glycine max (L.) Merr.] rotation (SWS), a wheat/soybean doublecrop (WS), and a continuous wheat monoculture (CW) at 0-5 cm and for the SWS rotation at 5-15 cm. At 0-5 cm, NT increased SOC storage compared to CT by 62, 41, and 47% and SON storage by 77, 57, and 56%, respectively, for SWS, WS, and CW cropping sequences. Increased cropping intensity failed to enhance SOC or SON sequestration at either soil depth compared to the CW monoculture. No-tillage increased the proportion of macroaggregates (>2 mm) at 0-5 cm but not at 5-15 cm. The majority of SOC and SON storage under both CT and NT was observed in the largest aggregate-size fractions (>2 mm, 250 m to 2 mm). The use of NT significantly improved soil aggregation and SOC and SON sequestration in surface but not subsurface soils.
  • Authors:
    • Lal, R.
  • Source: Environment International
  • Volume: 31
  • Issue: 4
  • Year: 2005
  • Summary: Reducing and off-setting anthropogenic emissions of CO, and other greenhouse gases (GHGs) are important strategies of mitigating the greenhouse effect. Thus, the need for developing carbon (C) neutral and renewable sources of energy is more than ever before. Use of crop residue as a possible source of feedstock for bioenergy production must be critically and objectively assessed because of its positive impact on soil C sequestration.. soil quality maintenance and ecosystem functions. The amount of crop residue produced in the US is estimated at 367x10(6) Mg/year for 9 cereal crops, 450x10(6) Mg/year for 14 cereals and legumes, and 488x10(6) Mg/year for 21 crops. The amount of crop residue produced in the world is estimated at 2802x10(6) Mg/year for cereal crops, 3107x10(6) Mg/year for 17 cereals and legumes, and 3758x10(6) Mg/year for 27 food crops. The fuel value of the total annual residue produced is estimated at 1.5x10(15) kcal, about 1 billion barrels (bbl) of diesel equivalent, or about 8 quads for the US; and 11.3x10(15) kcal, about 7.5 billion bbl of diesel or 60 quads for the world. However, even a partial removal (30-40%) of crop residue from land can exacerbate soil erosion hazard, deplete the SOC pool, accentuate emission of CO, and other GHGs from soil to the atmosphere, and exacerbate the risks of global climate change. Therefore, establishing bioenergy plantations of site-specific species with potential of producing 10-15 Mg biomass/year is an option that needs to be considered. This option will require 40-60 million hectares of land in the US and about 250 million hectares worldwide to establish bioenergy plantations. (c) 2004 Elsevier Ltd. All rights reserved.
  • Authors:
    • Schuman, G. E.
    • Gollany, H. T.
    • Ellert, B. H.
    • Reeder, J. D.
    • Morgan, J. A.
    • Liebig, M. A.
  • Source: Soil & Tillage Research
  • Volume: 83
  • Issue: 1
  • Year: 2005
  • Summary: Concern over human impact on the global environment has generated increased interest in quantifying agricultural contributions to greenhouse gas fluxes. As part of a research effort called GRACEnet (Greenhouse Gas Reduction through Agricultural Carbon Enhancement Network), this paper summarizes available information concerning management effects on soil organic carbon (SOC) and carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) fluxes in cropland and rangeland in northwestern USA and western Canada, a region characterized by its inherently productive soils and highly variable climate. Continuous cropping under no-tillage in the region increased SOC by 0.27 ± 0.19 Mg C ha-1 yr-1, which is similar to the Intergovernmental Panel on Climate Change (IPCC) estimate for net annual change in C stocks from improved cropland management. Soil organic C sequestration potential for rangelands was highly variable due to the diversity of plant communities, soils, and landscapes, underscoring the need for additional long-term C cycling research on rangeland. Despite high variability, grazing increased SOC by 0.16 ± 0.12 Mg C ha-1 yr-1 and converting cropland or reclaimed mineland to grass increased SOC by 0.94 ± 0.86 Mg C ha-1 yr-1. Although there was generally poor geographical coverage throughout the region with respect to estimates of N2O and CH4 flux, emission of N2O was greatest in irrigated cropland, followed by non-irrigated cropland, and rangeland. Rangeland and non-irrigated cropland appeared to be a sink for atmospheric CH4, but the size of this sink was difficult to determine given the few studies conducted. Researchers in the region are challenged to fill the large voids of knowledge regarding CO2, N2O, and CH4 flux from cropland and rangeland in the northwestern USA and western Canada, as well as integrate such data to determine the net effect of agricultural management on radiative forcing of the atmosphere.
  • Authors:
    • Blum, A.
  • Source: Australian Journal of Agricultural Research
  • Volume: 56
  • Issue: 11
  • Year: 2005