• 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:
    • DorĂ©, T.
    • Lucas, P.
    • Faloya, V.
    • Montfort, F.
    • Motisi, N.
  • Source: Field Crops Research
  • Volume: 113
  • Issue: 3
  • Year: 2009
  • Summary: Biofumigation is increasingly viewed as a potentially useful technique for controlling soil-borne crop pathogens, but its efficacy has not systematically been demonstrated at field scale. We investigated the differences in efficacy observed in the field, by analysing the mechanisms by which a Brassica cover crop can act as a biofumigant crop in the prevention of soil-borne disease development. We hypothesised that the biofumigant crop might have a negative effect on soil-borne pathogens whilst growing, and that the pulverisation of this crop and the incorporation of its residues into the soil may enhance this effect. We tested this hypothesis by carrying out three field experiments in 2006, 2007 and 2008 in which Brassica juncea (brown mustard) was managed in different ways within a sugar beet-winter wheat rotation and analysing effects on sugar beet root rot caused by Rhizoctonia solani. Three treatments were studied: mustard pulled out at flowering (MP), mustard crushed at flowering and incorporated into the soil (MC) and bare soil (BS) as a control. We assessed the effect of each treatment on root rot incidence and severity at harvest. Over the 3 years of the experiment, disease incidence was significantly higher on BS plots than on the other plots and was significantly higher on MP plots than on MC plots. MC treatment gave a significantly lower mean conditional severity (severity calculated for diseased beets only) than the BS and MP treatments. Mustard residue incorporation was consistently effective at decreasing disease incidence from year to year (43, 44 and 47% efficacy, as determined by comparison with the disease incidence on BS plots, in 2006, 2007 and 2008, respectively), but the efficacy of growing mustard was variable (36, 16 and 39% efficacy in 2006, 2007 and 2008, respectively). These findings provide insight into the mechanisms by which biofumigant crops may affect soil-borne diseases. These findings have implications for the possible use of biofumigant crops as a biological method for controlling soil-borne diseases at the field scale. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Sim, R.
    • Maley, S.
    • Fletcher, A.
    • Ruiter, J. M. de
    • George, M.
    • de Ruiter, J. M.
  • Source: Proceedings of the New Zealand Grassland Association
  • Volume: 71
  • Year: 2009
  • Summary: Dairy industry strategies have demanded feeding systems with high productivity and high quality. A 45 t DM/ha annual target for feed production was addressed. Six crop sequence treatments were established in large plots (40*12 m) at Lincoln, Canterbury, in the first year of a 2-year experiment to determine practical upper limits for yield. Summer crops included maize, kale and whole crop barley and these were followed by combinations of winter crops (oats, Italian ryegrass, forage rape, tick beans and triticale). Crops were grown with minimal transition time to reduce potential yield losses, and with optimum nitrogen and irrigation management. Highest plot yield in the first annual crop cycle was 11.9 t DM/ha short of the 45 t DM/ha target. Best productivity was with a maize - triticale+tick bean (32.5 t DM/ha) sequence followed by maize - wheat (30.0 t DM/ha), barley - oats+Italian ryegrass (28.1 t DM/ha) and kale - triticale+tick bean (26.1 t DM/ha). Fertiliser management, crop water use in high input cropping systems are discussed together with practical issues around handling crops with large accumulated biomass.
  • Authors:
    • Klimek, S.
    • Steinmann, H-H
    • Ulber, L.
    • Isselstein, J.
  • Source: Weed Research
  • Volume: 49
  • Issue: 5
  • Year: 2009
  • Summary: Weed species diversity may benefit from organic farming due to enhanced temporal diversification of crop species in a rotation and omission of herbicide applications. However, in intensively managed conventional systems, little evidence exists as to what extent diversified crop rotations contribute to higher weed species richness. Using an on-farm approach, the effect of crop rotation (organic, conventional diverse (CD) and conventional simple (CS) crop rotations) and weed control (with vs. without) on weed species richness, cover, community composition and crop biomass, was analysed in 24 winter wheat fields. Weed species with beneficial functions for invertebrates and birds were analysed separately. Weed species richness was higher in the organic crop rotation, but did not differ between CD and CS crop rotations. Weed control treatment reduced species richness in both conventional rotations, but not in the organic one. Redundancy analyses revealed that crop rotation intensity accounted for the largest part of the explained variation in weed species composition. Results from the study indicate that the maintenance of weed species richness and conservation of species with important ecological functions requires not only temporal diversification of crop species in the rotation, but also an adjustment of weed control strategies.
