• Authors:
    • Bandyopadhyay, K. K.
    • Wanjari, R. H.
    • Manna, M. C.
    • Misra, A. K.
    • Mohanty, M.
    • Rao, A. S.
    • Ghosh, P. K.
  • Source: Journal of Sustainable Agriculture
  • Volume: 30
  • Issue: 1
  • Year: 2007
  • Summary: This article deals with the beneficial effect of important legumes on increasing productivity and nutrient use efficiency in various systems. Sorghum, pearl millet, maize, and castor are mainstay in dry lands and marginal and sub-marginal lands. Sorghum yield increased when sown after cowpea, green gram, and groundnut. Grain legumes like groundnut or cowpea provide an equivalent to 60 kg N ha on the subsequent crop of pearl millet. Various studies have shown that among legume/cereal intercropping system, the combination of maize/pigeon pea is considered to be highly suitable with a minimum competition for nutrients, while legume/legume intercropping system, pigeon pea/groundnut system is the most efficient one in terms of resource use-efficiency. In alley cropping system, Leucaena leucocephala (Subabul) prunings provide N to the extent of 75 kg, which benefits the intercrop castor and sorghum. Nitrogen economy through intercropped legume is still a researchable issue because the key point for leguminous crop grown in intercropping system is the problem of nodulation. Incorporation of whole plant of summer green gram/black gram into soil (after picking pods) before transplanting rice resulted in the economizing (40-60 kg N ha -1, 30 kg P 2O 5, and 15 kg K 2O per ha) of rice in rice-wheat system. Similarly, 6-8 weeks old green manure crop of sunhemp or dhaincha accumulates approximately 3-4 t ha -1 dry matter and 100-120 kg N ha -1 which, when incorporated in situ, supplements up to 50% of the total N requirement of rice. Legumes with indeterminate growth are more efficient in N 2 fixation than determinate types. Fodder legumes in general are more potent in increasing the productivity of succeeding cereals. The carryover of N for succeeding crops may be 60-120 kg in berseem, 75 kg in Indian clover, 75 kg in cluster bean, 35-60 kg in fodder cowpea, 68 kg in chickpea, 55 kg in black gram, 54-58 kg in groundnut, 50-51 kg in soyabean, 50 kg in Lathyrus, and 36-42 kg per ha in pigeon pea. Direct and residual effect of partially acidulated material and mixture of rock phosphate + single superphosphate were observed to be better when these were applied to green gram in winter season than to rice in rainy season simply because of legume effect.
  • Authors:
    • Lachnicht-Weyers, S. L.
    • Tillman, P. G.
    • Whitehead, P. G.
    • Singh, B. P.
    • Schomberg, H. H.
    • Sainju, U. M.
  • Source: Soil & Tillage Research
  • Volume: 96
  • Year: 2007
  • Summary: Cover crops may influence soil carbon (C) sequestration and microbial biomass and activities by providing additional residue C to soil. We examined the influence of legume [crimson clover (Trifolium incarnatum L.)], nonlegume [rye (Secale cereale L.)], blend [a mixture of legumes containing balansa clover (Trifolium michelianum Savi), hairy vetch (Vicia villosa Roth), and crimson clover], and rye + blendfmixture cover crops on soil C fractions at the 0-150 mm depth from 2001 to 2003. Active fractions of soil C included potential C mineralization (PCM) and microbial biomass C (MBC) and slow fraction as soil organic C (SOC). Experiments were conducted in Dothan sandy loam (fine-loamy, kaolinitic, thermic, Plinthic Kandiudults) under dryland cotton (Gossypium hirsutum L.) in central Georgia and in Tifton loamy sand (fine-loamy, siliceous, thermic, Plinthic Kandiudults) under irrigated cotton in southern Georgia, USA. Both dryland and irrigated cotton were planted in strip tillage system where planting rows were tilled, thereby leaving the areas between rows untilled. Total aboveground cover crop and cotton C in dryland and irrigated conditions were 0.72-2.90 Mg C ha-1 greater in rye + blend than in other cover crops in 2001 but was 1.15-2.24 Mg C ha-1 greater in rye than in blend and rye + blend in 2002. In dryland cotton, PCM at 50-150 mm was greater in June 2001 and 2002 than in January 2003 but MBC at 0-150 mm was greater in January 2003 than in June 2001. In irrigated cotton, SOC at 0-150 mm was greater with rye + blend than with crimson clover and at 0-50 mm was greater in March than in December 2002. The PCM at 0-50 and 0-150 mm was greater with blend and crimson clover than with rye in April 2001 and was greater with crimson clover than with rye and rye + blend in March 2002. The MBC at 0-50 mm was greater with rye than with blend and crimson clover in April 2001 and was greater with rye, blend, and rye + blend than with crimson clover in March 2002. As a result, PCM decreased by 21-24 g CO2-C ha-1 d-1 but MBC increased by 90-224 g CO2-C ha-1 d-1 from June 2001 to January 2003 in dryland cotton. In irrigated cotton, SOC decreased by 0.1-1.1 kg C ha-1 d-1, and PCM decreased by 10 g CO2-C ha-1 d-1 with rye to 79 g CO2-C ha-1 d-1 with blend, but MBC increased by 13 g CO2-C ha-1 d-1 with blend to 120 g CO2-C ha-1 d-1 with crimson clover from April 2001 to December 2002. Soil active C fractions varied between seasons due to differences in temperature, water content, and substrate availability in dryland cotton, regardless of cover crops. In irrigated cotton, increase in crop C input with legume + nonlegume treatment increased soil C storage and microbial biomass but lower C/N ratio of legume cover crops increased C mineralization and microbial activities in the spring.
