• 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:
    • 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:
    • Kumar, V.
    • Kumar, V.
    • Saharawat, Y. S.
    • Ladha, J. K.
    • Gathala, M. K.
    • Sharma, P. K.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 5
  • Year: 2011
  • Summary: Rice-wheat (Oryza sativa L.-Triticum aestivum L.) rotation is the major production system in Asia, covering about 18 million ha. Conventional practice of growing rice (puddled transplanting) and wheat (conventional till, CT) deteriorate soil physical properties, and are input- and energy-intensive. Zero-tillage (ZT) along with drill-seeding have been promoted to overcome these problems. A 7-yr permanent plot study evaluated various tillage and crop establishment (CE) methods on soil physical properties with an aim to improve soil health and resource-use efficiency. Treatments included transplanting and direct-seeding of rice on flat and raised beds with or without tillage followed by wheat in CT and ZT soil. Bulk density (D(b)) of the 10- to 20-cm soil layer was highest under puddled treatments (1.74-1.77 Mg m(-3)) and lowest under ZT treatments (1.66-1.71 Mg m(-3)). Likewise, soil penetration resistance (SPR) was highest at the 20-cm depth in puddled treatments (3.46-3.72 MPa) and lowest in ZT treatments (2.51-2.82 MPa). Compared with conventional practice, on average, water-stable aggregates (WSAs) > 0.25 mm were 28% higher in ZT direct-seeding with positive time trend of 4.02% yr(-1). Infiltration was higher (0.29-0.40 cm h(-1)) in ZT treatments than puddled treatments (0.18 cm h(-1)). The least-limiting water range was about double in ZT direct-seeding than that of conventional practice. Gradual improvement in soil physical parameters in ZT system resulted in improvement in wheat yield and is expected to be superior in long-run on system (rice+wheat) basis. Further research is needed to understand mechanisms and requirements of two cereals with contrasting edaphic requirements in their new environment of ZT direct-seeding.
  • Authors:
    • Nagih, A.
    • Lemalade, J. L.
    • Alfandari, L.
    • Plateau, G.
  • Source: Annals of Operations Research
  • Volume: 190
  • Issue: 1
  • Year: 2011
  • Summary: We propose a Mixed-Integer Linear Programming model for a class of multi-period crop rotation optimization problems with demand constraints and incompatibility constraints between cultivation and fallow state on a land plot. This model is applied to a case study on Madagascan farms in the scope of a sustainable development campain against deforestation, where the objective is to better control agricultural space while covering seasonal needs of farmer. We propose an efficient upper bound computation and study the variation of the minimum number of plots and total space needed in function of the unitary surface area of a plot. Numerical results associated with the Madagascan case are reported.
  • Authors:
    • Peluzio, J. M.
    • Almeida, R. D. de
    • Afférri, F. S.
  • Source: Revista Ciência Agronômica
  • Volume: 42
  • Issue: 1
  • Year: 2011
  • Summary: The aim of this work was to evaluate the genetic divergence among twelve soybean cultivars under irrigated lowland conditions in south Tocantins State, Brazil, in the Companhia Brasileira de Agropecuaria (COBRAPE), at Formoso do Araguaia, TO, in the inter-cropping 2005. The experimental design employed was randomized blocks with twelve treatments and tree replications. The treatments consisted on the following cultivars: DM Vitoria, MG/BR 46 (Conquista), Suprema, BRS Pintado, DM 247, BRS/MG 68, BRS/MG Lideranca, BRS MG Seguranca, DM 339, BRS/MG Garantia, A 7002, and DM 309. The following characteristics were evaluated: grain yield, weight of hundred seeds, number of seeds per pod, number of pods per plant, number of days for flowering; number of days for maturation, plant height and height insertion of the primary pod. Genetic divergence was evaluated by multivariate procedures: generalized Mahalanobis distance, Tocher's agglomerative method of Tocher and nearest neighbor. The Tocher's method and nearest neighbor agreed among themselves. Number of days for the maturation (39.49%), weigh of hundred seeds (26.56%) and number of days for flowering (13.59%) were the traits that most contributed to the genetic dissimilarity. The presence of genetic variability allowed the identification of dissimilar cultivars with high average for the traits studied. BRS/MG Garantia * DM 339 and BRS/MG Garantia * MG/BR 46 (Conquista) hybridizations are promising for obtaining segregate populations with higher variability.
  • Authors:
    • Gautam, M.
    • Ambati, R. R.
    • Reddy, A. R.
