• Authors:
    • Albuquerque, J. A.
    • Reichert, J. M.
    • Reinert, D. J.
    • Genro Junior, S. A.
  • Source: CIENCIA RURAL
  • Volume: 39
  • Issue: 1
  • Year: 2009
  • Summary: A study was conducted to evaluate the effects of crop succession and rotation on the crop yields and physical properties of an oxisol (clayey Haplortox) under no-tillage system, in Rio Grande do Sul State, Brazil. The treatments included four cropping sequences, used from 1998 to 2001: (1) succession wheat/soyabean; (2) rotation corn/oat/corn + Cajanus cajan/wheat/soyabean/wheat; (3) rotation Cajanus cajan/wheat/soyabean/wheat/soybean/oat; and (4) rotation Crotalaria juncea/wheat/soyabean/oat/corn/wheat. In October 2000 and 2001, soil samples were collected to determine the physical properties, and in all years, crop yields were measured. The oxisol under no-tillage had a high degree of compaction with the greater soil bulk density and lower macroporosity than the critical limit for clay texture. The largest limitations were observed below the layer of 0-0.03 m, because in the uppermost layer, soil mobilization by successive operations of fertilizer application and sowing increased soil porosity and reduced soil density. Thus, greater volume of pores was observed between soil saturation and field capacity, responsible for soil aeration, and between field capacity and wilting point, responsible for storage of plant available water. The use of cover crops once every three years was not efficient to reduce soil compaction. The yield of the subsequent crops was positively influenced in the rotation with Crotalaria juncea, while the other cropping systems did not differ from crop succession.
  • Authors:
    • Zheng, M.
    • Wang, T.
    • Li, Z.
    • Cai, C.
    • Guo, Z.
  • Source: Agroforestry Systems
  • Volume: 76
  • Issue: 1
  • Year: 2009
  • Summary: Land management practices that simultaneously improve soil properties are crucial to high crop production and minimize detrimental impact on the environment. The effects of crop residues on crop performance, the fluxes of soil N 2O and CO 2 under wheat-maize (WM) and/or faba bean-maize (FM) rotations in Amorpha fruticosa (A) and Vetiveria zizanioides (V) intercropping systems on a loamy clay soil, in subtropical China, were examined. Crop performance, soil N 2O and CO 2 as well as some potential factors such as soil water content, soil carbon, soil nitrogen, microbial biomass and N mineralization were recorded during 2006 maize crop cultivation. Soil N 2O and CO 2 fluxes are determined using a closed-based chamber. Maize yield was greater after faba bean than after wheat may be due to differences in supply of N from residues. The presence of hedgerow significantly improved maize grain yields. N 2O emissions from soils with maize were considerably greater after faba bean (345 g N 2O-N ha -1) than after wheat (289 g N 2O-N ha -1). However, the cumulated N 2O emissions did not differ significantly between WM and FM. The difference in N 2O emissions between WM and FM was mostly due to the amounts of crop residues. Hedgerow alley cropping tended to emit more N 2O than WM and FM, in particular A. fruticosa intercropping systems. Over the entire 118 days of measurement, the N 2O fluxes represented 534 g N 2O-N ha -1 (AWM) and 512 g N 2O-N ha -1 (AFM) under A. fruticosa species, 403 g N 2O-N ha -1 (VWM) and 423 g N 2O-N ha -1 (VFM) under Vetiver grass. A significantly higher CO 2 emission was observed in AFM (5335 kg CO 2-C ha -1) from June to October, whereas no significant difference was observed among WM (3480 kg CO 2-C ha -1), FM (3302 kg CO 2-C ha -1), AWM (3877 kg CO 2-C ha -1), VWM (3124 kg CO 2-C ha -1) and VFM (3309 kg CO 2-C ha -1), indicating the importance of A. fruticosa along with faba bean residue on CO 2 fluxes. As a result, crop residues and land conversion from agricultural to agroforestry can, in turn, influence microbial biomass, N mineralization, soil C and N content, which can further alter the magnitude of crop growth, soil N 2O and CO 2 emissions in the present environmental conditions.
