• 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:
    • Bielders, C. L.
    • Laloy, E.
  • Source: European Journal of Soil Science
  • Volume: 60
  • Issue: 6
  • Year: 2009
  • Summary: In order to evaluate the impact of intercrop management on runoff and erosion in a continuous maize cropping system, the plot scale, continuous and process-based erosion model (CREHDYS) developed previously must be calibrated accounting for its two main outputs: runoff and sediment loss. To do that, a global Pareto multi-objective calibration was applied to these two potentially conflicting objectives, considering daily runoff and periodical erosion rates, for two sites with different slopes and soil textures. This revealed a trade-off between both objectives. The large resulting Pareto uncertainty regarding parameters did not translate into a large predictive uncertainty of daily runoff but resulted into a large uncertainty on erosion prediction. Globally, model results were satisfactory with regard to daily runoff prediction (Nash-Sutcliffe index varying within the Pareto solution set from 0.65 to 0.91 for calibration and 0.64 to 0.77 for validation period) and relatively satisfactory for periodical erosion. However, the small number of available data points (three) for model validation in terms of periodical erosion prediction was not sufficient to ensure a proper validation. The calibrated model was in turn used to perform a scenario analysis of the long-term hydrological and erosive impact of inter-cropping period management in a continuous maize cropping system, using disaggregated rainfall. The long-term simulations mainly revealed that, with regard to the erosion prevention during the inter-cropping period, planting a winter cover crop is a better option than reduced tillage with a cultivator (0-12 cm), even if the cover is destroyed early (1 January). As compared with the situation of a bare heavily crusted soil with two semi-permanent wheel tracks, reduced tillage led to an erosion reduction from 90 to 97%, an early cover destruction (1 January) to an erosion decrease from 92 to 98% and a cover destroyed on 1 March or later to an average soil loss reduction from 96 to 99%.
  • Authors:
    • Prasad, Y. E.
    • Prasad, V. R.
  • Source: Mysore Journal of Agricultural Sciences
  • Volume: 43
  • Issue: 2
  • Year: 2009
  • Summary: The present investigation is aimed at studying the relative economics of soybean based cropping systems against cotton mono crop in Gottipadu village of Prattipadu mandal in Guntur district of Andhra Pradesh. Regression analysis of soybean. Bengalgram revealed that, all the variables contributed positively but non-significant except plant protection chemicals. Regression analysis of soybean+redgram (inter crop) cropping system revealed that area and plant protection chemicals made positive and significant contribution and machine labour made negative and significant contribution towards the gross returns. Regression analysis of soybean-jowar cropping system revealed that plant protection chemicals made a significant and positive contribution whereas fertilisers made a significant and negative contribution towards gross returns. Regression analysis of cotton revealed that area, seed, manual labour and machine labour made a significant and positive contribution towards the gross returns.
  • Authors:
    • Feltran, J. C.
    • De Castro, C. M.
    • De Almeida, D. L.
    • Valle, Teresa L.
    • Duarte Ribeiro, R. De L.
    • Pries Devide, A. C.
  • Source: Bragantia
  • Volume: 68
  • Issue: 1
  • Year: 2009
  • Summary: Organic systems were evaluated for cassava root production directed to human comsumption in natura, at Seropedica-RJ. Treatments consisted of: cassava ('IAC 576-70') in single cropping and its intercropping with corn ('Eldorado'), cowpea ('Maua') or corn plus cowpea. The organic management was standardized and the experimental area was submitted to artificial irrigation during the period of stay of maize in the system. "Green" (immature) corn ears were harvested at the "point" required for fresh marketing and the shoot placed on the ground. The cowpea was included to function as green manure being Cut at flowering with residues left on the soil Surface. Corn and cowpea were sown between cassava rows, in an alternate design, following the first weeding of the main crop (cassava). The cultivar IAC 576-70 showed suitability with respect to organic management, yielding approximatelu 31 Mg ha(-1) of marketable roots. No significant differences were detected between cassava single cropping and any of the intercropping tested systems. Thus, corn crop has considerable potential for additional income to the growers. Yield of 'Eldorado' corn averaged 18.125 ears ha(-1) correspponding to 5,1 Mg ha-1. Residues coming from cowpea cutting brought about an input close to 12 Mg ha(-1), which meant an expressive contribution in nutrient elements, especially nitrogen (about 44 kg N ha(-1)). The legume crop, in addition, completely covered cassava inter-rows demonstrating its potential for controlling erosion and weeds. The triple intercropping becomes advantageous considering that corn harvesting would justify irrigation and that inclusion of cowpea meant benefitial effects to the system and did not interfere on cassava yield.
