• Authors:
    • Rao, I. M.
    • Schmidt, A.
    • van der Hoek, R.
    • Bernasconi, S. M.
    • Frossard, E.
    • Douxchamps, S.
    • Oberson, A.
  • Source: Plant and Soil
  • Volume: 341
  • Issue: 1-2
  • Year: 2011
  • Summary: The integration of multipurpose legumes into low-input tropical agricultural systems is needed because they are a nitrogen (N) input through symbiotic fixation. The drought-tolerant cover legume canavalia (Canavalia brasiliensis) has been introduced for use either as forage or as a green manure into the crop-livestock system of the Nicaraguan hillsides. To evaluate its impact on the subsequent maize crop, an in-depth study on N dynamics in the soil-plant system was conducted. Microplots were installed in a 6-year old field experiment with maize-canavalia rotation. Direct and indirect (15)N-labelling techniques were used to determine N uptake by maize from canavalia residues and canavalia-fed cows' manure compared to mineral fertilizer. Litter bags were used to determine the N release from canavalia residues. The incorporation of N from the amendment into different soil N pools (total N, mineral N, microbial biomass) was followed during the maize cropping season. Maize took up an average of 13.3 g N m(-2), within which 1.0 g N m(-2) was from canavalia residues and 2.6 g N m(-2) was from mineral fertilizer, corresponding to an amendment N recovery of 12% and 32%, respectively. Recoveries in maize would probably be higher at a site with lower soil available N content. Most of the amendment N remained in the soil. Mineral N and microbial N were composed mainly of N derived from the soil. Combined total (15)N recovery in maize and soil at harvest was highest for the canavalia residue treatment with 98% recovery, followed by the mineral fertilizer treatment with 83% recovery. Despite similar initial enrichment of soil microbial and mineral N pools, the indirect labelling technique failed to assess the N fertilizer value of mineral and organic amendments due to a high N mineralization from the soil organic matter.
  • Authors:
    • Wokocha, C. C.
    • Eludoyin, O. S.
  • Source: Asian Journal of Agricultural Sciences
  • Volume: 3
  • Issue: 2
  • Year: 2011
  • Summary: The present study evaluated the impacts of maize cultivation on soil properties under the continuous monocropping system of farming in South-western Nigeria. Soil samples were collected from both cultivated maize plot and less disturbed secondary forest, both lying contiguous to each other. Laboratory analysis was carried out to determine the levels of particle size composition, porosity, bulk density; and concentrations of Cations Exchange Capacity (CEC), Exchangeable Sodium (Na), Exchangeable Calcium (Ca), Exchangeable Magnesium (Mg), Available Phosphorous (P), Soil pH, Exchangeable Acidity, Organic Carbon (C) and Nitrogen (N). The mean of each of these soil properties was used for comparison and t-test was also used to determine the significant difference that exists in each soil property. The result shows that the level of C, N and porosity were higher in soils under forest than soils under maize. However, there was no significant difference in Exchangeable Acidity, Mg, Soil pH and Ca in the two land use types. Nevertheless, the concentrations of Na and K were higher in the cultivated soils while P and Ca were lower in the cultivated soils. The particle size composition was predominantly sandy. Planting of cover crops, mixed cropping and mulching among others were suggested as ways to minimize erosion and leaching so that fertility can be restored and maintained.
  • Authors:
    • Muthukrishnan, P.
    • Fanish, S. A.