  • Authors:
    • Ngouajio, M.
    • Kaya, E.
    • Isik, D.
    • Mennan, H.
  • Source: Crop Protection
  • Volume: 28
  • Issue: 4
  • Year: 2009
  • Summary: Weed control is a major constraint for organic production around the world. Field studies were conducted in pepper ( Capsicum annuum L.) from 2004 to 2006 at the Black Sea Agricultural Research Institute experimental field in Turkey to determine the weed suppressive effects of winter cover crops. Treatments consisted of ryegrass ( Lolium multiflorum L.), oat ( Avena sativa L.), rye ( Secale cereale L.), wheat ( Triticum aestivum L.), gelemen clover ( Trifolium meneghinianum Clem.), Egyptian clover ( Trifolium alexsandrinum L.), common vetch ( Vicia sativa L.), hairy vetch ( Vicia villosa Roth.) and a bare fallow with no cover crop. Weed density and total weed dry biomass were assessed at 14, 28, and 56 days after incorporation to quantify effects of cover crops during a subsequent pepper crop. Cover crop establishment was similar in both growing seasons and individual species produced in the range of 1800-3500 kg/ha biomass. Ryegrass produced the greatest biomass compared with other species. Weed dry biomass production just before cover crop incorporation varied with year and cover crop species. Hairy vetch, ryegrass, oat and common vetch were the most competitive cover crops based on total weed dry biomass. Hairy vetch was the most promising cover crop and reduced weed density by 73% and 70% at 28 and 56 DAI, respectively. Pepper yields were higher following all cover crops except Egyptian clover. The highest yield was obtained from hairy vetch plots in both years. This research indicates that cover crops such as hairy vetch, ryegrass, oat and common vetch could be used in integrated weed management programs to reduce weed infestation in organic pepper.
  • Authors:
    • Nagaki, M.
    • Ke, F.
  • Source: Agricultural Information Research
  • Volume: 18
  • Issue: 2
  • Year: 2009
  • Summary: In the arid areas of Northwest China, agriculture especially crop farming consumes most of water resource. Water-intensive and low value-added wheat is cultivated as a staple food of the local people in large scale. Because of the surface water scarcity, irrigation mainly depends on pumping the groundwater in these areas. Based on field surveys conducted in 2005 and 2006 both in the south and the north of Minqin County, Gansu province, this study is designed to study the role of groundwater irrigation on wheat production and how to improve the technical efficiencies (TEs) of wheat farmers by estimating a Stochastic Frontier Production Function (SFPF). The above information is valuable for how to save wheat water consumption and improving the food safety in the arid areas. The empirical results showed that expenditure on pumping groundwater played important role in wheat production. Meanwhile, the same expenditure played more effectively on wheat intercropping with maize in the south than that in the north. As a result, the farmers in the south are more likely to increase expenditures on pumping water than the farmers in the north. Therefore, the government should make new program to restrict wheat water consumption and to secure the farmers in both areas to use the groundwater fairly. Meanwhile, it is suggested that younger farmers can achieve a higher TE both in the south and the north. For the input-intensive intercropping in the south, a larger family, higher education of the farm managers, and coordination of their part-time jobs with agricultural production activities can also help to get higher TEs.
  • Authors:
    • Wang, X.
    • Yang, Y.
    • Wu, F.
    • Li, Q.
  • Source: Acta Agriculturae Scandinavica Section B-Soil and Plant Science
  • Volume: 59
  • Issue: 5
  • Year: 2009
  • Summary: We studied the effects of rotation and interplanting on soil bacterial communities and crop yields using cucumber as the main vegetable. Onion and garlic were used as interplanting species, and wheat, soybean, villose (more commonly, villous) vetch, clover, and alfalfa were used as rotation plants. T-RFLP techniques were used to show the effects of rotation and interplanting systems on diversity index and richness index of cucumber rhizosphere soil bacterial communities. The results showed that both rotation and interplanting systems increased the richness index and diversity index of soil bacterial community structures, except where alfalfa was used as the rotation plant. The diversity index of the cucumber rhizosphere bacterial community structure was highest in the wheat rotation cropping system, and the richness index of soil bacteria was highest in wheat and clover rotations and in the onion interplanting system. Our results show that rotation and interplanting systems beneficially altered community structures of dominant soil bacteria, and increased cucumber yield and soil bacterial diversity. The best cultivation system to increase cucumber yield utilized onion as an interplanting species and wheat as a rotation plant.