  • Authors:
    • Voroney, P.
    • Kay, B.
    • Warland, J.
    • von Bertoldi, P.
    • Parkin, G.
    • Wagner-Riddle, C.
    • Jayasundara, S.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 79
  • Issue: 2
  • Year: 2007
  • Summary: Best management practices are recommended for improving fertilizer and soil N uptake efficiency and reducing N losses to the environment. Few year- round studies quantifying the combined effect of several management practices on environmental N losses have been carried out. This study was designed to assess crop productivity, N uptake from fertilizer and soil sources, and N losses, and to relate these variables to the fate of fertilizer 15N in a corn ( Zea mays L.)- soybean ( Glycine max L.)- winter wheat ( Triticum aestivum L.) rotation managed under Best Management ( BM) compared with conventional practices ( CONV). The study was conducted from May 2000 to October 2004 at Elora, Ontario, Canada. Cumulative NO3 leaching loss was reduced by 51% from 133 kg N ha(-1) in CONV to 68 kg N ha(-1) in BM. About 70% of leaching loss occurred in corn years with fertilizer N directly contributing 11 - 16% to leaching in CONV and < 4% in BM. High soil derived N leaching loss in CONV, which occurred mostly ( about 80%) during November to April was attributable to 45 - 69% higher residual soil derived mineral N left at harvest, and on-going N mineralization during the over-winter period. Fertilizer N uptake efficiency ( FNUE) was higher in BM ( 61% of applied) than in CONV ( 35% of applied) over corn and wheat years. Unaccounted gaseous losses of fertilizer N were reduced from 27% of applied in CONV to 8% of applied in BM. Yields were similar between BM and CONV ( for corn: 2000 and 2003, wheat: 2002, soybean: 2004) or higher in BM ( soybean: 2001). Results indicated that the use of judicious N rates in synchrony with plant N demand combined with other BMP ( no- tillage, legume cover crops) improved FNUE by corn and wheat, while reducing both fertilizer and soil N losses without sacrificing yields.
  • Authors:
    • Burgener, P. A.
    • Felter, D. G.
    • Nielsen, D. C.
    • Lyon, D. J.
  • Source: Agronomy Journal
  • Volume: 99
  • Issue: 2
  • Year: 2007
  • Summary: Winter wheat (Triticum aestivum L.) is the foundation of dryland cropping systems in the Central Great Plains. The objective of this study was to quantify the effects of four short-season spring-planted crops used to replace summer fallow on the subsequent winter wheat crop. Wheat was seeded into four crop stubbles [spring triticale (xTriticosecale Wittmack), dry pea (Pisum sativum L.), foxtail millet (Setaria italica L. Beauv.), and proso millet (Panicum miliaceum L.)] at sites near Akron, CO, and Sidney, NE, in the fall of 2004 and 2005. These summer fallow replacement crops were planted into silt loam soils at three different soil water levels at planting (low, medium, and high). Winter wheat water use was 3.6 cm greater, and grain yield was 662 kg ha-1 greater in the high water treatment compared with the low water treatment averaged across all sites and years. Winter wheat used an average of 4.3 cm more water following early planted summer crops (triticale and dry pea) than after late planted summer crops (foxtail and proso millet), but this increased water use did not consistently translate into increased grain yield as a result of terminal drought at Sidney in 2006. The high water treatment always had a positive net return. The high cost of pea seed ($3.30 kg-1, USD) strongly reduced profitability. The flexible summer fallow cropping system appears to be most applicable when using short-duration summer annual forage crops such as triticale and foxtail millet.
