• Authors:
    • Jalli, M.
    • Huusela-Veistola, E.
    • Hannukkala, A. O.
    • Hakala, K.
    • Peltonen-Sainio, P.
  • Source: Agricultural and Food Science
  • Volume: 20
  • Issue: 1
  • Year: 2011
  • Summary: A longer growing season and higher accumulated effective temperature sum (ETS) will improve crop production potential in Finland. The production potential of new or at present underutilised crops (e. g. maize (Zea mays L.), oilseed rape (Brassica napus L.), lucerne (Medicago sativa L.)) will improve and it will be possible to grow more productive varieties of the currently grown crops (spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.)). Also cultivation of autumn sown crops could increase if winters become milder and shorter, promoting overwintering success. Climatic conditions may on the other hand become restrictive in many ways. For example, early season droughts could intensify because of higher temperatures and consequent higher evaporation rates. Current low winter temperatures and short growing season help restrict the development and spread of pests and pathogens, but this could change in the future. Longer growing seasons, warmer autumns and milder winters may initiate new problems with higher occurrences of weeds, pests and pathogens, including new types of viruses and virus vectors. Anoxia of overwintering crops caused by ice encasement, and physical damage caused by freezing and melting of water over the fields may also increase. In this study we identify the most likely changes in crop species and varieties in Finland and the pest and pathogen species that are most likely to create production problems as a result of climate change during this century.
  • Authors:
    • Rydberg, T.
    • Keller, T.
    • Arvidsson, J.
    • Håkansson, I.
  • Source: Acta Agriculturae Scandinavica, Section B - Soil & Plant Science
  • Volume: 61
  • Issue: 5
  • Year: 2011
  • Summary: Rapid and uniform crop establishment is a prerequisite for efficient crop production and minimal environmental impact. Experiments were carried out in shallow plastic boxes placed directly on the ground in the field for studies of the effects of seedbed properties on emergence of various crops. This paper presents an analysis of the time required for germination and emergence under near-optimal seedbed conditions. The crops studied were barley, oats, wheat, pea, rape seed, white mustard, sugar beet, red clover and timothy. The time required for germination generally increased with size of the seeds, presumably because larger seeds needed more water to initiate germination. This applied both when comparing different crops and different seed sizes of the same crop. However, considerable differences occurred between seed lots of the same crop and there were greater differences between seed lots of the same crop than between the three small grain crops studied. Growth rate of the seedlings generally increased with seed size, presumably because of increased energy content in the seed. Consequently, the most rapid emergence was obtained from small seeds at shallow sowing and from large seeds at deep sowing. The crops studied had a minimum temperature for germination and seedling growth close to 0 degrees C. Under optimal seedbed conditions, thermal time required for 50% germination of barley was typically about 65 degrees C days over this base temperature and for seedling growth about 6 degrees C days cm(-1). From 4 cm sowing depth, about 80 degrees C days were required for emergence but with considerable variations between seed lots. For rape seed or white mustard about 40 degrees C days were required for germination and about 8 degrees C days cm(-1) for the seedling growth.
  • Authors:
    • Shostak, Z. A.
  • Source: Russian Meteorology and Hydrology
  • Volume: 36
  • Issue: 12
  • Year: 2011
  • Summary: The methods are presented of agrometeorological forecasting of winter and spring grain crops for the district, all types of farm units, and field taking account of the regional crop forecast, weather conditions, cereal cropping technologies, and soil cultivation level. The additional yields of winter and spring wheat and spring barley and oat are developed depending on the soil cultivation level, summertime soil moistening, and doses of mineral fertilizers. The method tested on the basis of independent data demonstrated that the accuracy of such forecasts is 83-99% for the fields with intensive cultivation technology and 80% for the farm units.
  • Authors:
    • Schoenau, G.
    • Tabil, L.
    • Adapa, P.
