• Authors:
    • Idoko, J. A.
    • Ege, O. M.
  • Source: ARPN Journal of Agricultural and Biological Science
  • Volume: 4
  • Issue: 4
  • Year: 2009
  • Summary: Field experiments were conducted at the National Root Crops Research Institute Sub-Station, Otobi in 2006 and 2007 to assess the suitability of improved Sweet potato varieties for intercropping with pigeonpea and also determine the planting pattern and productivity of this intercropping system. Intercropping decreased total fresh root and saleable root yields of sweet potato when mixed or row-intercropped with pigeonpea. All intercropping combinations of sweet potato varieties and pigeonpea had land equivalent ratio above 1.0, except that with WA Gabolige, signifying high intercrop advantages. TIS 87/0087 produced the highest total fresh root and saleable root yields in both cropping systems, irrespective of the planting pattern used. TIS 2532.O.P.1.13 and TIS 86/00356 sweet potato varieties had comparable yields with TIS 87/0087 in both cropping systems. Pigeonpea was the more competitive component of the intercropping. Farmers' willingness to adopt this technological option of sweet potato+pigeonpea intercropping further assured its potential benefits and sustainability in Southern Guinea Savanna of Nigeria.
  • Authors:
    • Joergensen, R.
    • Formowitz, B.
    • Buerkert, A.
  • Source: Plant and Soil
  • Volume: 325
  • Issue: 1/2
  • Year: 2009
  • Summary: Many microbial turnover processes in acidic sandy subtropical soils are still poorly understood. In a 59-day pot and a 189-day laboratory incubation experiment with two West African continuous cereal soils, the effects of 2 mg g -1 root residues were investigated on growth of sorghum seedlings, soil microbial biomass and activity indices, using cowpea, groundnut, pearl millet, maize and sorghum. The effects of root residues were compared with mineral P or mineral P+N treatments and with a non-fertilized control treatment. On the Alfisol (Fada, Burkina Faso), shoot dry mass was always significantly higher than on the Ultisol (Koukombo, Togo). Highest shoot dry mass was observed after application of mineral P+N on the Alfisol and after mineral P alone on the Ultisol. The application of legume root residues led to small and non-significant increases in dry mass production compared to the non-amended control, whereas the application of cereal root residues led to a decline, regardless of their origin (millet, maize or sorghum). Contents of microbial biomass C, microbial biomass N and ergosterol were 75 to 100% higher in the Alfisol than in the Ultisol, while ATP was only 36% higher. Organic amendments increased ergosterol concentrations by up to 145% compared to the control and mineral P application. Microbial biomass C and microbial biomass N increased by up to 50% after application of root residues, but ATP only up to 20%. After application of legume root residues, cumulative CO 2 production was similar in both soils with an average of 370 g CO 2-C g -1 over 189 days. After application of cereal root residues, cumulative CO 2 production was higher in the Alfisol (530 g g -1) than in the Ultisol (445 g g) over 189 days.
  • Authors:
    • Paolo, E.
    • Garofalo, P.
    • Rinaldi, M.
  • Source: Crop & Pasture Science
  • Volume: 60
  • Issue: 3
  • Year: 2009
  • Summary: The aim of this work was to apply the CropSyst simulation model to evaluate the effect of faba bean cultivation as a break crop in the continuous durum wheat cropping system in southern Italy. The model was previously calibrated and validated for durum wheat and faba bean on data derived from experiments carried out in southern Italy (for different years and treatments), comparing observed and simulated crop growth, yield, soil water, and nitrogen output variables. The validation showed good agreement between simulated and observed values for cumulative above-ground biomass, green area index, and soil water content for both crops and grain yield for durum wheat; a negative correlation for grain yield in faba bean was observed due to a reduction in harvest index in the well-watered crop, which the model does not simulate well. Subsequently, a long-term analysis was carried out to study the effects on durum wheat of introducing a legume crop in rotation with the cereal in 2 and 3-year sequences. A long-term simulation, based on 53 years of daily measured weather data, showed that faba bean, due to a lower level of transpirated water (on average 247 mm for durum wheat and 197 mm for faba bean), allowed for greater soil water availability at durum wheat sowing for the cereal when in rotation with a legume crop (on average, +84 mm/m for durum wheat following the faba bean), with positive effects for nitrogen uptake, above-ground biomass, and grain yield of wheat. The yield increase of wheat when following a faba bean crop was on average +12%, but this effect was amplified in drier years (up to 135%). In conclusion, the case study offered the potential to confirm the positive results previously obtained in long/medium-term field experiments on the introduction of faba bean in rotation with durum wheat, as well as reduction in the chemical application of nitrogen.
  • Authors:
    • Cadisch, G.
    • Giller, K.
    • Kamiri, H.
    • Gathumbi, S.