  • Authors:
    • Hao,X.
    • Kravchenko,A. N.
  • Source: Agronomy Journal
  • Volume: 99
  • Issue: 1
  • Year: 2007
  • Summary: Management practice and soil texture are known to affect soil C. Relatively little information exists, however, on interactions between textural and management effects. The objective of this study was to evaluate management effects on soil total C along a textural gradient in well-drained Typic Hapludalfs in southwest Michigan. Three management practices considered in this study were conventional tillage (CT) and no-till (NT) both with conventional chemical inputs, and conventional tillage with leguminous cover crops and no chemical inputs (CT-cover). Four replicate plots were sampled for each practice, with approximately 100 soil samples taken at the 0- to 5-cm depth in each plot. In all management practices, the relationships of total C and N with clay + silt varied depending on the range of clay + silt values, with regression slopes at clay + silt 570 g kg-1. Total C in the CT-cover and NT treatments was higher than that in the CT treatment across the whole range of studied textures; however, a greater difference in total C between NT and CT occurred at greater clay + silt contents. Total C in the CT-cover and NT treatments were not different when clay + silt was 600 g kg-1. The results indicate that the potential for C accumulation in surface soils via NT treatment depends on soil texture.
  • Authors:
    • Tourdonnet, S. D.
    • Carof, M.
    • Coquet, Y.
    • Hallaire, V.
    • Roger-Estrade, J.
  • Source: Soil Use and Management
  • Volume: 23
  • Issue: 3
  • Year: 2007
  • Summary: We studied soil hydraulic conductivity (K) and porosity in five combinations of soil tillage and cover crop management systems. Treatments were winter wheat (Triticum aestivum L.) grown on a conventionally tilled soil (CT), on a no-till soil (NT), and on an NT with three different cover crops: red fescue (Festuca rubra L.; Fr), bird's-foot-trefoil (Lotus corniculatus L.; Lc) and alfalfa (Medicago sativa L.; Ms). Measurements were made on a loamy soil in Grignon, France, in November 2004, May 2005 and October 2005. K and mean size of hydraulically active pores were measured in situ at three water potentials (22120.6, 22120.2 and 22120.05 kPa) at the soil surface and at 10 cm depth. In November 2004 and May 2005, pore space was described using 2D image analysis of pores on undisturbed soil samples in the 0201310 cm layer and in the 10201320 cm layer. The major differences were caused by soil tillage that created two heterogeneous soil layers and increased K in the 0201310 cm layer relative to NT. The effects of cover crop on K and porosity were not affected by the root type: there were no major differences between the grass cover crop (fibrous-root type) and the leguminous ones (tap-root type). However, we recorded larger functional pores and more tubules in the no-till treatments with a cover crop, compared with the no-till treatment without cover crop; this was probably the result of root activity. Although these changes generally did not result in larger values of K, they participated in the maintenance of soil structure and K over time.
  • Authors:
    • King, A. J.
    • Cooper, J. E.
    • Strong, W. M.
    • Dalal, R. C.
  • Source: Australian Journal of Experimental Agriculture
  • Volume: 47
  • Issue: 7
  • Year: 2007
  • Summary: No-tillage (NT) practice, where straw is retained on the soil surface, is increasingly being used in cereal cropping systems in Australia and elsewhere. Compared to conventional tillage (CT), where straw is mixed with the ploughed soil, NT practice may reduce straw decomposition, increase nitrogen immobilisation and increase organic carbon in the soil. This study examined N-15-labelled wheat straw ( stubble) decomposition in four treatments (NT v. CT, with N rates of 0 and 75 kg/ha. year) and assessed the tillage and fertiliser N effects on mineral N and organic C and N levels over a 10-year period in a field experiment. NT practice decreased the rate of straw decomposition while fertiliser N application increased it. However, there was no tillage practice x N interaction. The mean residence time of the straw N in soil was more than twice as long under the NT (1.2 years) as compared to the CT practice (0.5 years). In comparison, differences in mean residence time due to N fertiliser treatment were small. However, tillage had generally very little effect on either the amounts of mineral N at sowing or soil organic C (and N) over the study period. While application of N fertiliser increased mineral N, it had very little effect on organic C over a 10-year period. Relatively rapid decomposition of straw and short mean residence time of straw N in a Vertisol is likely to have very little long-term effect on N immobilisation and organic C level in an annual cereal cropping system in a subtropical, semiarid environment. Thus, changing the tillage practice from CT to NT may not necessitate additional N requirement unless use is made of additional stored water in the soil or mineral N loss due to increased leaching is compensated for in N supply to crops.
