• Authors:
    • Gladders, P.
    • Ellis, S.
    • Cook, S.
    • Berry, P.
    • Twining, S.
    • Wynn, S.
    • Clarke, J.
  • Source: HGCA Research Review
  • Issue: 70
  • Year: 2009
  • Summary: This report reviews the most important scenarios that could affect the availability of pesticides (fungicides, herbicides, insecticides and rodenticides) for use in wheat, winter barley, spring barley, oats and oilseed rape, and describes the effects of reduced pesticide availability as an outcome of the revision of Directive 91/414/EEC on weeds, pests and diseases they control, and on the resultant level of production and value that the crop could achieve. The analysis focused on changes in yield and quality, and the area affected, taking into account simple changes in management to mitigate the problems, such as changes in cultivation, cultivars, sowing rate and planting date.
  • Authors:
    • Pishbin, Y.
    • Lack, S. H.
    • Dadnia, M. R.
    • Modhej, A.
  • Source: Crop Research (Hisar)
  • Volume: 37
  • Issue: 1-3
  • Year: 2009
  • Summary: Diversification and continuous cropping have largely been a consequence of soil moisture saved through the adoption of conservation tillage. Consequently, weed communities have changed and, in some cases, become resistant to commonly used herbicides, thus increasing the complexity of managing weeds. The main plots contain cutivars in two levels and sub-plots contain rye grass and wild oat with 0, 25 and 50 density. Utilizing the principle of varying selection pressure to keep rye grass and wild oat communities off balance has reduced weed densities, minimized crop yield losses, and inhibited adverse community changes towards difficult-to-control species. Varied selection pressure was best achieved with a diverse cropping system where crop seeding date, perennation, and species and herbicide mode of action and use pattern were inherently varied. Approaches to cropping systems, including balancing rotations between cereal and broadleaf crops, reducing herbicide inputs, organic production, and the use of cover crops and perennial forages, are discussed in light of potential systems-level benefits for weed management.
  • Authors:
    • Buschman, L. L.
    • French, B. W.
    • Currie, R. S.
    • Davis, H. N.
  • Source: Southwestern Entomologist
  • Volume: 34
  • Issue: 1
  • Year: 2009
  • Summary: This study examined how land management practices can affect the abundance of several arthropods commonly found in agriculture. This work was done in plots that had been subjected to three successive years of an agronomic experiment that evaluated the effects of a wheat, Triticum aestivum L., cover crop or no cover crop on weed and water management. After the third growing season, pitfall traps were installed and arthropods were collected and identified. At one location, carabids (Coleoptera: Carabidae) were identified to genus. Four of the genera ( Amara, Anisodactylus, Harpalus, and Calathus) were more common under no-till conditions. Only one genus ( Stenolophus) was more common in tilled plots. Five genera ( Amara, Bradycellus, Scarites, Stenolophus, and Calathus) were more common in plots with a history of more weeds caused by less herbicide use. Carabids were not more abundant in plots with fewer weeds after herbicides had been applied. Past presence of a winter cover crop never reduced carabid numbers, but significantly increased members of two genera ( Harpalus and Poecilus). As a group, carabids at one location were more common in plots without a history of a cover crop. At another location, more carabids were in tilled than nontilled plots. Crickets (Orthoptera: Gryllidae) were more common under no-till conditions. At all locations, wolf spiders (Araneae: Lycosidae) were more common in plots with no tillage and a previous cover crop. Results suggested that surface residues affected carabids, wolf spiders, and crickets.
  • Authors:
    • Tarau, D.
    • Borza, I.
    • Dicu, D.
  • Source: Research Journal of Agricultural Science
  • Volume: 41
  • Issue: 2
  • Year: 2009
  • Summary: This study was conducted on a cambic chernozem in the Banat-Crisana Plain (Romania) to determine the quantitative and qualitative influence of tillage and fertilizer modifications made on the agroecosystem level on wheat, maize and soyabeans. The treatments include with and without deep soil working, conventional and no-tillage, and with (P1, N 80P 80K 80; P2, N 160P 80K 80) and without fertilizer application. Wheat was sown in 17 October 2007 and harvested in 28 June 2008. Maize was sown in 20 April 2008 and harvested in 27 Septerm 2008. Soyabean was sown 22 April 2008 and harvested in 11 October 2008. The field under the no-till system was maintained with more weeding than the conventional tillage. In terms of the evolution of soil humidity, more uniform values were obtained in the soil profile of the no-till system, while a low increase in soil water content was observed in the fields with deep working of soil. For wheat, the highest yield (4579 kg/ha) was obtained from the no-till system without deep working of the soil with P2 treatment, while the lowest yield (3475 kg/ha) was obtained from the conventional tillage system with deep soil working without fertilizer. For maize, the highest yield (5749 kg/ha) was obtained under the no-till system without deep working of soil with P2 treatment, while the lowest yield (3415 kg/ha) in classic system with deep work of soil without fertilizer. For soyabeans, the highest yield (1988 kg/ha) was obtained from the conventional tillage system without deep working of soil with P2 treatment, while the lowest (880 kg/ha) was obtained from the no-till system with deep working of soil without fertilizer treatment.