  • Source: Indian Journal of Agronomy
  • Volume: 56
  • Issue: 4
  • Year: 2011
  • Summary: Field trials were conducted to validate farm pond sizes for supplemental irrigations during 2004-2011 at the Central Institute for Cotton Research, Nagpur (′21degrees09′N, 79degrees09′E.). Ten farm ponds 200 to 15,120 m 3 size resulted in a runoff storage of about 60, 75 and 28, 36, 58% (2007, 2010 and 2008, 2009, 2011) in normal and drought years at the end of August month. During actual drought the water availability was 0 and 18% only of the capacity designed in 2011 and 2008 July seedling droughts. Special recharging techniques like opening borewells/percolation tanks etc in under ground storages and using it with sprinkler irrigation during seedling droughts is the only option. Two supplemental irrigations at flowering stage along with application of deficient micronutrients on shallow and medium soils to Bt hybrid cotton ( G. hirsutum L.) resulted in increased seed cotton yield by 50% and 44%, which was verified during 2008 and 2009 seasons in Yeotmal district. The minimum economical catchment was found to be 21 ha or 0.7 ha m pond size, with which 25% and 50% area could be irrigated by conventional and alternate furrow/sprinkler irrigation respectively, with a payback period (PBP) of 2 years in Bt hybrid cotton. Rotational soybean ( Glycine max (L.) Merrill) could be irrigated to the extent of 16 and 33% catchment area with improved water use efficiency (WUE) from 250 to 500 kg/ha-cm for 1.5 and 3.5 years of pay back period (PBP) under conventional and sprinkler irrigation, respectively, during drought conditions. The same sprinkler and drip irrigation systems could also be used to irrigate subsequent wheat [ Triticum aestivum (L.) emend. Fiori & Paol] crop with a gravitational well, covering 14 and 57% of catchment area with WUE of 180 kg/ha-cm with a PBP of 11 and 21 years.
  • Authors:
    • Yawson, D. O.
    • Obiri, S.
    • Yengoh, G. T.
    • Odoi, J. O.
    • Armah, F. A.
    • Afrifa, E. K. A.
  • Source: Mitigation and Adaptation Strategies for Global Change
  • Volume: 16
  • Issue: 3
  • Year: 2011
  • Summary: Desertification, climate variability and food security are closely linked through drought, land cover changes, and climate and biological feedbacks. In Ghana, only few studies have documented these linkages. To establish this link the study provides historical and predicted climatic changes for two drought sensitive agro-ecological zones in Ghana and further determines how these changes have influenced crop production within the two zones. This objective was attained via Markov chain and Fuzzy modelling. Results from the Markov chain model point to the fact that the Guinea savanna agro-ecological zone has experienced delayed rains from 1960 to 2008 while the Sudan savanna agro-ecological zone had slightly earlier rains for the same period. Results of Fuzzy Modelling indicate that very suitable and moderately suitable croplands for millet and sorghum production are evenly distributed within the two agro-ecological zones. For Ghana to adapt to climate change and thereby achieve food security, it is important to pursue strategies such as expansion of irrigated agricultural areas, improvement of crop water productivity in rain-fed agriculture, crop improvement and specialisation, and improvement in indigenous technology. It is also important to encourage farmers in the Sudan and Guinea Savanna zones to focus on the production of cereals and legumes (e.g. sorghum, millet and soybeans) as the edaphic and climatic factors favour these crops and will give the farmers a competitive advantage. It may be necessary to consider the development of the study area as the main production and supply source of selected cereals and legumes for the entire country in order to free lands in other regions for the production of crops highly suitable for those regions on the basis of their edaphic and climatic conditions.
  • Authors:
    • Risede, J.-M.
    • Foster, J.
    • Rhodes, R.
    • Berry, S. D.
    • van Antwerpen, R.
  • Source: International Journal of Pest Management
  • Volume: 57
  • Issue: 4
  • Year: 2011
  • Summary: Plant-parasitic nematodes cause significant yield losses to sugarcane crops in South Africa. The currently available chemicals for nematode control are both expensive and potentially detrimental to the environment. Various alternative crops have been reported to reduce the numbers of plant-parasitic nematodes. Mindful of this, we evaluated 27 cover crops in pot trials to assess their host status to important plant-parasitic nematodes of sugarcane. All of the crops tested in pots hosted significantly lower numbers of Pratylenchus than did sugarcane. Crops such as cowpeas, tomato and grazing vetch were good hosts for Meloidogyne and would not be good choices as part of a sugarcane rotation system in heavily-infested soils. Conversely, crops such as oats, wheat, forage peanuts and marigolds reduced numbers of Meloidogyne. Velvet beans increased the abundance of Helicotylenchus, a beneficial nematode genus. A field trial was also conducted to study the effect of different cover cropping sequences. Our results show that changes in nematode communities occurred within three months of growing these crops and often remained low for the duration (the remaining 15 months) of the crops' growth. Nematodes such as Pratylenchus and Tylenchorhynchus were significantly lowered and remained so for the duration of the trial.