• Authors:
    • Bayer, C.
    • Vieira, R. C. B.
    • Fontoura, S. M. V.
    • Ernani, P. R.
    • Moraes, R. P. de
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 34
  • Issue: 6
  • Year: 2010
  • Summary: Little is known about the agronomic effectiveness of phosphate rocks in high-yielding crop rotation systems under no-till in the Center-South of the state of Parana, Brazil. This field study was undertaken to compare the effectiveness of rock phosphates and soluble P fertilizers to increase the yield of several annual crops grown in two consecutive triennial crop-rotation cycles under no-tillage. The experiment was carried out in an Oxisol, in Guarapuava, PR, from 2000 until 2006. Two phosphate rocks (PR - Gafsa and Arad) and a soluble P fertilizer (TSP - triple superphosphate) were broadcast over the soil surface at rates of 0, 40, 80 and 160 kg ha -1 P 2O 5, at the beginning of the first and the second rotation cycle of the triennial crops (oat, maize, wheat, soybean, barley and soybean). With exception of barley, crop yields were not affected in the first rotation cycle by any phosphate fertilizer regardless of type and rate, probably due to the high P contents available in the soil (8.7 mg dm -3 in the 0-10 cm layer). In the second rotation cycle, when soil available P was 4.1 mg dm -3; P application at oat sowing increased the yield of summer crops by 11% and of winter crops by 20%. The yield increment was lowest for maize (8%) and highest for barley (44%). In this cycle, TSP resulted in higher yield than PR, though only for winter crops (oat, wheat and barley), in a mean of 11%, with no difference between Gafsa and Arad. Water soluble fertilizer (TSP) was more efficient than phosphate rocks in soils under no-till system both in the short and long term. Nevertheless, it is not necessary to apply phosphates for high yields in soils with high available P contents under no-till, except for species with high P requirement, e.g., barley.
  • Authors:
    • Petit, S.
    • Bretagnolle, V.
    • Dessaint, F.
    • Chauvel, B.
    • Gaba, S.
  • Source: Agriculture, Ecosystems and Environment
  • Volume: 138
  • Issue: 3-4
  • Year: 2010
  • Summary: There is empirical evidence that landscape composition and structure can affect the distribution and long-term dynamics of the organisms that live in it. Weeds are no exception and in this paper, we investigated how weed richness and diversity in 123 winter wheat fields within a small agricultural region were affected by the landscape surrounding each field (radii ranging from 100 to 1000 m) and the field properties such as its size and the preceding crop. Landscape was described by its proportion (cover of spring crops, winter crops, woodland, grassland, set-aside) and its structure (number of fields, number of land use types). Akaike criterion-based models indicated that variations in weeds were best explained at the 200 m radius. At that scale, hierarchical partitioning shows that the independent contributions of field level and landscape level variables were significant for two variables. Weed richness and weed diversity increased significantly as field size decreased and as the number of fields within 200 m increased. This suggests that weed richness and diversity are higher in landscapes that have a finer grain, probably because these landscapes offer more habitat heterogeneity within cultivated areas and contain more crop edges that can shelter many weed species.(C) 2010 Elsevier B.V. All rights reserved.
  • Authors:
    • Radmann, E. B.
    • Casagrande Junior, J. G.
    • Carpena Carvalho, F. L.
    • Gomes, C. B.
  • Source: Revista Brasileira de Fruticultura
  • Volume: 32
  • Issue: 1
  • Year: 2010
  • Summary: In a field naturally infested with ring nematode (Mesocriconema xenoplax), green covering were tested for their suppressing potential in winter and summer crops comparing to plots kept in fallow lands. Tree crop rotation system with the same plant species tested before (black oat/pig bean/millet/forage radish; forage radish/millet/white oat/corn; and white oat/dwarf velvet bean/wheat/sorghum) were evaluated for suppression potential to nematode M xenoplax for two years, using as control, plots that were kept in fallow lands. The experiments were conducted in the field in a randomized block design with six repetitions. Before and after the establishment of each plot, the nematode populations were evaluated on the number of M xenoplax/100cm3 of soil and the reproduction factor (RF=final population/initial population) of the ring nematode, where RF1,00, favoring of the reproduction. Most of the crops analyzed were unfavorable host (RF
  • Authors:
    • Gunter, C. C.
  • Source: ISHS Acta Horticulturae IV International Symposium on Ecologically Sound Fertilization Strategies for Field Vegetable Production
  • Issue: 852
  • Year: 2010
  • Summary: Efforts are being made to reduce the negative impacts that high intensity vegetable production can have on the soil. Soil nutrient removal and soil compaction due to heavy equipment can lead to long lasting problems in future production cycles. Producers are beginning to look at the beneficial effects that cover crops can have on soil tilth and fertility. Three rotational cover crop areas were established on the Southwest Purdue Agriculture Center in Vincennes, Indiana and each area was divided into four cover crop plots, no-till wheat, clover, oilseed radish and a bare ground control. Processing tomatoes, sweetcorn and snap beans were planted across the four cover crop plots within each rotational area. Two varieties of each type of vegetable were grown in each cover crop. Processing tomatoes had significantly less yield in the no-till wheat cover crop compared to the other three cover crops. There were also a higher proportion of green and turning fruit in that treatment. Snap beans showed significantly higher yields when grown in the oilseed radish and clover cover crops. Sweetcorn had significantly shorter ear length when grown in the no-till wheat cover crop. Varietal differences exist with cover crops, suggesting that some varieties perform better than others when using a specific cover crop.