  • Authors:
    • Steinbach, H. S.
    • Alvarez, R.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: The Argentine Pampas is one of the most important cropping regions of the World. Limited tillage systems, and specially no-till, had widespread in recent years, occupying actually around 70% of the surface devoted to annual crops. We review results produced in field experiments installed along the Pampas to determine the effect of the adoption of these tillage systems on some soil properties and crops yield. It was performed a meta-analysis of data from experiments where plow tillage (mouldboard plow), reduced tillage (chisel plow, disk plow or harrow disk) and no-till were compared. Treatments effects were contrasted by paired t-tests between groups of paired data. Soil bulk density and cone penetration resistance of the 0-20 cm layer were higher under limited tillage systems than under plow tillage. Increases of bulk density under no-till in comparison to plow tillage were generally small, averaging 4%, but cone penetration increased by 50% in many soils. The increase of bulk density was greater in soils of initial low bulk density. Neither bulk density increases nor cone penetration changes reached critical threshold for roots development. Aggregate stability and water infiltration rate were higher in soils subjected to limited tillage systems than under plow tillage. The improvement of aggregate stability was higher in poorer structured soils, with an average increase of 70% under no-till in relation to plow tillage. Under no-till infiltration rate doubled in average that of plow tillage. Soil water content during the critical periods of sowing and flowering was generally greater under limited tillage but, conversely, nitrate nitrogen levels were greater in plow tillage. Higher soil water content under no-till in relation to plow tillage may satisfied the evapotranspiration demand of 1-3 days of crops during the critical flowering period, being nitrate nitrogen in average 21 kg ha -1 lower under no-till. Soybean ( Glycine max (L.)-Merr.) yield was not affected by tillage system, meanwhile wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields were lower under reduced tillage and no-till than under plow tillage without nitrogen fertilization. Wheat and corn no-till yields were 10-14% lower that yields under plow tillage as a mean. When fertilizers were applied, wheat and corn yield differences between tillage treatments generally disappeared. The adoption of limited tillage systems in the Pampas leads to soil improvement but also generates the necessity of increase nitrogen fertilizers utilization to sustain yields of graminaceus crops.
  • Authors:
    • Gathala, M. K.
    • Singh, K. K.
    • Sharma, S. K.
    • Saharawat, Y. S.
    • Tetarwal, J. P.
    • Ladha ,J. K.
    • Gupta, R. K.
    • Jat, M. L.
    • Singh, S.
  • Source: ACIAR PROCEEDINGS
  • Issue: 127
  • Year: 2008
  • Summary: Resource-conserving technologies with double no-till practices represent a major shift in production techniques for attaining optimal productivity, profitability and water use in rice-wheat (RW) systems in the Indo-Gangetic Plain. Permanent raised beds (PRB) and double no-till with flat layouts are under evaluation for RW systems for a range of soils, climate, cultivars and seeding/crop establishment techniques (dry seeding, transplanting). To date, results have been inconsistent and systematic information on trials with PRB is lacking. Four researcher- and farmer-managed experiments were conducted with various tillage and crop establishment techniques for RW on PRB and flat layouts. The yield of rice on PRB was significantly lower than that on double no-till flat layouts, whereas wheat yield was highest on PRB. The total RW system yield with PRB was similar to that of other tillage and crop establishment techniques. However, irrigation and input (irrigation plus rain) water productivity (kg grain/m 3 of water) of both rice and wheat was much higher on PRB. In farmer-managed trials of transplanted basmati rice on PRB, profitability was highest on PRB (US$684/ha) and lowest with traditional practices (US$531/ha). In a researcher-managed long-term experiment, the soil physical properties (bulk density, mean weight diameter of aggregates, cone index and infiltration rate) improved significantly on PRB compared with the conventional puddled transplanted rice-tilled wheat system.