  • Source: Biomass and Bioenergy
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: Grinding experiments were conducted on non-treated and steam exploded barley, canola, oat and wheat straw using a forage chopper and a hammer mill (screen sizes of 30, 6.4, 3.2 and 1.6 mm) to determine specific energy requirements, and geometric mean particle size and distribution of ground material. The bulk density of non-treated biomass was significantly higher than bulk density of steam exploded agricultural biomass. For non-treated agricultural straw, the particle density of canola and oat straw significantly increased with a decrease in hammer mill screen size from 30 to 1.6 mm. The particle density of steam exploded barley and oat straw was significantly higher than non-treated straw, except for barley at 6.4 mm hammer mill screen size. The particle density of steam exploded canola straw was not statistically different from non-treated straw. The chopper consumed highest (3.15 +/- 0.09 kWh t(-1)) and lowest (1.96 +/- 0.33 kWh t(-1)) specific energy to chop barley and canola straw, respectively. The highest and lowest specific energy was consumed by wheat (42.57 +/- 2.04 kWh t(-1)) at 1.6 mm and canola (1.46 +/- 0.30 kWh t(-1)) straws ground using 30 mm hammer mill screen size, respectively. For steam exploded agricultural biomass, the highest and lowest specific energy was consumed by oat (33.18 +/- 3.10 kWh t(-1)) at 1.6 mm and canola (2.69 +/- 0.26 kWh t(-1)) straws ground using 6.4 mm hammer mill screen size, respectively. Specific energy required by hammer mill to grind non-treated and steam exploded barley, canola, oat and wheat straw showed a negative power correlation with hammer mill screen sizes. (C) 2010 Elsevier Ltd. All rights reserved.
  • Authors:
    • Costa Crusciol, C. A.
    • Calonego, J. C.
    • Amaral Castro, G. S.
  • Source: Pesquisa Agropecuária Brasileira
  • Volume: 46
  • Issue: 12
  • Year: 2011
  • Summary: The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight replicates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha(-1) of dolomitic lime (ECC = 90%) or 4.1 Mg ha(-1) of calcium-magnesium silicate (ECC = 80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.
  • Authors:
    • Risede, J.-M.
    • Foster, J.
    • Rhodes, R.
    • Berry, S. D.
    • van Antwerpen, R.
  • Source: International Journal of Pest Management
  • Volume: 57
  • Issue: 4
  • Year: 2011
  • Summary: Plant-parasitic nematodes cause significant yield losses to sugarcane crops in South Africa. The currently available chemicals for nematode control are both expensive and potentially detrimental to the environment. Various alternative crops have been reported to reduce the numbers of plant-parasitic nematodes. Mindful of this, we evaluated 27 cover crops in pot trials to assess their host status to important plant-parasitic nematodes of sugarcane. All of the crops tested in pots hosted significantly lower numbers of Pratylenchus than did sugarcane. Crops such as cowpeas, tomato and grazing vetch were good hosts for Meloidogyne and would not be good choices as part of a sugarcane rotation system in heavily-infested soils. Conversely, crops such as oats, wheat, forage peanuts and marigolds reduced numbers of Meloidogyne. Velvet beans increased the abundance of Helicotylenchus, a beneficial nematode genus. A field trial was also conducted to study the effect of different cover cropping sequences. Our results show that changes in nematode communities occurred within three months of growing these crops and often remained low for the duration (the remaining 15 months) of the crops' growth. Nematodes such as Pratylenchus and Tylenchorhynchus were significantly lowered and remained so for the duration of the trial.
  • Authors:
    • Mulvaney, M. J.
    • Wood, C. W.
    • Kemble, J. M.
    • Balkcom, K. S.
    • Shannon, D. A.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 5
  • Year: 2010
  • Summary: A combination of high biomass cover crops with organic mulches may be an option for no-till vegetable production, but information on mineralization rates from these residues is lacking. The objective of this study was to assess nutrient release rates and persistence from mimosa ( Albizia julibrissin Durazz.), lespedeza [ Lespedeza cuneata (Dum. Cours.) G. Don], oat ( Avena sativa L.) straw, and soybean [ Glycine max (L.) Merr.] residues under conventional and conservation tillage. The experiment was conducted in Tallassee, AL using litterbag methodology in a split-plot design (main plots: two tillage systems; subplots: four residue types). Comparison of rate constants showed that labile portions of residues was more affected by tillage than recalcitrant portions. In spring, mimosa residue contained 78 kg N ha -1 when buried the previous fall, compared to 123 kg N ha -1 when surface placed; soybean residue showed similar results (39 vs. 72 kg N ha -1, respectively). Results were similar for lespedeza (72 vs. 101 kg N ha -1, respectively), but not for oat straw (24 vs. 26 kg N ha -1, respectively). After 1 yr, surface placed mimosa residue mineralized 33% of initial N compared to 71% when buried, while surface placed lespedeza mineralized 36% of initial N compared to 64% when buried. Soybean residue mineralized N quickly regardless of placement (73 vs. 87%, respectively). This study demonstrates that cut-and-carry mulches may be used under conservation tillage for the enhancement of soil organic matter (SOM), soil organic carbon (SOC), and soil N status.