  • Authors:
    • Thakare, R.
    • Gupta, V. R.
  • Source: Indian Journal of Agricultural Research
  • Volume: 41
  • Issue: 4
  • Year: 2007
  • Summary: Effect of irrigated and rainfed cropping systems on carbon and nitrogen mineralization was studied. Maximum C and N mineralization observed under irrigated cropping systems than rainfed. Sorghum-chickpea-groundnut showed highest mineralization under irrigated condition. While monocropping and intercropping with legumes enhances the rate of mineralization under rainfed situation. Mineralization was found to be highest during grand growth period of crops. Application of integrated nutrient supply increased C and N mineralization as compared to their individual application. The FYM+wheat straw+green manuring application augmented the mineralization under soybean-wheat crop sequence.
  • Authors:
    • Tiwary ,P.
    • Manual, D. K.
    • Prasad, J.
    • Hajare, T. N.
    • Challa, O.
  • Source: Agropedology
  • Volume: 17
  • Issue: 1
  • Year: 2007
  • Summary: An experiment was conducted to compare the production potential and economic feasibility of various crop combinations, i.e. cotton (cv. Anjali 561) intercropped with cowpea, urd bean and dhaincha, and soyabean (cv. JS 335) intercropped with maize, sorghum and pigeon pea, under rainfed farming conditions in Nagpur, Maharashtra, India, during 2002-04. The soils of the area are 22-24 cm deep (underlain by murrum/saprolite up to 40-45 cm), well-drained (Lithic Ustorthents) and occur on 1-3 and 3-5% slope. Cotton intercropping comprised row to row at 90 cm and plant to plant at 45 cm, while soyabean intercropping comprised 2 rows of main and 2 rows of intercrop at 45 cm. Irrespective of the slope, the highest yield of cotton was recorded under cotton + cowpea cropping system; however, the highest net return was observed under cotton + cowpea cropping system. For soyabeans, the highest yield was recorded under sole soyabean crop in both soil slopes. Among the intercropping systems, soyabean + pigeon pea had the highest yield followed by sorghum under both slopes during 2002-03. In 2003-04, soyabean + sorghum gave the highest soyabean equivalent yield in both soils followed by soyabean + pigeon pea. Comparative data on gross return, net return, average net profit and land equivalent ratio for both cotton and soyabean cropping systems are also presented.
  • Authors:
    • Liebig, M. A.
    • Merrill, S. D.
    • Krupinsky, J. M.
    • Tanaka, D. L.
    • Hanson, J. D.
  • Source: Agronomy Journal
  • Volume: 99
  • Issue: 4
  • Year: 2007
  • Summary: Producers need to know how to sequence crops to develop sustainable dynamic cropping systems that take advantage of inherent internal resources, such as crop synergism, nutrient cycling, and soil water, and capitalize on external resources, such as weather, markets, and government programs. The objective of our research was to determine influences of previous crop and crop residues (crop sequence) on relative seed and residue yield and precipitation-use efficiency (PUE) for the no-till production of buckwheat ( Fagopyrum esculentum Moench), canola ( Brassica napus L.), chickpea ( Cicer arietinum L.), corn ( Zea mays L.), dry pea ( Pisum sativum L.), grain sorghum ( Sorghum bicolor L.), lentil ( Lens culinaris Medik.), proso millet ( Panicum miliaceum L.), sunflower ( Helianthus annus L.), and spring wheat ( Triticum aestivum L.) grown in the northern Great Plains. Relative seed yield in 2003 for eight of the 10 crops resulted in synergistic effects when the previous crop was dry pea or lentil, compared with each crop grown on its own residue. Buckwheat, corn, and sunflower residues were antagonistic to chickpea relative seed yield. In 2004, highest relative seed yield for eight of the 10 crops occurred when dry pea was the previous crop. Relative residue yield followed a pattern similar to relative seed yield. The PUE overall means fluctuated for seven of the 10 crops both years, but those of dry pea, sunflower, and spring wheat remained somewhat constant, suggesting these crops may have mechanisms for consistent PUE and were not as dependent on growing season precipitation distribution as the other seven crops. Sustainable cropping systems in the northern Great Plains will approach an optimal scheme of crop sequencing by taking advantage of synergisms and avoiding antagonisms that occur among crops and previous crop residues.