  • Authors:
    • Alsaadawi, I. S.
    • Dayan, F. E.
  • Source: Allelopathy Journal
  • Volume: 24
  • Issue: 2
  • Year: 2009
  • Summary: The promising allelopathic potential of sorghum [Sorghum bicolor L. (Moench)] opens a fruitful area of research to exploit this phenomenon in weed control and regulation of nutrients cycle. The data suggests that sorghum allelopathy can be exploited in different cropping practices [cover crop, smother crop, companion crop. mixing crop and smother crop to control weeds and inhibition of nitrification] and, application of its water extracts in fields controls the weeds and enhances the crops productivity. The herbicidal and allelopathic properties of sorgoleone. a compound isolated from root exudates of sorghum and other allelochemicals in sorghum deserve further work to identify the enzymes responsible for the biosynthesis oil these compounds and the genes encoding them. Besides there is need to use genetic engineering to manipulate the identified genes in sorghum or in other crops to enhance their ability to suppress the weeds, This review addresses the research on the role of allelopathic potential in different cropping systems and the approaches developed in weeds management.
  • Authors:
    • Jain, L.
    • Kothari, A.
    • Sharma, S.
    • Balyan, J.
    • Jat, M.
  • Source: Journal of Maharashtra Agricultural Universities
  • Volume: 33
  • Issue: 3
  • Year: 2008
  • Summary: A field experiment was conducted during the kharif season of 2001-2004 at Dryland Farming Research Station, Arjia, Bhilwara, Rajasthan, India, to study the suitability of different cropping system of maize and land treatments for reducing runoff and soil loss. Among the land treatments, flat sowing and ridging after first inter-cultural operation in maize was found more effective in reducing runoff and soil loss thereby increasing the yield of maize. Whereas, among cropping systems, intercropping of maize+black gram (2:2) was found more effective in reducing runoff and soil loss and thereby increasing crop yields as compared to sole maize and black gram.
  • Authors:
    • Owoeye, L.
    • Moriri, S.
    • Mariga, I.
  • Source: Proceedings of the 9th International Conference on Precision Agriculture, Denver, Colorado, USA
  • Year: 2008
  • Summary: Field experiments were carried out during 2005/2006 growing season at three localities to assess effects of planting density and planting patterns on crop growth, maize stover nutrient concentration and residual soil nutrient content in maize/cowpea sole and intercropped systems. The trial consisted of four maize planting densities and six planting patterns. Higher plant density of 30 000 and 40 000 maize plants ha -1 delayed flowering and maturity of both component crops in sole and intercropped systems. Maize dry matter production increased with increasing plant density up to 30 0000 plants ha -1 and reduced at higher density of 40 000 plants ha -1, whereas cowpea dry matter production decreased with increasing plant density in intercropping but this was the opposite in sole cropping. The 1rowM:2rowsC pattern and plant density of 30 000 plants ha -1 with 92 000 plants ha -1 of cowpeas was superior in maize dry matter production at all trial sites, whereas sole cowpea at 40 000 plants ha -1 gave the highest dry matter yield than the intercrop. The 2rowsM:4rowsC arrangement had the tallest cowpea plants than all other planting patterns, while the 1rowM:1rowC arrangement had the shortest at all locations throughout the sampling dates.
  • Authors:
    • Pimenov, K. I.
    • Kutuzov, G. P.