  • Source: Madras Agricultural Journal
  • Volume: 98
  • Issue: 10/12
  • Year: 2011
  • Summary: Field experiments were conducted at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, during kharif 2008 and 2009 to study the effect of different fertigation levels and intercrops in intensive maize based intercropping system. The experiment was laid out in strip plot design with three replications. The experiment comprised of nine fertigation levels in main plot, viz M 1, Surface irrigation with soil application of 100% RDF; M 2, Drip irrigation with soil application of 100% RDF; M 3, Drip fertigation of 75% RDF; M 4, Drip fertigation of 100% RDF; M 5, Drip fertigation of 125% RDF; M 6, Drip fertigation of 150% RDF; M 7, Drip fertigation of 50% RDF (50% P and K as Water Soluble Fertilizer (WSF)); M8, Drip fertigation of 75% RDF (50% P and K as WSF); M 9, Drip fertigation of 100% RDF (50% P and K as WSF) and four intercrops in sub plot viz, S 1, Vegetable coriander; S 2, Radish; S 3, Beet root; S 4, Onion. Drip fertigation at 100 per cent RDF with 50 per cent P and K as WSF in maize+radish intercropping system recorded a higher gross income of Rs. 83438/ha whereas, higher net return and benefit cost ratio of Rs. 56858 and 3.24, respectively, were recorded by drip fertigation at 150 per cent RDF with radish as intercrop system.
  • Authors:
    • Manoharan, S.
    • Muthukrishnan, P.
    • Fanish, S. A.
  • Source: Indian Journal of Agricultural Research
  • Volume: 45
  • Issue: 3
  • Year: 2011
  • Summary: Field experiments were conducted during kharif 2008-2009 at Tamil Nadu agricultural University, Coimbatore to study the effect of drip fertigation on growth, yield and economics of intensive maize based intercropping system. Drip fertigated maize with 100 per cent recommended dose of fertilizer (RDF) with 50 per cent P and K as water soluble fertilizer recorded significantly higher grain yield followed by 150 per cent RDF. Among the different intercropping systems, radish intercropped with maize registered higher maize grain equivalent yield of 11153 kg ha -1. Drip irrigation saved water upto 43 per cent, besides enhancing the water use efficiency. Higher net returns (Rs. 56858) and B:C ratio (3.24) were obtained under dripfertigation with 150 per cent recommended dose of fertilizer and radish as intercrop.
  • Authors:
    • Muthukrishnan, P.
    • Fanish, S. A.
    • Sekar, S. P.
  • Source: Crop Research (Hisar)
  • Volume: 42
  • Issue: 1/2/3
  • Year: 2011
  • Summary: Field experiments were conducted during kharif 2008 and 2009 at Tamil Nadu Agricultural University, Coimbatore to study the effect of drip fertigation on growth, yield and economics in intensive maize based intercropping system. During kharif 2008, drip fertigated maize at 150% RDF recorded significantly higher grain yield of 7338 kg/ha. Whereas during kharif 2009, higher grain yield of 7464 kg/ha was recorded under drip fertigation of 100% RDF with 50% P and K as water soluble fertilizer (WSF). Among the different intercropping systems, radish intercropped with maize registered a higher maize grain equivalent yield (MEY) of 11153 kg/ha. Drip irrigation helped to save the water upto 43% compared to surface irrigation besides enhancing the water use efficiency. A higher net return (Rs. 56858) and B:C ratio (3.24) were obtained under drip fertigation of 150% RDF+radish as intercrop combination.
  • Authors:
    • Groot, J. C. J.
    • Lantinga, E. A.
    • Navarro-Garza, H.
    • Koerkamp-Rabelista, J. Kleine
    • Flores-Sanchez, D.
    • Kropff, M. J.
