• Authors:
    • Xu, Y. L.
    • Jiang, J. H.
    • Conway, D.
    • Lin, E.
    • Holman, I.
    • Xiong, W.
    • Li, Y.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 135
  • Issue: 1/2
  • Year: 2010
  • Summary: Climate scenarios from a regional climate model are used to drive crop and water simulation models underpinned by the IPCC A2 and B2 socio-economic development pathways to explore water availability for agriculture in China in the 2020s and 2040s. Various measures of water availability are examined at river basin and provincial scale in relation to agricultural and non-agricultural water demand and current and planned expansions to the area under irrigation. The objectives are to understand the influences of different drivers on future water availability to support China's food production. Hydrological simulations produce moderate to large increases in total water availability in response to increases in future precipitation. Total water demand increases nationally and in most basins, but with a decreasing share for agriculture due primarily to competition from industrial, domestic and municipal sectors. Crop simulations exhibit moderate to large increases in irrigation water demand which is found to be highly sensitive to the characteristics of daily precipitation in the climate scenarios. The impacts of climate change on water availability for agriculture are small compared to the role of socio-economic development. The study identifies significant spatial differences in impacts at the river basin and provincial level. In broad terms water availability for agriculture declines in southern China and remains stable in northern China. The combined impacts of climate change and socio-economic development produce decreases in future irrigation areas, especially the area of irrigated paddy rice. Overall, the results suggest that there will be insufficient water for agriculture in China in the coming decades, due primarily to increases in water demand for non-agricultural uses, which will have significant implications for adaptation strategies and policies for agricultural production and water management.
  • Authors:
    • Kelley, J.
    • Oliver, D.
    • Gbur, E. E.
    • Brye, K. R.
    • Amuri, N.
  • Source: Weed Science
  • Volume: 58
  • Issue: 3
  • Year: 2010
  • Summary: Management practices and cropping systems that serve as integrated weed management practices, and at the same time can contribute to improved soil quality, will be important for the sustainability of agricultural production systems. The objective of this study was to assess weed species population density under contrasting tillage (conventional tillage [CT] and no tillage [NT]), residue burning (burn and no burn), and residue level (low and high) treatments after 5 and 6 yr of consistent management in a wheat-soybean double-crop production system. A field experiment was conducted from fall 2001 to fall 2007 in the Mississippi River Delta region of eastern Arkansas on a Calloway silt-loam. Weed assessments were conducted twice during the soybean growing season, before (early season) and after herbicide application (late season) in 2006 and 2007. Total weed density was greater under CT (513 plants m(-2)) than under NT (340 plants m(-2)) early in the growing season in 2006, but was greater under NT than CT late in the season in 2007, suggesting that the effectiveness of glyphosate on total weeds differs between CT and NT. Averaged across residue levels, grass species density was greatest in the NT burn (68 to 167 plants m(-2)) combination and lowest in the NT no-burn (41 to 63 plants m(-2)) early in the growing season in both years. Broadleaf density was greater early (200 to 349 plants m(-2)) than late (18 to 20 plants m(-2)) in the growing season under both CT and NT in 2006, but in 2007 broadleaf density did not differ by tillage treatment between seasons. Perennial weed density was greater in the burn (99 plants m(-2)) than in the no-burn (59 plants m(-2)) treatment in 2006. No tillage, no burning, and a high residue level appeared to contribute to the suppression of most weed species without reducing herbicide efficiency.
  • Authors:
    • Hoffmann, A. A.
    • Umina, P. A.
    • Weeks, A. R.
    • Arthur, A. L.
  • Source: Experimental and Applied Acarology
  • Volume: 52
  • Issue: 2
  • Year: 2010
  • Summary: Balaustium medicagoense and Bryobia spp. have recently been identified as emerging pests of winter crops and pastures in Australia. These mites have a high natural tolerance to currently registered pesticides, highlighting the need to develop alternative control strategies such as cultural controls which require an understanding of plant associations. In shade-house experiments, Bryobia spp. survived and reproduced successfully on pasture, lupins and oats, but progeny failed to reach the adult stage on canola and wheat. Balaustium medicagoense progeny failed to produce a generation on any crop but parental adults survived a few months on all crops, particularly wheat. Bryobia spp. damaged canola, pasture and lupins, but caused minimal damage to oats and wheat, whereas Ba. medicagoense caused considerable damage to wheat and lupins, but only moderate damage to canola, oats and pasture. Field survey data, taken from approximately 450 sites across southern Australia, combined with analysis of historical pest reports, suggest broadleaf crops such as canola, lucerne, lupins and weeds appear particularly susceptible to attack by Bryobia species. Balaustium medicagoense was more commonly found on cereals and grasses, although they also attacked broadleaf crops, particularly canola, lucerne and lupins. These findings show that the mites have the potential to be an important pest on several winter grain crops and pasture, but there are important differences that can assist in management strategies such as targeted crop rotations.