  • Authors:
    • Balesdent, J.
    • Munoz, C.
    • Vidal, I.
    • Zagal, E.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world
  • Year: 2010
  • Summary: Sustainable agriculture should maintain soil organic carbon to prevent soil degradation and erosion, but soil C management still requires basic data on soil C dynamics under many climates, soil types and land uses. We applied a simple field method for the measurement of soil carbon dynamics, based on the natural 13C labelling technique of carbon inputs. The method implies the addition of locally produced maize material into the soil with C3 crops, in a simple, light and cost-effective design, and the kinetic analysis of soil 13C/ 12C. In Chile the approach was applied on a nine years fertility experiment with no till conditions sustaining a wheat-oat rotation, and followed thereafter for 5 years. The experimental site is located in the Andes pre-mountain (36degrees55′S, 71degrees53′O). The soil is of volcanic origin (medial, amorphic, mesic, Typic Haploxerands) and the crop rotation wheat-oat. The labeling technique showed that a very low amount (about 1 t ha -1) was incorporated to the soil (new C) during the time-period of the experiment (4 years). The ratio of remaining C/ added C after 4 years was very low (0.03) suggesting that the high carbon content of the soil can therefore be considered as due to a large amount of passive carbon, or to ancient carbon inputs, that have saturated the sorption capacity.
  • Authors:
    • Yogo, Y.
    • Asai, M.
  • Source: Journal of Weed Science and Technology
  • Volume: 55
  • Issue: 3
  • Year: 2010
  • Summary: Paraquat is an herbicide that inhibits germination and seedling growth of grasses, including wild oat ( Avena fatua L.), a problematic weed in winter cereals. Outdoor pot experiments were conducted to determine the influence of paraquat on wild oat seedling emergence to evaluate the efficacy of this herbicide as a tool for an integrated management system. A diquat+paraquat liquid formulation (7.0% diquat dibromide and 5.0% paraquat dichloride) was sprayed at a rate of 1,000 ml/10 a directly onto wild oat seeds placed on the soil surface, and the soil was not disturbed during the following year. Fewer viable wild oat seeds were recovered from the diquat+paraquat treatment relative to a glyphosate ammonium salt (41.0%, 500 ml/10 a) treatment. A treatment of diquat+paraquat greater than 3,000 ml/10 a markedly reduced wild oat seedling emergence if the seeds were incorporated into the soil soon after the application. However, when the wild oat seeds were covered with chopped straw, no suppression of emergence could be detected with diquat+paraquat application even at a rate of 4.6 times the recommended dose. Increasing the dilution water volume also decreased the effectiveness of emergence suppression. Our results suggest that diquat+paraquat spray following wheat harvest would not be effective for reducing wild oat germination and seedling emergence in the summer.
  • Authors:
    • Boykin, D.
    • Balkcom, K.
    • Arriaga, F.
    • Balkcom, K.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 2
  • Year: 2010
  • Summary: Increased production costs and potential benefits of maintaining surface residue has renewed interest in conservation tillage systems for peanut ( Arachis hypogaea L.) production. We determined surface residue cover from rye ( Secale cereale L.) or oat ( Avena sativa L.) cover crops after two strip tillage systems (narrow vs. wide) and planting operations with different row configurations (single vs. twin). We also compared plant populations, yields, and total sound mature kernels for three peanut cultivars ('ANorden', 'AP-3', and 'Georgia-02C') across each treatment combination. Seven site-years were examined across similar soil types in Alabama and northern Florida during the 2004 to 2006 growing seasons. The highest surface residue counts were for the narrow tillage system planted in single rows. Final plant stands were influenced by an interaction between cultivar and row configuration, with 'ANorden' planted in single rows below recommended rates. Peanut yields were affected by strip tillage system and row configuration, but differences among cultivars were also observed. Twin-row peanut yields were 5% greater than single-row peanut yields in the narrow strip tillage system but were similar across strip tillage systems. Cultivars 'AP-3' and 'Georgia-02C' yielded 20% higher than 'ANorden'. Total sound mature kernels were only affected by peanut cultivar, with the cultivar 'Georgia-02C' producing the highest-quality peanut, followed by 'ANorden' and 'AP-3'. These results indicate that growers interested in using twin rows for peanut production can also take advantage of a narrow strip tillage system that maximizes surface residue coverage and subsequent benefits.