  • Authors:
    • Ralisch, R.
    • Nakashima, P.
    • Gasparetto, N. V. L.
    • Domingos, M. M. M.
    • Tavares Filho, J.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 33
  • Issue: 6
  • Year: 2009
  • Summary: Structural changes caused by management systems to soil can result in compaction and may change crop root development. With the aim to evaluate the effects of the farming systems on the soil structure by qualitative (cultural profile) and quantitative (soil density) methodologies, a field study was carried out in Maringa, state of Parana, Brazil (23degrees29′S, 51degrees59′W). A conventional tillage system with crop succession of corn ( Zea mays L.) and soybean ( Glycine max) and a no-till system with crop rotation of wheat ( Triticum spp.), corn ( Zea mays L.), common bean ( Phaseolus vulgaris), black oats ( Avena strigosa), and soybean ( Glycine max) established for more than 20 years were evaluated. An area under natural forest near the experimental field was evaluated as reference. After the description of the cultural (soil) profile, deformed samples were collected from the homogeneous soil volumes: two samples under forest, two samples in the no-till system and three samples in the conventional system. The physical and morphologic analyses of the soil structures of the layers 0-20 and 20-40 cm showed: (a) the two different tillage system promoted distinct depths of anthropic horizons; (b) the soil structure affected root distribution; (c) soil compaction under conventional system occurred in vertical and horizontal directions (d) soil structure was best under the no-till system; (e) the cultural profile methodology is efficient in soil morphology evaluations.
  • Authors:
    • Sabau, N. C.
    • Domuta, C.
    • Borza, I.
    • Bandici, G.
    • Samuel, A.
    • Ciobanu, C.
    • Ardelean ,I.
    • Ciobanu, G.
    • Sandor, M.
    • Domuta, C.
    • Brejea, R.
    • Vuscan, A.
  • Source: Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture
  • Volume: 66
  • Issue: 1
  • Year: 2009
  • Summary: Field studies were conducted in Oradea, Romania, from 2003 to 2008, in a long term trial placed in 1990 on preluvosoils. The climate indicator de Martonne aridity index (IdM) was used for quantification of the correlation between climate and wheat yield in unirrigated and irrigated conditions and a new class called arid was used for climate index characterization. Maintaining the soil water reserve on 0-50 cm depth between easily available water content and field capacity using the irrigation determined the increase of the IdM values for period IV-VI with 79% in 2003, 73% in 2004, 36% in 2005, 16% in 2006, 162% in 2007 and with 131% in 2008. Using the irrigation and the improvement of the microclimate conditions determined to obtain the yield gains, showed very significant results every year and every crop rotation studied, both in unirrigated and irrigated conditions. The smallest wheat yields were obtained in monocrop and the biggest in the wheat-maize-soyabean rotation. In the all 3 rotations, the direct links statistically assured were registered between the values of the IdM and yields in unirrigated and irrigated wheat. These correlations sustained the need of the irrigation in wheat from Crisurilor Plain. Correlation between the IdM was stronger in the wheat-maize-soyabean rotation compared to the wheat-maize rotation and with wheat monocrop. As a consequence, rotation of wheat-maize-soyabean was recommended because the climate and microclimate conditions were better used.
  • Authors:
    • Bara, C.
    • Sabau, N. C.
    • Domuta, C.
    • Borza, I.
    • Bara, V.
    • Samuel, A.
    • Ardelean, I.
    • Bara, L.
    • Ciobanu, G.
    • Sandor, M.
    • Domuta, C.
    • Brejea, R.
    • Vuscan, A.
  • Source: Analele Universităţii din Oradea, Fascicula: Protecţia Mediului
  • Volume: 14
  • Year: 2009
  • Summary: The paper is based on the research carried out during 2003-2008 in a long term trial placed in 1990 on the preluvosoil from Oradea. Climate indicator "de Martonne aridity index" (IdM) was used for quantification the correlation between climate and wheat yield in unirrigated and irrigated conditions and new class called "arid" was purposed for climate index characterization. Maintaining the soil water reserve on 0-50 cm depth between easily available water content and field capacity using the irrigation determined the increase of the IdM values for period IV-VI with 79% in 2003, 73% in 2004, 36% in 2005, 16% in 2006, 162% in 2007 and with 131% in 2008; using the irrigation and the improvement of the microclimate conditions determined to obtain the yield gains, very significant every year and every crop rotation studied; both in unirrigated conditions and in irrigated conditions, the smallest yields wheat were obtained in monocrop and the biggest in the wheat-maize-soybean crop rotation; in the all three crop rotation, the direct links statistically assured were registered between the values of the De Martonne aridity index and yields in unirrigated and irrigated wheat. These correlations sustain the need of the irrigation in wheat from Crisurilor Plain; correlation between De Martonne aridity index is stronger (R 2=0.7361 xx) in the wheat-maize-soybean crop rotation in comparison with wheat-maize crop rotation (R 2=0.6215 x) and with wheat monocrop (R 2=0.6105 x). As consequence, crop rotation of wheat-maize-soybean is recomanded because the climate and microclimate conditions are better use.
