• 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:
    • Bernards, M. L.
    • Wilson, R. G.
    • Jordan, D. L.
    • Wilcut, J. W.
    • Shaw, D. R.
    • Owen, M. D. K.
    • Weller, S. C.
    • Johnson, W. G.
    • Kruger, G. R.
    • Young, B. G.
  • Source: Weed Technology
  • Volume: 23
  • Issue: 1
  • Year: 2009
  • Summary: Corn and soybean growers in Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina, as well as cotton growers in Mississippi and North Carolina, were surveyed about their views on changes in problematic weeds and weed pressure in cropping systems based on a glyphosate-resistant (GR) crop. No growers using a GR cropping system for more than 5 yr reported heavy weed pressure. Over all cropping systems investigated (continuous GR soybean, continuous GR cotton, GR corn/GR soybean, GR soybean/non-GR crop, and GR corn/non-GR crop), 0 to 7% of survey respondents reported greater weed pressure after implementing rotations using GR crops, whereas 31 to 57% felt weed pressure was similar and 36 to 70% indicated that weed pressure was less. Pigweed, morningglory, johnsongrass, ragweed, foxtail, and velvetleaf were mentioned as their most problematic weeds, depending on the state and cropping system. Systems using GR crops improved weed management compared with the technologies used before the adoption of GR crops. However, the long-term success of managing problematic weeds in GR cropping systems will require the development of multifaceted integrated weed management programs that include glyphosate as well as other weed management tactics.
  • 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:
    • Németh, T.
    • Kismányoky, A.
    • Lehoczkya, É.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 40
  • Issue: 1/6
  • Year: 2009
  • Summary: The study was carried out in 2006 in Keszthely, on the soil tillage portion of a long-term experiment. In this experiment, a combination of three cultivation methods [no-till drill, disk tillage, conventional tillage (plowed)] and five nitrogen (N) rates (N 0: 0, N 1: 120, N 2:180, N 3: 240, and N 4: 300 kg N ha -1) were assessed. The trial was arranged in a split-plot design with four replications, and it was carried out during the first occurrence of maize in winter wheat-winter wheat-maize-maize rotation. Maize was sown on 10 May 2006; the weed survey was carried out using Balazs-Ujvarosi coenological method on 5 June 2006, after which weed control was implemented. Maize biomass of plants at the three to four leaf stage was determined at the same time. Sixteen weed species were identified in the no-till treatment, and 14 each in the in the conventional and the disk tillage treatments. Cultivation systems had a profound effect on the weediness of maize, with the lowest weediness occurring in the conventional tillage treatment. There was a strong interaction between N application and weed biomass that favored increased yield of maize over all cultivation treatments at higher N rates. The N content of weeds decreased as follows: conventional tillage < disc tillage < no-till.
  • Authors:
    • Rizzo, I.
    • Sarandón, S. J.
    • Sisterna, M. N.
    • Lori, G. A.
    • Chidichimo, H.
  • Source: Crop Protection
  • Volume: 28
  • Issue: 6
  • Year: 2009
  • Summary: Fusarium head blight (FHB) is a destructive disease of the world's wheat-growing areas. In Argentina, the area under reduced tillage has increased due to soil erosion that threatened productivity. The effect of conventional and no tillage systems on FHB combined with other agronomic practices such as nitrogen fertilization, and the influence of the environmental conditions was analysed under natural infection on different cultivars. Wheat trials were conducted in three consecutive years; maize was the previous crop in the first and wheat the previous crop in the subsequent two years of the study. The experimental design was a split plot, with tillage treatments (conventional tillage and no-till) as the main plots. Fertilizer treatments were applied as a range of urea concentrations. Fusarium head blight was observed in all three experimental years. Differences of disease expression among trials were associated with the environmental factors prevailing during the experiments. In the first year, with moderate weather conditions, the only interactions for FHB incidence were between no-till and urea split doses. Seedling emergence, seed health, thousand kernel weight and deoxynivalenol (DON) concentration did not differ suggesting that the fertilizers and genotypes did not affect disease susceptibility. Climatic conditions prevailing in the second year were more conducive to disease development and severe FHB infection was observed. Tillage and fertilization treatments did not affect the variables analysed. Only cultivars showed significant differences and DON values were high. In the third year, unfavourable conditions for disease development resulted in low disease levels and no effect or interaction among variables was observed. The results obtained would suggest that favourable weather conditions are likely to be more important than tillage practice and fertilizer treatments. Since soil conservation practices have been widely adopted in most areas of Argentina, an integrated used of all the available strategies should be considered to decrease FHB damage.