  • Authors:
    • Kanae, S.
    • Inuzuka, T.
    • Hanasaki, N.
    • Oki, T.
  • Source: Journal of Hydrology
  • Volume: 384
  • Issue: 3/4
  • Year: 2010
  • Summary: The concept of virtual water, which is the volume of water consumption required to produce commodities traded to an importing or exporting nation (or any region, company, individual, etc.), is a useful complement to water resource analyses of water availability and use by region. Identifying the source of virtual water, such as precipitation (green water) and irrigation water (blue water), further enhances this concept because each differs in the level of sustainability and opportunity cost. Recent improvements in global hydrological models consisting of both physically based hydrological and anthropogenic activity modules enabled us to simulate the virtual water content of major crops consistent with their global hydrological simulation. Enhancing one of these models, called H08, we were able to assess two major sources of virtual water flow or content simultaneously: green water and blue water. Blue water was further subdivided into three subcategories ( i.e., streamflow, medium-size reservoirs, and nonrenewable and nonlocal blue water). We conducted a global hydrological simulation for 15 years from 1985 to 1999 at a spatial resolution of 0.5degrees * 0.5degrees (longitude and latitude). Total precipitation on land was 113,900 km 3 yr -1, with 72,080 km 3 yr -1 on average evaporating in the period 1985-1999. Green water evapotranspiration from rainfed and irrigated cropland and blue water evapotranspiration from irrigated cropland was estimated at 7820, 1720, and 1530 km 3 yr -1, respectively. Next, using global trade data for 2000 and the simulated virtual water content of major crops, the virtual water flow was estimated globally. Our results indicated that the global virtual water export ( i.e., the volume of water that an exporting nation consumes to produce the commodities that it trades abroad) of five crops (barley, maize, rice, soybean, and wheat) and three livestock products (beef, pork, and chicken) is 545 km 3 yr -1. Of the total virtual water exports, 61 km 3 yr -1 (11%) are blue water ( i.e., irrigation water) and 26 km 3 yr -1 (5%) are nonrenewable and nonlocal blue water.
  • Authors:
    • Gaweda, D.
    • Harasim, E.
  • Source: Annales Umcs, Agricultura
  • Volume: 65
  • Issue: 1
  • Year: 2010
  • Summary: The objective of the study was to assess the effect of catch crops on the yield and energetic efficiency of the main cereal crop grown under monoculture. The study was carried out in the years 2006-2008 at Uhrusk experiment farm. The trial was localized on a mixed rendzina soil, of medium depth, developed from chalk limestone. The experiment included spring cereals such as wheat, barley and oats as well as stubble catch crops: non-catch crop control, white mustard, blue phacelia, winter oilseed rape and a legume mixture - narrow-leaved lupin+field peas. The highest yield increase over the non-catch crop control (9.4%) was found when phacelia was grown as a catch crop after wheat. The lowest yield increment occurred in barley grown after legumes (ca. 8%) and in oats gown after phacelia and oilseed rape (ca. 7%). The energetic efficiency of cereal production was more related to the main cereal crop than to the catch crop. The production of barley and oats had a higher energetic efficiency (4.71 and 4.65, respectively) than that of wheat (3.84). The use of catch crops lowered but to a small degree the energetic efficiency of spring cereal production.
  • Authors:
    • Döll, P.
    • Siebert, S.