  • Authors:
    • [Anonymous]
  • Source: Muhle + Mischfutter
  • Volume: 145
  • Issue: 18
  • Year: 2008
  • Summary: The article describes harvest and yield details of the German cereals season 2008. All federal states of Germany are covered and all cereals including milling, feed, industrial and grain maize, but excluding silage and corn-cob-mix maize. In 2008, the total tonnage increased from 23% to 49 million tonnes. The highest yield increases, compared to the poor year 2007, were reported from the northern states, Mecklenburg-Vorpommern, Niedersachsen, Schleswig-Holstein and Nordrhein-Westfalen. Average winter wheat yields were 8.1 t/ha, winter barley 6.6 t/ha and triticale 6.0 t/ha. Spring barley was 4.9 t/ha and oats only 4.6 t/ha. Because of the large quantities, enough good quality milling wheat will be available. An outlook on the EU cereal harvest, the global and USA harvests in 2008 are given at the end of the paper.
  • Authors:
    • Wolfe, M.
    • Boyd, H.
    • Haigh, Z.
    • Jones, H.
    • Clarke, S.
  • Source: Cultivating the future based on science. Volume 1: Organic Crop Production. Proceedings of the Second Scientific Conference of the International Society of Organic Agriculture Research (ISOFAR), held at the 16th IFOAM Organic World Conference in Cooperatio
  • Year: 2008
  • Summary: Two seasons (2005/06 and 2006/07) of field experiments which aimed to study the suitability of new and established husked oat varieties, variety mixtures and a husked oat population for organic systems were established at two sites in the west and east of the UK. The ground cover and leaf area indices of the varieties had significant effects on final yields in the 2005/06. Mixtures generally yielded similarly to the means of component varieties but the mixtures in 2005/06 and 2006/07 had 25% and 18% less disease, respectively, than the average of the component varieties at one site.
  • Authors:
    • Ojeda Trejo, E.
    • Martinez Menes, M.
    • Prat, C.
    • Bravo Espinosa, M.
    • Medina Orozco, L.
    • Serrato Barajas, B.
  • Source: Agricultura Tecnica en Mexico
  • Volume: 34
  • Issue: 2
  • Year: 2008
  • Summary: In the upper part of Cuitzeo Lake watershed, Michoacan, Mexico, farmers use a traditional short-fallow production system. With this system, land is sown one year, and left without cultivation from one to three years for grazing. Tins system is used mainly on Andisols and Acrisols, and it is supposed to be associated with soil degradation due to low nutrient recycling level and to excessive tillage during the cultivation year. The objective of this study was to measure soil, nutrient and runoff losses under the traditional short-fallow system (AV), and under two alternatives systems: organic (O), and improved traditional (TM) systems. Research was carried out on an Acrisol in the Cointzio subwatershed, during three years under rainfed conditions on 1 000 m 2 runoff plots without replications. Results showed that soil losses under all systems were permissible (
  • Authors:
    • Scudamore, K.
  • Source: World Mycotoxin Journal
  • Volume: 1
  • Issue: 3
  • Year: 2008
  • Summary: The cereal food chain covers events from the sowing of the seed until the point of ingestion of a food by the consumer. Mycotoxins may develop prior to harvest or through inadequate storage. Most mycotoxins are inherently stable natural chemicals but cleaning, milling and different methods of processing can change their concentrations. Legislation is necessary to protect the consumer so it is important to consider, among other things, the relationship between concentrations of mycotoxins in the raw grains and those in the product purchased by the consumer, especially where different limits are specified at successive stages in manufacture. Recent studies of the fate of fusarium mycotoxins in the cereal food chain carried out alongside industry in the UK have examined changes in the concentrations of deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin and zearalenone in wheat, maize and oats and the fumonisin mycotoxins in maize at key stages in the cereal chain. For example, fumonisin concentrations in maize grits after milling were reduced by about 75% compared with the raw maize, but remained similar to the maize in the flour and were increased (*3 to *5) in the bran and meal. Maize flour and grits were then processed into a range of food products such as breakfast cereals, cornflakes, extruded snack products and tortillas and the changes in concentrations were established. Simple extrusion of flour or grits reduced fumonisins by a further 30-70% depending on the process. Deoxynivalenol and zearalenone were found to be more stable than fumonisins during most processes.