  • Authors:
    • Fernandes, C.
    • Cora, J. E.
    • Marcelo, A. V.
    • Martins, M. dos R.
    • Jorge, R. F.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 33
  • Issue: 2
  • Year: 2009
  • Summary: Decomposing crop residues in no-tillage system can alter soil chemical properties, which may consequently influence the productivity of succession crops. The objective of this study was to evaluate soil chemical properties and soyabean, maize and rice yield, grown in the summer, after winter crops in a no-tillage system. The experiment was carried out in Jaboticabal, Sao Paulo, Brazil on a Red Latosol (Oxisol), in a completely randomized block design, in strip plots with three replications. The treatments consisted of four summer crop sequences (maize monocrop, soyabean monocrop, soyabean/maize rotation and rice/bean/cotton rotation) combined with seven winter crops (maize, sunflower, oilseed radish, pearl millet, pigeon pea, grain sorghum and sunn hemp). The experiment began in September 2002. After the winter crops in the 2005/2006 growing season and before the sowing of summer crops in the 2006/2007 season, soil samples were collected in the layers 0-2.5; 2.5-5.0; 5-10; 10-20; and 20-30 cm. Organic matter, pH, P, K +, Ca 2+, Mg 2+, and H+Al were determined in each soil sample. In the summer soyabean/maize rotation and in maize the organic matter contents and P levels were lower, in the layers 0-10 cm and 0-20 cm, respectively. Summer rice/bean/cotton rotation increased soil K levels at 0-10 cm depth when sunn hemp and oilseed radish had previously been grown in the winter, and in the 0-2.5 cm layer for millet. Sunn hemp, millet, oilseed radish and sorghum grown in the winter increased organic matter contents in the soil down to 30 cm. Higher P levels were found at the depths 0-2.5 cm and 0-5 cm, respectively, when sunn hemp and oilseed radish were grown in the winter. Highest grain yields for soyabean in monoculture were obtained in succession to winter oilseed radish and sunn hemp and in rotation with maize, after oilseed radish, sunn hemp and millet. Maize yields were highest in succession to winter oilseed radish, millet and pigeon pea. Rice yields were lowest when grown after sorghum.
  • 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:
    • Rosculete, E.
    • Gheorghe, D.
    • Matei, G.
    • Imbrea, F.
    • Cojocaru, I.
  • Source: Research Journal of Agricultural Science
  • Volume: 41
  • Issue: 1
  • Year: 2009
  • Summary: Field studies were conducted in Romania, from 2006 to 2008, to determine the effect of rotations and fertilizer applications on the yield and quality of maize in irrigated sandy soils. The treatments comprised 3 years rotation (wheat, maize and soyabeans), 4 years rotation (wheat, lucerne, maize and soyabeans), wheat monoculture, maize monoculture, 2 years rotation (maize and wheat), 5 years rotation (wheat, lucerne, potato, maize and wheat), 3 years rotation (wheat, maize and groundnut), 6 years rotation (maize, groundnuts, wheat, sunflower, potato and wheat) and 4 years rotation (bean, wheat, maize and wheat) and fertilizer applications, i.e. 160 kg N and 80 kg P/ha, 80 kg N and 80 kg P/ha and control. Results showed that maize gave good seed yields, which varied between 4.5 q/ha on unfertilized variant and 38.5 q/ha in the 6 years rotation on 160 kg N and 80 kg P/ha. The most valuable rotations for maize were beans, soyabean, groundnuts or lucerne. Applying fertilizers in monoculture resulted only in small increases in production. The best variant with fertilizers was the 80 kg N and 80 kg P/ha, which increased the yields of all rotations used compared to the control. On all the rotations studied, the nitrogen fertilizer application improved the N content of maize seeds and directly increased the protein content, while other macro- and microelements in maize seeds registered small fluctuations, some of which were considered as constant no matter what kind of rotation was used.
  • 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.
  • Authors:
    • Haller, W. T.
    • Mudge, C. R.
  • Source: Weed Technology
  • Volume: 23
  • Issue: 1
  • Year: 2009
  • Summary: The effects of flumioxazin in irrigation water were evaluated on four row crop species (corn, cotton, soybean, and wheat) and three ornamental species (begonia, impatiens, and snapdragon). Plants were overhead irrigated one time with flumioxazin at concentrations of 0, 10, 25, 50, 100, 200, 400, 800, 1,600, and 3,200 g ai/L in water equivalent to 1.27 cm. Ornamental plant tolerances on the basis of a 10% reduction in dry weight (effective concentration 10 [EC 10]) were as follows: impatiens (40)