  • Authors:
    • Logsdon, G.
  • Source: Small-scale grain raising
  • Issue: Ed.2
  • Year: 2009
  • Summary: This book (12 chapters) discusses the basics of the organic farming and processing of whole grains (specifically maize, wheat, sorghum, oats, dry beans, rye and barley, buckwheat and millet, rice, some uncommon grains, and legumes) for home gardeners and small-scale farmers. Topics covered include planting; pest, weed and disease management; harvesting; and processing, storing and using whole grains. Some recipes are also included.
  • Authors:
    • Isk, D.
    • Ngouajio, M.
    • Mennan, H.
    • Kaya, E.
  • Source: PHYTOPARASITICA
  • Volume: 37
  • Issue: 4
  • Year: 2009
  • Summary: Weed control is a major concern for organic farmers around the world and non-chemical weed control methods are now the subject of many investigations. Field studies were conducted in tomato ( Solanum lycopersicum L.) from 2004 to 2006 at the Black Sea Agricultural Research Institute experiment field to determine the weed suppressive effects of winter cover crops. Treatments consisted of ryegrass ( Lolium multiflorum L.), oat ( Avena sativa L.), rye ( Secale cereale L.), wheat ( Triticum aestivum L.), gelemen clover ( Trifolium meneghinianum Clem.), Egyptian clover ( Trifolium alexandrinum L.), common vetch ( Vicia sativa L.), hairy vetch ( Vicia villosa Roth.) and a control with no cover crop. Treatments were arranged in a randomized complete block design with four replications. To determine the weed suppressive effects of the cover crops, weed density and total weed dry biomass were assessed at 14, 28, and 56 days after termination (DAT) of the cover crops from all plots using a 50*50 cm quadrat placed randomly in each plot. After cover crop kill and incorporation into soil, tomato seedlings variety 'H2274' were transplanted. Broadleaved weed species were the most prominent species in both years. Total weed biomass measured just prior to cover crop incorporation into the soil was significantly lower in S. cereale plots than in the others. The number of weed species was lowest at 14 DAT and later increased at 28 and 56 DAT, and subsequently remained constant during harvest. This research indicates that cover crops such as L. multiflorum, S. cereale, V. sativa and V. villosa could be used in integrated weed management programs to manage some weeds in the early growth stages of organic tomato.
  • Authors:
    • Ben-Hammouda, M.
    • Errouissi, F.
    • Moussa-Machraoui, S.
    • Nouira, S.
  • Source: Soil & Tillage Research
  • Volume: 106
  • Issue: 2
  • Year: 2009
  • Summary: No-tillage (NT) is becoming increasingly attractive to farmers worldwide because it clearly reduces production costs relative to conventional tillage (CT) and improves soil properties and crop yield. Currently, under semi-arid conditions in North Africa, modern no-tillage techniques are being practiced on several hectares of land. The effect of NT and CT management and crop rotation on soil properties under semi-arid Mediterranean conditions was studied, over a 4-year period at two locations in northern Tunisia. Data from a short-term (2000-2004) use of both no-tillage (NT) and conventional tillage (CT) at the ESAK (Tunisia) were used to evaluate the influence of the tillage systems on the physicochemical properties of soil at the 0-20 cm depth layers. Trial was set up in 2000, where the two tillage systems (CT and NT), and four crop types (durum wheat, barley, pea and oats) were implemented in two distinct sites close to two governorates: Kef (silt/clayey) and Siliana (sand/clay) in northwestern Tunisia. Four years after implementing the two different tillage systems, soil parameters (N, NO 32-, NH 4+ P, P 2O 5, K, K 2O, SOC, SOM and CEC) were determined and comparison between the two tillage systems was made. Our results showed that after 4 years the contents of some parameters for most crop types were greater under NT than under CT at 0-20 cm depth layers, the results varied depending on crop type and site. NT significantly improved soil content especially for K, K 2O, P 2O 5 and N. Under NT system SOM and SOC were enhanced, but without significant results. These enhancements were accompanied by the enhancement of the CEC and the decrease of the C/N ratio. Thus the mineralization process was slightly quicker under NT. Our results also indicate that residue cover combined with no-tillage appears to improve some agronomic parameters and biomass production (grain yield). Multivariate analyses indicate that the improvement of soil properties was dependant on tillage management, sites (climate and soil type) and crop succession (species and cover residue). It must be pointed out that a 4-year period was not sufficient to clearly establish some parameters used in the effects of the NT system on soil properties under semi-arid conditions in northwestern Tunisia.