    • Rossing, W. A. H.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 91
  • Issue: 2
  • Year: 2011
  • Summary: Enhanced utilization of ecological processes for food and feed production as part of the notion of ecological intensification starts from location-specific knowledge of production constraints. A diagnostic systems approach which combined social-economic and production ecological methods at farm and field level was developed and applied to diagnose extent and causes of the perceived low productivity of maize-based smallholder systems in two communities of the Costa Chica in South West Mexico. Social-economic and production ecological surveys were applied and complemented with model-based calculations. The results demonstrated that current nutrient management of crops has promoted nutrition imbalances, resulting in K-and, less surprisingly N-limited production conditions, reflected in low yields of the major crops maize and roselle and low resource use efficiencies. Production on moderate to steep slopes was estimated to result in considerable losses of soil and organic matter. Poor crop production, lack of specific animal fodder production systems and strong dependence on animal grazing within communal areas limited recycling of nutrients through manure. In combination with low prices for the roselle cash crop, farmers are caught in a vicious cycle of cash shortage and resource decline. The production ecological findings complemented farmers opinions by providing more insight in background and extent of livelihood constraints. Changing fertilizer subsidies and rethinking animal fodder production as well as use of communal lands requires targeting both formal and informal governance structures. The methodology has broader applicability in smallholder systems in view of its low demand on capital intensive resources.
  • Authors:
    • Bueno, O. de C.
    • Frigo, E. P.
    • Frigo, M. S.
    • Esperancini, M. S. T.
    • Klar, A. E.
  • Source: Energia na Agricultura
  • Volume: 26
  • Issue: 2
  • Year: 2011
  • Summary: The knowledge production and energy expenditure in agriculture is crucial due to strategic importance which occupies as a producer of energy inputs to other economic sectors, such as biodiesel produced from oilseed crops, so this study was attempt to determine the energy cost of partial deployment and conduct of corn intercropping agroecosystem with physic nut, under the steering and without irrigation, in an experiment conducted in accordance with the productive system of family farming in the west of Parana State. Such a study is justified due to the scarcity of energy data of the culture of physic nut under brazilian conditions, as well as in intercropping system under technological conditions of the family farm west of Parana, and especially environmental issues involved in this study as the rational use of energy sources nonrenewable. The experiment was conducted in accordance with the techniques employed by family farmers in western Parana, from February 2008 to May 2008 for corn and from February 2008 to November 2009 for the cultivation of physic nut in the Experimental Center of Agricultural Engineering (NEEA), belonging to the State University of Western Parana (UNIOESTE), campus of Cascavel/PR, in the area of tillage. The final product was assessed only corn. The technical coefficients, the workload, performance, identification of the tractor, implements and equipment, their specifications and their consumption of fuel, lubricants and greases, as well as quantification of manpower used were derived from primary data and secondary. The methodology consisted of determining the "Efficiency Cultural Partial" and "Energy Efficiency Partial". Regarding the energy balance in part, cultural and energy efficiency partial there were no major differences between the systems studied. We conclude that the conditions of the experiment the conduction system assessed in terms of energy both systems have the same performance.
  • Authors:
    • Gabriel, J. L.
    • Quemada, M.
  • Source: European Journal of Agronomy
  • Volume: 34
  • Issue: 3
  • Year: 2011
  • Summary: Cover crops in dry regions have been often limited by low nutrient and water-use efficiency. This study was conducted during 3.5 years to determine the effect of replacing bare fallow by a cover crop on yield, N uptake, and fate of labeled fertiliser in an intensive maize production system. Three treatments were studied: barley ( Hordeum vulgare L.), vetch ( Vicia villosa L.) and bare fallow during the intercropping period of maize ( Zea mays L.). All treatments were irrigated and fertilised following the same procedure, and a microplot in each plot was established with 210 kg N ha -1 of double labeled ammonium nitrate. Crop yield and N uptake, soil mineral N (N min), and recovery of 15N in plant and soil were determined after maize harvest and killing the cover crop. Replacing bare fallow with cover crops did not affect subsequent maize yield but affected N uptake. Vetch increased N supply by legume residues after the second year, and the N content in grain by the third. Nitrogen recover from fertiliser was not affected by treatment and averaged 46%. Barley recovered more 15N during the autumn-winter period than vetch or fallow. Under representative conditions, average barley N content was 47, vetch 51, and spontaneous vegetation content 0.8 kg N ha -1. Recovery of 15N in barley comprised 19% of total N content in aerial biomass, while only 4% in vetch. Vetch enhanced soil 15N recovery more than other treatments, suggesting its presence in a fairly stable organic fraction unavailable for maize uptake or lost. Replacing bare fallow by a cover crop only reduced fertiliser losses in a year with abundant precipitation. Nevertheless, reduction in soil N min in vetch and bare fallow treatments was similar, showing that N losses can be reduced in this cropping system, either by replace bare fallow with barley or smaller N fertiliser application to maize.