  • Source: Journal of Hydrology
  • Volume: 384
  • Issue: 3-4
  • Year: 2010
  • Summary: Crop production requires large amounts of green and blue water. We developed the new global crop water model GCWM to compute consumptive water use (evapotranspiration) and virtual water content (evapotranspiration per harvested biomass) of crops at a spatial resolution of 5′ by 5′, distinguishing 26 crop classes, and blue versus green water. GCWM is based on the global land use data set MIRCA2000 that provides monthly growing areas for 26 crop classes under rainfed and irrigated conditions for the period 1998-2002 and represents multi-cropping. By computing daily soil water balances, GCWM determines evapotranspiration of blue and green water for each crop and grid cell. Cell-specific crop production under both rainfed and irrigated conditions is computed by downscaling average crop yields reported for 402 national and sub-national statistical units, relating rainfed and irrigated crop yields reported in census statistics to simulated ratios of actual to potential crop evapotranspiration for rainfed crops. By restricting water use of irrigated crops to green water only, the potential production loss without any irrigation was computed. For the period 1998-2002, the global value of total crop water use was 6685 km 3 yr -1, of which blue water use was 1180 km 3 yr -1, green water use of irrigated crops was 919 km 3 yr -1 and green water use of rainfed crops was 4586 km 3 yr -1. Total crop water use was largest for rice (941 km 3 yr -1), wheat (858 km 3 yr -1) and maize (722 km 3 yr -1). The largest amounts of blue water were used for rice (307 km 3 yr -1) and wheat (208 km 3 yr -1). Blue water use as percentage of total crop water use was highest for date palms (85%), cotton (39%), citrus fruits (33%), rice (33%) and sugar beets (32%), while for cassava, oil palm and cocoa, almost no blue water was used. Average crop yield of irrigated cereals was 442 Mg km -2 while average yield of rainfed cereals was only 266 Mg km -2. Average virtual water content of cereal crops was 1109 m 3 Mg -1 of green water and 291 m 3 Mg -1 of blue water, while average crop water productivity of cereal crops was 714 g m -3. If currently irrigated crops were not irrigated, global production of dates, rice, cotton, citrus and sugar cane would decrease by 60%, 39%, 38%, 32% and 31%, respectively. Forty-three per cent of cereal production was on irrigated land, and without irrigation, cereal production on irrigated land would decrease by 47%, corresponding to a 20% loss of total cereal production. The largest cereal production losses would occur in Northern Africa (66%) and Southern Asia (45%) while losses would be very low for Northern Europe (0.001%), Western Europe (1.2%), Eastern Europe (1.5%) and Middle Africa (1.6%). Uncertainties and limitations are discussed in the manuscript, and a comparison of GCWM results to statistics or results of other studies shows good agreement at the regional scale, but larger differences for specific countries.
  • Authors:
    • Evans, A.
    • Blummel, M.
    • Noble, A. D.
    • Ahmad, W.
    • Simmons, R. W.
    • Weckenbrock, P.
  • Source: Irrigation and Drainage Systems
  • Volume: 24
  • Issue: 1-2
  • Year: 2010
  • Summary: In 2006 a comprehensive sampling program was undertaken in two pre-selected peri-urban villages in Faisalabad, Pakistan to evaluate the soil and agronomic impacts of long-term (25-30 years) untreated wastewater re-use on wheat grain and straw yields and attributes of wheat straw fodder quality. Soil SAR, ESP, RSC and ECe were 63%, 37%, 31%, and 50% higher under wastewater (WW) as compared with canal water (CW) irrigated plots. Further, 2.7 and 6.65 fold increases in soil NO 3-+NO 2--N and Olsen-P were observed in WW as compared with CW irrigated plots. However, no significant differences in grain yield, wheat straw biomass, or fodder quality attributes were observed between WW and CW irrigated plots. In addition, for both CW and WW irrigated plots wheat straw, Cd and Pb concentrations were orders of magnitude below the EC Maximum permissible levels for Pb and Cd in feed materials and thus pose no threat to the fodder-livestock food chain. Further, elevated soil N associated with WW irrigated plots has a significant ( p
  • Authors:
    • Fortuna, A. M.
    • Kennedy, A. C.
    • Stubbs, T. L.
  • Source: Journal of Agricultural and Food Chemistry
  • Volume: 58
  • Issue: 1
  • Year: 2010
  • Summary: Residue from cultivars of spring wheat ( Triticum aestivum L.), winter wheat, and spring barley ( Hordeum vulgare L.) was characterized for fiber and nutrient traits using reference methods and near-infrared spectroscopy (NIRS). Calibration models were developed for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), carbon (C), sulfur (S), nitrogen (N), and C:N. When calibrations were tested against validation sets for each crop year, NIRS was an acceptable method for predicting NDF (standard error of prediction (SEP) 0.90) and ADF (SEP0.92) and moderately successful for ADL in 1 year of the study (SEP=0.44; R2=0.81) but less successful for C, S, N, and C:N ( R2 all <0.57). These results indicate that NIRS can predict the NDF and ADF of cereal residue from dryland cropping systems and is a useful tool to estimate residue decomposition potential.
  • Authors:
    • Hameed, M
    • Afzal, M
    • Rana, S. A.
    • Ruby, T.
  • Source: International Journal of Agriculture & Biology
  • Volume: 12
  • Issue: 6
  • Year: 2010
  • Summary: Arthropods are the most integral part of an agro-ecosystem, but the crop intensification practices are badly affecting these key components. Studies pertaining to biodiversity of arthropods in the cropland of two zones i.e., mixed crop zone (Faisalabad) and Cotton-Wheat zone (Multan) Punjab, Pakistan were conducted for a period of one year. The main focus was to collect, identify and compare the species richness and evenness. Sugarcane, Fodder, Wheat and Brassica were sampled round the year showed variations in species composition of their fauna in the two districts representing the two zones. Mixed-crop zone was highly diversified with respect to species and abundance of individuals per species. On the whole order Orthoptera was dominant followed by Araneae, Hemiptera, Coleoptera, Lepidoptera, Hymenoptera, Odonata, Diptera and Thysanoptera, Neuroptera, Prostigmata each represented by single species except Mantodea with two species. This data base will be helpful in future ecological pest management strategies. The mixed-crop zone was found better than cotton-wheat zone with respect to faunal diversity that may be functional in keeping the sustainability of agro-ecosystem intact.