    • Ndufa, J.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 6
  • Year: 2009
  • Summary: The deliberate planting of fast-growing N 2-fixing legume monoculture species in rotation with cereal crops can be an important source of N for soil fertility replenishment. We hypothesized that mixed-species fallows have a higher potential of giving long-term residual benefits in terms of biomass, nutrients, and quality of residuals leading to long-term nutrient supply to postfallow maize ( Zea mays L.) crops. To test these hypotheses, two experiments were established in farmers' fields on very fine Kandiudalfic Eutrudox soils with monoculture and mixed-species fallows. Treatments included: sesbania [ Sesbania sesban (L.) Merr.], crotalaria ( Crotalaria grahamiana Wight and Arn.), pigeonpea [ Cajanus cajan (L.) Millsp.], siratro [ Macroptilium atropurpureum (DC.) Urb.], and calliandra ( Calliandra calothyrsus Meissn.) as monoculture-species fallow and mixture fallows of sesbania+crotalaria, sesbania+pigeonpea, sesbania+siratro, or sesbania+calliandra compared with continuous maize cropping with or without N fertilizer, and natural weed fallow. Total aboveground biomass ranged from 4.1 to 20.5 Mg ha -1 for monoculture and 7.8 to 23.3 Mg ha -1 for mixed-species fallows. Recyclable fallow biomass N ranged from 70 to 313 kg ha -1 and there was a positive interaction in some mixtures leading to increased N accumulation. Postfallow maize yields for fallows over five cropping seasons were 161-272% or 61-103% higher when compared with continuous maize without or with N fertilizer, respectively. Long-term postfallow effects on maize yield were linearly related to the amount of recycled fallow N yield. Thus, choice of fallow species to mix should be primarily driven by a better risk management strategy and an increased basket of multiple products and services.
  • Authors:
    • Celep, H.
    • Tosun, S.
    • Tiryaki, I.
    • Idikut, L.
  • Source: African Journal of Biotechnology
  • Volume: 8
  • Issue: 19
  • Year: 2009
  • Summary: A 2-year field study was conducted to evaluate effects of nitrogen (0, 12.5, 25 kg/da N) rates and previous crops on 2 hybrid corn cv Maverik and Bora varieties planted as second crop following either chickpea or wheat during 2004 and 2005. Split-split plot experimental design was used with 4 replications. Tasseling period, ear silk period, first ear height, plant height, stem diameter, ear length, 1000 seed weight, seed weight of each ear and seed yield parameters were evaluated. Results indicated that effects of previous crops for ear silk period, 1000 seed weight, seed weight of each ear and seed yield of corn varieties were highly significant during both years, while first ear height and ear length were significantly different during 2004, only. The N rates significantly affected tasseling period, ear silk period, first ear height, plant height and seed yield during both years. Effect of N rates was also significant for stem diameter and ear length during 2004 while 1000 seed weight was significant during 2005, only. There were significant differences between 2 corn varieties for tasseling period, ear silk period, first ear height, ear length, seed weight of each ear during both years whereas 1000 seed weight and seed yield showed significant differences during 2004 and stem diameter showed a significant difference during 2005, only. There was a previous crop x N rate interaction for seed yield during both years while significant previous crop x N rate interactions were determined for 1000 seed weight and seed weight of each ear in 2005. This study suggested that N rates and corn cultivars might result significant differences on tasseling period, ear silk period, first ear height, ear length and seed weight of each ear. The results also indicated that species of previous crops significantly affect corn seed yield and yield parameters and winter legumes such as chickpea might help to maximize corn yield in a crop rotation system.
  • Authors:
    • Kumar, S.
    • Thakral, S. K.
    • Kadian, V. S.
  • Source: Haryana Journal of Agronomy
  • Volume: 25
  • Issue: 1/2
  • Year: 2009
  • Summary: A field experiment was carried out from 2003-04 to 2005-06 at Agronomy Research Area of CCS Haryana Agricultural University, Hisar to find out the profitable crop rotation in south-west Haryana. In the rotation the different kharif season crops i. e. cotton ( Gossypium hirsutum L.), soybean [ Glycine max (L.) Merrill], mungbean [ Vigna radiata (L.) Wilczek], pearl millet [ Pennisetum glaucum (L.) Emend. Stuntz] and sorghum [ Sorghum bicolor (L.) Moench] were grown with rotation in rabi season crops i. e. wheat [ Triticum aestivum (L.) Emend. Fiori & Paol.], barley ( Hordeum vulgare L.), chickpea ( Cicer arietinum L.) and raya ( Brassica juncea L.). Based on the mean of three-year rotation, cotton-based rotation registered maximum land use efficiency, whereas it was lowest in sorghum-based rotations. Among the different crop rotations, cotton-barley and soybean-wheat were found profitable based on the net returns and B:C ratio. Pearl millet-based crop rotations were found remunerative as compared to other kharif season crops.
  • Authors:
    • Thelen, D.
    • Kravchenko, A.