  • Authors:
    • Bartosik, R.
  • Source: Julius-Kühn-Archiv
  • Issue: 425
  • Year: 2010
  • Summary: Concerning grain production, South America is divided in two main regions: (1) the Mercosur region (Argentina, Brazil, Uruguay and Paraguay) which produces more than 250 million tonnes of grains and oilseeds, and (2) the Andes Mountain region countries, which are net importers of these products. The main challenges related to grain postharvest that South America is facing are to minimize the quality and quantity losses; improve the food safety; enhance the capability for segregation and traceability of identity preserved (IP) grains; and incorporate technology to maintain the overall efficiency of the postharvest system. Among the critical points affecting the efficiency of the system are the shortage of permanent storage capacity; large storage structures which affects the segregation of IP grains; deficient transportation system (roads and railroads); poor management of integrated pest control system; and unsatisfied demand of formal and informal education in suitable grain postharvest technologies and practices. However, the region remains highly competitive in producing and delivering food for the rest of the world and it has demonstrated high capacity for incorporating cost efficient grain handling technologies. As a result, one of the main changes in the region was the appearance of the silobag system for temporary storage of dry grain and oilseeds. Each silobag can hold approximately 200 tonnes of wheat and with the available handling equipment is quite simple to load and unload. During the 2008 harvest season, more than 33 million tonnes of grain were stored in these plastic bags in Argentina (including corn, soybean, wheat, sunflower, malting barley, canola, cotton seed, rice, lentils, sorghum, beans and even fertilizers). The silobag technology is also being adopted not only in neighbor countries, but also in countries around the world such as the USA, Mexico, South Africa, Australia, Russia and Ukraine, among others.
  • Authors:
    • Maghirang, R. G.
    • Casada, M. E.
    • Boac, J. M.
    • Harner, J. P.,III
  • Source: Transactions of the ASABE
  • Volume: 53
  • Issue: 4
  • Year: 2010
  • Summary: Experimental investigations of grain flow can be expensive and time consuming, but computer simulations can reduce the large effort required to evaluate the flow of grain in handling operations. Published data on material and interaction properties of selected grains and oilseeds relevant to discrete element method (DEM) modeling were reviewed. Material properties include grain kernel shape, size, and distribution; Poisson's ratio; shear modulus; and density. Interaction properties consist of coefficients of restitution, static friction, and rolling friction. Soybeans were selected as the test material for DEM simulations to validate the model fundamentals using material and interaction properties. Single- and multi-sphere soybean particle shapes, comprised of one to four overlapping spheres, were compared based on DEM simulations of bulk properties (bulk density and bulk angle of repose) and computation time. A single-sphere particle model best simulated soybean kernels in the bulk property tests. The best particle model had a particle coefficient of restitution of 0.6, particle coefficient of static friction of 0.45 for soybean-soybean contact (0.30 for soybean-steel interaction), particle coefficient of rolling friction of 0.05, normal particle size distribution with standard deviation factor of 0.4, and particle shear modulus of 1.04 MPa.
  • Authors:
    • Domuta, C.
    • Sandor, M.
    • Bara, L.
    • Bara, C.
    • Bara, V.
    • Domuta, C.
    • Borza, I. M.
    • Brejea, R.
    • Vuscan, A.
  • Source: Analele Universităţii din Oradea, Fascicula: Protecţia Mediului
  • Volume: 15
  • Year: 2010
  • Summary: The paper based on the researche carried out in the Agricultural Research and Development Station Oradea in the long term trial placed in 1990 on a preluvosoil. Two factors were studied: crop rotation (maize-monocrop; maize-wheat; maize-soybean-wheat) and water regime (unirrigated and irrigated). In comparison with unirrigated and irrigated monocrop, in the maize-wheat crop and especially in the maize-soybean-wheat crop rotation very significant yield gains were obtained all the three years. The irrigation determined the yield gains very significant statistically every year and in every crop rotation. The smallest protein content and protein production were registered in the variant with maize monocrop and the biggest in the variant with wheat-maize-soybean crop. The irrigation determined the increase of the protein content.