  • Authors:
    • Dadhwal, K. S.
    • Sharma, N. K.
    • Ghosh, B. N.
  • Source: Indian Journal of Soil Conservation
  • Volume: 39
  • Issue: 3
  • Year: 2011
  • Summary: Agricultural land use coupled with cropping system and integrated nutrient management (INM) can enhance crop yields, water productivity, improve soil health and income to the farmers. To test this hypothesis, four technologies namely rainfed; (i) maize+cowpea (1:2)-wheat, (ii) maizewheat+mustard (9:1), (iii) irrigated, paddy-wheat, paddy (System of rice intensification, SRI) - wheat and (iv) maize-potato-onion with INM to each crop rotations were experimented and demonstrated on farmer's fields in the agroclimatic zone of valley land of north-west Himalayas (Agro-ecological 14) in the districts of Dehradun (Uftarakhand) and Sirmour (Himachal pradesh) during 2007-09. Two years pooled data indicated that maize-potato-onion rotation rendered highest maize equivalent yield (18762 kg ha -1) among all the cropping system, followed by paddy wheat (10789 kg ha -1) and maize-wheat+mustard intercropping system (4826 kg ha -1). Of the two rainfed systems, maize-wheat+mustard gave slightly higher (1.5%) maize equivalent yield than maize- + cowpea-wheat sequence whereas under limited irrigation condition, maize-potato-onion exhibited significantly higher (73.9%) maize equivalent yield than paddy-wheat system. Results also revealed that on an average, yield, water use efficiency (WUE) and net return increased to the tune of 40.7, 44.7 and 89.9%, respectively on adoption of technology in the farmer's field over conventional farming irrespective of crop rotations. Water use in system of rice intensification (SRI) with INM technology was 80-90 mm less than fanners practice. On adoption of INM technology, the soil quality index (SQI) improved from 11.9 to 18.8% exhibiting highest in maize-potato-onion and lowest in paddy-wheat system. It is inferred that maize-potato-onion under limited irrigation treatment and maize-wheat+mustard under rainfed conditions are the best management options for maximizing water productivity, net return and soil quality.
  • Authors:
    • Huffman, R. L.
    • Grabow, G. L.
    • Evans, R. O.
  • Source: Journal of Irrigation and Drainage Engineering
  • Volume: 137
  • Issue: 1
  • Year: 2011
  • Summary: A subsurface drip irrigation (SDI) system was installed in the Piedmont of North Carolina in a clay soil in the fall of 2001 to test the effect of dripline spacing on corn and soybean yield. The system was zoned into three sections; each section was cropped to either corn ( Zea mays L.), full-season soybean [ Glycine max (L.) Merr.], or winter wheat ( Triticum aestivum) double cropped to soybean representing any year of a typical crop rotation in the region. Each section had four plots; two SDI plots with dripline spacing at either 1.52 or 2.28 m, an overhead sprinkler irrigated plot, and an unirrigated plot. There was no difference in average corn grain yield for 2002-2005 between dripline spacings or between either dripline spacing and sprinkler. Irrigation water use efficiency (IWUE) was greater for sprinkler irrigated corn than for either SDI treatment and there was no difference in IWUE in soybean. Water typically moved laterally from the driplines 0.38 to 0.50 m. SDI yield and IWUE increased relative to sprinkler yields and water use efficiency in the second and third year of the study. This may suggest that initial fracturing of the heavy clay soil during SDI system installation and subsequent settling of the soil affected water distribution.