  • Authors:
    • Manoj, K.
    • Suresh, K.
    • Yadav, S.
    • Pawan, K.
  • Source: Haryana Journal of Agronomy
  • Volume: 25
  • Issue: 1/2
  • Year: 2009
  • Summary: A field experiment was conducted for four consecutive years from 2002-03 to 2005-06 in pearl millet-wheat cropping system under semi-arid conditions at research farm of CCS Haryana Agricultural University, Hisar, India. The experiment consisted of four treatments viz., T 1: Recommended package for both the crops, T 2: Recommended package for both crops+FYM 10 t/ha to pearl millet, T 3: Recommended package for bothcrops+FYM 10 t/ha to pearl millet+30% higher seed rate and T 4: Recommended package for bot the hcrops+Intercropping of clusterbean in paired rows of pearl millet. Incorporation of FYM 10 t/ha during the kharif season in pearl millet and 30% higher seed rate alongwith recommended package of practices resulted in increased grain yield of pearl millet as well as wheat leading to maximum cropping system productivity, profitability and water productivity. Incorporation of FYM 10 t/ha during the kharif season in pearl millet also increased yield of both the crops, while intercropping of clusterbean in paired rows of pearl millet resulted in increase of pearl millet yield only.
  • Authors:
    • Komecki, T. S.
    • Balkcom, K. S.
    • Raper, R. L.
    • Arriaga, F. J.
    • Price, A. J.
    • Reeves, D. W.
  • Source: Journal of Cotton Science
  • Volume: 13
  • Issue: 4
  • Year: 2009
  • Summary: An integral component of conservation agriculture systems in cotton ( Gossypium hirsutum L.) is the use of a high-residue winter cover crop; however, terminating cover crops is an additional expense and planting into high-residue can be a challenge. An experiment was conducted using black oat ( Avena strigosa Schreb.), rye ( Secale cereale L.), and wheat ( Triticum aestivum L.) cover crops established in early November at three locations. In mid-April each year all winter cover crops were flattened with a straight-blade mechanical roller-crimper alone or followed by three rates of glyphosate (0.84, 0.42, 0.21 kg ae/ha). Additionally, glyphosate alone at each rate and a non-treated check were included to complete the factorial treatment arrangement. Cotton was then planted 3 weeks after treatments were administered following in-row sub-soiling at E.V. Smith and direct seeding at Tennessee Valley and Robertsdale. Results showed that rolling followed by reduced glyphosate rates as low as 0.42 kg ae/ha can effectively and reliably terminate mature cereal winter cover crops; thus maintaining cotton population and protecting growth. Additionally, reduced glyphosate rates applied as low as 0.84 kg ae/ha alone can effectively terminate immature cereal covers while conserving soil moisture. Rolling mature winter cereal cover crops will likely conserve more soil moisture compared to standing covers; however, rolling immature cereal cover crops provides no benefit. In 2005 at E.V. Smith and at Tennessee Valley in 2006, increasing glyphosate rate increased cotton yield likely due to less mature cereal covers at time of treatment application. However, the inclusion of glyphosate did not increase cotton yield for any other comparison.