  • Authors:
    • Swanton, C. J.
    • Tardif, F.
    • Hamill, A. S.
    • Sikkema, P. H.
    • Gulden, R. H.
  • Source: Weed Science
  • Volume: 57
  • Issue: 6
  • Year: 2009
  • Summary: Glyphosate-resistant (GR) crops have been adopted rapidly since their commercial introduction, and with the increase in commercially available crops resistant to glyphosate, continuous use of the same herbicide mode of action is now possible in some crop rotations. A 6-yr study was initiated to investigate the effects of conventional herbicides compared with continuous use of gyphosate in GR or Roundup Ready corn and GR soybean in a corn-soybean and a corn-soybean-winter wheat rotation. Individual experiments were fully phased and established at three locations under conventional tillage (CT) and at two locations under no-tillage (NT). Results indicated that midseason weed ground cover was lower when weeds were controlled with glyphosate; however, in most cases, this did not result in improved corn or soybean yields. Within locations, species richness, which strongly influenced other diversity indicators, was most affected by the herbicide treatments. Including winter wheat in the crop rotation had little effect on corn and soybean weed ground cover, density, and community structure and only affected soybean yield. Moreover, no effects of herbicide system used in previous corn and soybean were observed in winter wheat, with the exception of species diversity in NT, where species diversity tended to be greater when weeds in previous corn and soybean were treated with conventional herbicides. After 6 yr, the effects of continuous use of GR crops in rotation were similar to those reported in previous Studies; however, continued monitoring and longer-term investigations of these systems are necessary to detect the early stages of development of herbicide-resistant biotypes.
  • Authors:
    • Gao, H. W.
    • Liu, L. J.
    • Li, H. W.
    • Wang, Q. J.
    • He, J.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: In the annual double cropping areas of North China Plain, low crop yield and water availability are the main limiting factors to crop production. Conservation tillage has been proposed to improve water conservation and sustain soil productivity. The objectives of the study were to compare conservation tillage (CT) with conventional tillage (CV) under the current double cropping system of corn-winter wheat in the Hebei, North China Plain. The field study consisted of eight conservation tillage treatments and two conventional tillage treatments, with different surface ground cover (0%, 50% and 100%). The tillage treatments consisted of no-till, subsoiling, rototilling and plowing. The CT treatments maintained soil temperatures that were approximately 0.4degreesC greater during cold condition and about 0.5degreesC lower during warm condition at 5 and 10 cm soil depths than the CV treatments, respectively. The greatest differences were achieved by the double no-till system with 100% residue cover treatment in terms of soil temperature and crop growth. Winter wheat yield and water use efficiency (WUE) were improved by 6.7% and 30.1% with CT compared to the CV treatments, and for corn, 8.9% and 6.8%, respectively. We conclude that conservation tillage for the annual double cropping system is feasible, and the double no-till with 100% residue cover is the most effective way of improving crop yields and WUE on the North China Plain.
  • Authors:
    • Reisenauer, P. E.
    • Kennedy, A. C.
    • Stubbs, T. L.
    • Burns, J. W.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 3
  • Year: 2009
  • Summary: Cropping systems in the dryland farming region of eastern Washington State are dominated by winter and spring wheat ( Triticum aestivum L.) and spring barley ( Hordeum vulgare L.). Excessive levels of residue may be an obstacle in the adoption of conservation farming systems. Decomposition of cereal crop residues is associated with fiber and nutrient content, and growers have observed differences in decomposition among cultivars; however, little information exists on their residue characteristics. Cultivars of spring barley (SB), spring wheat (SW), and winter wheat (WW) grown at four locations over two crop years were analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), C, and N contents, and winter wheat decomposition was tested in a laboratory incubation study. Acid detergent lignin was highest in spring barley (9.9%), and least in winter wheat (9.2%) and hard white spring wheat (9.5%). Fiber components and nutrient content varied by location, precipitation zone, and cultivar. Residue in the drier year of the study had lower NDF, ADF, ADL, C, and C/N ratio. Foot rot ( Fusarium spp.) - resistant winter wheat cultivars had higher NDF, ADF, and ADL than susceptible cultivars. Laboratory incubation studies showed decomposition of winter wheat straw in soil was correlated with ADF ( R2>0.66, P=0.002) and total N ( R2>0.67, P=0.04). Fiber and nutrient characteristics of residue from wheat and barley cultivars currently produced in the Pacific Northwest can be used to predict residue decomposition in cropping systems that conserve soil and water, and enhance build-up of organic matter.