  • Source: Kormoproizvodstvo
  • Issue: 9
  • Year: 2008
  • Summary: In a 3-year experiment carried out on a common chernozem in central Russia, woad ( Isatis costata) was grown as an intercrop in fodder crop rotations. The effect of early spring cover crops (barley or an oats + peas mixture) on woad cold resistance, the optimal sowing rate (1, 2 or 3 million seeds/ha), the effect of spring nitrogen fertilizer on yield, and the productivity and effectiveness of rotations were examined. Results showed that the cover crop - woad - Sudan grass rotations gave 3 harvests within 2 years. By including woad as an undersown intercrop (at 1 million seeds/ha), the yield of the rotation involving oats + peas as cover crop increased to 12.6 thousand fodder units/ha compared to 6.5 thousand/ha in a woad-Sudan grass control.
  • Authors:
    • Pridham, J. C.
    • Entz, M. H.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 5
  • Year: 2008
  • Summary: The success of organic wheat ( Triticum aestivum L.) production can be severely inhibited by weed and disease pressures. This study sought to determine the effectiveness of wheat intercrop mixtures in suppressing weeds and diseases and increasing grain yield and net return. Field experiments were conducted on organically managed land in 2004 and 2005 and three representative intercrop systems were tested: wheat with other cereals [oats ( Avena sativa L.), barley ( Hordeum vulgare L.), and spring rye ( Secale cereale L.)]; wheat and noncereal seed crops (flax [ Linum usitatissimum L.], field pea [ Pisum sativum L.], oriental mustard [ Brassica juncea L.]); and wheat and cover crops (red clover [ Trifolium pratense L.], hairy vetch [ Vicia villosa L.], annual ryegrass [ Lolium multiflorum Lam.]). The cereal intercrop systems provided no consistent yield benefit over wheat monocultures. Results from noncereal-wheat intercrops were variable. Wheat-flax reduced the wheat crop to unacceptable levels but was capable of reducing wheat flag leaf disease levels. Wheat-field pea resulted in the lowest disease levels, yet had inconsistent yields, and more weeds than wheat monoculture. Wheat-mustard did not reduce weeds or diseases, but it was capable of high grain yields and net returns, though usually hampered by flea beetle ( Phyllotreta cruciferae) attack. The effect of cover crops on wheat was affected by environment. Wheat-red clover and wheat-hairy vetch did demonstrate the ability to maintain high wheat grain yield in certain site-years. In conclusion, wheat intercrop mixtures provided little short-term benefit over monoculture wheat in this study.
  • Authors:
    • Mechlia, N.
    • Masmoudi, M.
    • Lhomme, J.
    • Karray, J.
  • Source: Agricultural Water Management
  • Volume: 95
  • Issue: 5
  • Year: 2008
  • Summary: Water transfers within mixed crops systems are complicated to understand due to the large number of complex interactions between the various components. Standard techniques fail to provide the proper assessment of the components of the water balance. Experiments and modeling developments are used to understand the dynamics of water transfers within the association of olive trees with annual crops under irrigation in Central Tunisia. The whole system is represented by a unit area made up of three components: a plot with the annual crop, a plot with the olive tree and a plot of bare soil. The modeling approach is based on the concept of reservoir. The model works on a daily time step and accounts for the lateral transfers of water occurring between the components of the system: (i) the water uptake by the roots of olive trees; (ii) the physical flow of water between the irrigated plot and the non-irrigated ones. A field experiment was carried out during 2 years (2002, 2003) and three crop cycles (spring potato, spring pea and autumn potato) in order to calibrate the model and test its validity. Olive tree transpiration was estimated from sap flow measurements and soil moisture in the different compartments was measured by neutron probe technique. The experimental data compare fairly well with the model outputs. The first purpose of the model is to understand the functioning of the olive tree-annual crop association from a water standpoint, but it can be easily extended to other intercropping systems mixing perennial vegetation with annual crops or used as a management tool. The estimates of the water extracted by the olive trees in each reservoir appear to be much more significant than those of the water physically transferred between reservoirs.