  • Authors:
    • [Anonymous]
  • Source: XIIIeme Colloque International sur la Biologie des Mauvaises Herbes
  • Year: 2009
  • Summary: These proceedings contain 61 papers classified under sections on agroecology, ecology of weed communities, integrated weed management, herbicide resistance, and invasive plants. Specific topics covered include the following: reduction of weed growth by cutting and competition; evaluation of weed diversity; biodiversity of medicinal plant species in the segetal communities in the Opole region (Poland); simulation of insect resistance in gene flow study between Brassica napus and wild B. juncea; effects of the harvesting season of sugarcane on weed growth dynamic in La Reunion Island; impact of volunteer rape on the productivity of barley; relationship between biomass and seed production by Alopecurus myosuroides after herbicide treatment; weed emergence patterns in winter cereals under zero tillage in dry land areas; size and composition of the weed seed bank after 12 years of continuous application of different fertilizer systems; multi-criteria evaluation of cropping systems prototypes based on integrated weed management; a rapid test of glyphosate resistance in ryegrass; cross resistance in Sinapis alba to ALS-inhibiting herbicides; resistance to glyphosate in Europe; and herbicide-resistant weeds in Iran.
  • Authors:
    • Kuszewska, K.
    • Korniak, T.
  • Source: Herba Polonica
  • Volume: 55
  • Issue: 3
  • Year: 2009
  • Summary: The Avena genus covers nine species in Poland, including farmed common oat ( Avena sativa), wild oat ( A. fatua) - a dangerous spring cereal weed, and bristle (or black) oat ( A. strigosa Schreb.), a forgotten species. Bristle oat was a valuable component of common oat yield growing on the weakest soils, and it had a status of a crop plant in Poland and in many European countries till 1950s. Chemical analyses of bristle oat caryopses validated the high nutritive value of this species, which had been previously noted by the farmers of the Podhale region. On average, bristle oat contains 27-52% more protein, 14-27% more fat and 38-72% more sugars than common oat. It is good for human consumption in the form of flakes, flour and boiled grains. Bristle oat is witnessing a revival as a valuable farming species, and its crops are subsidized.
  • Authors:
    • Velykis, A.
    • Arlauskiene, A.
    • Maiksteniene, S.
    • Satkus, A.
  • Source: ZEMDIRBYSTE-AGRICULTURE
  • Volume: 96
  • Issue: 2
  • Year: 2009
  • Summary: A series of experiments was carried out during the period 1997-2004 to study the effects of crop rotations with a different proportion of winter and spring crops, various legume preceding crops and cover crops and their biomass use for green manure on weed infestation in cereals on a clay loam Endocalcari-Endohypogleyic Cambisol ( CMg-p-w-can) under North Lithuania's conditions. Crop rotations with prevailing winter crops predetermined the reduction in perennial weeds in cereals. The occurrence of weeds in cereals was determined by the weed incidence in the preceding crops tested: red clover ( Trifolium pratense L.), lucerne ( Medicago sativa L.) and vetch-oats ( Vicia sativa L., Avena sativa L.) mixture and by competitive ability of cereals. The biomass of clover and vetch-oat mixture incorporated as green manure tended to increase weed incidence in cereals. Undersowing of cover crops ( Trifolium pratense L., Lolium multiflorum Lam., Dactylis glomerata L.) tended to reduce the weed emergence in cereals, compared to the crops without undersowing. Undersown red clover performed best at suppressing weeds during the cereal post-harvest period. Its positive effect persisted in the following year after incorporation of red clover biomass for green manure. The effect of post-harvest sown cover crops ( Raphanus sativus L., Sinapis alba L.) on weed incidence in cereals was lower compared to undersown crops.
  • Authors:
    • Wise, M.
    • Schmitt, M.
  • Source: Cereal Chemistry
  • Volume: 86
  • Issue: 2
  • Year: 2009
  • Summary: beta-Glucan from cereal (barley and oat) grain and malt is easily determined using Calcofluor fluorescence in a microplate fluorimetre. The method is sensitive and scalable to cover a wide range of beta-glucan concentrations by simply adjusting the aliquot size used in the 96-well microplates. The microplate assay uses inexpensive reagents and commonly available instrumentation, obviating the need for investment in flow injection analysis instrumentation or commercial reagent kits, providing an attractive alternative to enzymatic kits or flow injection analysis systems.