  • Source: Journal of Sustainable Agriculture
  • Volume: 33
  • Issue: 5
  • Year: 2009
  • Summary: Wheat ( Triticum aestivum L.) crop residue can negatively affect the growth and development of no-till corn ( Zea mays L.). The objective of this study was to determine whether nitrogen management practices including legume cover crops and manure applications used in conjunction with a pre-sidedress soil nitrate test (PSNT) could be used to overcome the observed wheat residue antagonism of no-till corn growth and development. A PSNT nitrogen strategy was effective in maintaining no-till corn grain yield in wheat residue systems equivalent to no-till corn grain yield in no-wheat residue systems in 4 of 6 site years. Similar results were obtained for PSNT plus clover cover crop and PSNT plus manure plus clover cover crop nitrogen management systems. Utilization of a PSNT with manure application equalized no-till corn grain yield in high wheat residue treatments with no-till corn grain yield in treatments without wheat residue in all site years. This can be a recommended practice in the Michigan eco-region.
  • Authors:
    • Kremer, R. J.
    • Kussman, R.
  • Source: Agroforestry comes of age: putting science into practice. Proceedings of the 11th North American Agroforestry Conference, Columbia, Missouri, USA, 31 May - 3 June, 2009
  • Year: 2009
  • Summary: Intercropping alleys of agroforestry systems provides an income source until the tree crop produces harvestable yields. However, cultivation of annual crops soil organic matter and increases soil erosion, especially on sloping landscapes. Perennial crops maintain a continuous soil cover, maximize water infiltration, minimize soil erosion, and improve overall soil quality. The objective of this on-farm study was to assess the effects of a perennial legume, kura clover ( Trifolium ambiguum), on various soil quality parameters in a recently established pecan ( Carya illinoinensis) orchard. The pecan-kura clover agroforestry system was established on deep loess soils of the Missouri River hills. These silt loams are on 3 to 10% slopes and can be highly erosive. Kura clover, intercropped eight years after pecan planting, was selected based on its perennial growth habit, nitrogen-fixing ability, winter hardiness, high forage quality, and soil conservation properties. Kura clover was seeded in 2002 and harvested for hay annually beginning 2003. During this period soil organic matter and activities of selected soil enzymes have steadily increased compared with cultivated and grass pasture control soils. Water-stable aggregation improved by 50%. Results illustrate that kura clover as the interplanted component improved soil fertility and biological activity through increased organic matter and improved soil structure, and yielded high quality forage valuable for the cattle-feeding operation. Pecan trees thrive in this system partly because soil quality is maintained or improved and, unlike other "living mulch" systems in which cover crops may suppress the main crop, kura clover does not compete with tree growth.
  • Authors:
    • Jorge, R. F.
    • Cora, J. E.
    • Martins, M. dos R.
    • Marcelo, A. V.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: The adaptation of no-tillage system in tropical regions depends on the suitable choice of summer and winter crops which should contribute to improvement of soil properties. The aim of the present study was to determine the effect of crop sequences on soil aggregation and contents of organic C and polysaccharides in aggregates of a Rhodic Eutrudox under no-tillage. The treatments consisted of the combination of four summer crop sequences and seven winter crop sequences. The summer crop sequences were: maize monocrop ( Zea mays L.) (MM); soybean monocrop ( Glycine max (L.) Merrill) (SS); crop sequence of soybean/maize/soybean/maize (SM); crop sequence of rice ( Oryza sativa L.)/bean ( Phaseolus vulgaris L.)/cotton ( Gossypium hirsutum L.)/bean (RB). The winter crops were: maize, sunflower ( Helianthus annuus L.), radish ( Raphanus sativus L.), pearl millet ( Pennisetum americanum (L.) Leeke), pigeon pea ( Cajanus cajan (L.) Millsp), grain sorghum ( Sorghum bicolor (L.) Moench) and sunn hemp ( Crotalaria juncea L.). The highest total organic C, total polysaccharides and dilute acid-extracted polysaccharides contents were found in 2.00-1.00 mm water-stable aggregates and the lowest contents were found in
  • Authors:
    • Monteiro, J. E. B. A.
  • Source: Agrometeorologia dos cultivos: o fator meteorológico na produção agrícola
  • Year: 2009
  • Summary: This book brings together a broad base of information on 32 major Brazilian agricultural crops and their relations with climate. The focus of the book is not on the methodologies and applications of agrometeorology per se, but rather restricts its focus to crops and traits that determine yield as a function of the environment. The crops included are rice, castor oil, sunflowers, pineapples, soyabeans, triticale, maize, potatoes, barley, peanuts, oats, onions, canola, wheat, cotton, beans, sugarcane, Pinus, black wattle ( Acacia mearnsii), tropical and temperate grapes, coconuts, citrus, bananas, sisal, cocoa, coffee, apples, Jatropha, Eucalyptus and the fodder plants Cynodon, Brachiaria and Panicum. The contents of the book are divided into three main parts, I. Introduction, II. Temporary crops and III. Permanent crops, with each chapter within parts II and III dedicated to a particular crop, and covering: (1) the main features of farming and phenology; (2) agrometeorological productivity constraints - water availability, temperature, solar radiation, photoperiod and wind; and (3) adverse events - hail and rainstorms, droughts and dry spells, winds and gales, frost, and too much rain and over-prolonged drought. The book was organized by the National Institute of Meteorology and had the collaboration of 105 researchers from 37 Brazilian institutions (federal and state), research centres, institutes and universities.