• Authors:
    • Sukhochev, V. N.
    • Gurin, A. G.
  • Source: Sadovodstvo i Vinogradarstvo
  • Issue: 2
  • Year: 2003
  • Summary: In research during 1997-2000 at the All-Russian Institute of Fruit Crop Breeding in Orel province, Russia, the use of field crops sown between strawberry rows was investigated as a means of suppressing weed growth. Oats, barley, rape and mustard were sown between rows of strawberry cv. Red Gauntlet; the sowing date was manipulated so that the field crops would be cut down after strawberry harvest but before they could set seed. In terms of the number of plants of the major weed species present at the end of vegetative growth, there were 122 plants per linear m in the untreated control, but only 37 in the barley, 48 in the oats, 53 in the mustard and 60 in the rape treatments. The cereals were better at suppressing weeds because they were sown earlier than the crucifers. In terms of annual strawberry fruit yield, the average for the 4 years of the trial was 8.07 t/ha in the control but higher with the weed suppressing crops: 8.18, 8.49, 8.62 and 8.66 for the rape, mustard, oats and barley treatments, respectively.
  • Authors:
    • Felton, W.
    • Haigh, B.
  • Source: Update of research in progress at the Tamworth Agricultural Institute 2002
  • Year: 2003
  • Summary: Crop growth rate and weed competition were studied in New South Wales, Australia during 2002 using reflectance sensors. Seeds of wheat cv. Sunstate, chickpea cv. Howzat, faba bean cv. Fiord and rape cv. Oscar were sown at 40, 70, 100 and 3 kg/ha, respectively. Two reflectance sensors mounted on a small tractor were used to collect data across each plot every two weeks (45-129 days after sowing). Wheat recorded the greatest biomass, yield and water consumption, whereas chickpea recorded the highest harvest index and lowest water consumption. The rate of crop development was greatest in wheat and lowest in chickpea. The number of days required to produce 1000 kg/ha of shoot dry matter was 92, 100, 102 and 11 days after sowing for wheat, faba bean, rape and chickpea, respectively. Reflectance measurements were also used to evaluate the potential of wheat, triticale and barley as 'mimic weeds' against wild oat [ Avena fatua] in chickpea. Reflectance estimates were made at 51, 62, 84, 100 and 120 days after sowing. The 'mimic weeds' established faster than wild oat. The density of wild oat was lower than that of the mimic weeds, although none of the weeds achieved the target density of 81 weeds/m 2. The similar linear relationships with regard to the effects of weed biomass on crop yield for wild oat and 'mimic weeds' indicated that the latter can be used in weed studies instead of the actual weed. At low densities, wheat and barley were the most competitive. Triticale and wild oat exhibited similar competitive ability.
  • Authors:
    • Crawford, M.
    • Ransom, K.
    • Hirth, J.
    • Harris, R.
    • Naji, R.
  • Source: Solutions for a better environment: Proceedings of the 11th Australian Agronomy Conference, Geelong, Victoria, Australia, 2-6 February 2003
  • Year: 2003
  • Summary: Companion cropping (also known as intercropping) of lucerne involves sowing an annual crop into an existing lucerne stand. A sample of eight farmers from north central Victoria, Australia, who currently companion crop, were interviewed to document the impact of this practice on grain production, and to determine why and how they used this approach in their farming system. All eight farmers companion cropped lucerne to produce grain for either human or livestock consumption. Wheat, barley, oat and triticale were most commonly sown into lucerne stands, with rape less frequently companion cropped. Most companion-cropped stands of lucerne were either winter-active or highly winter-active cultivars and most had densities of 10-30 plants/m 2. They were commonly 9-12 months old, although some stands up to 10 years old were successfully companion cropped. Sowing rates of the annual crop were generally greater than those used in conventional monoculture cropping, and most farmers sowed diagonally across existing lucerne rows. Most interviewed farmers adopted companion cropping because of perceived better economic returns from cropping rather than grazing their second-year stands of lucerne, which then became more persistent and productive stands for future grazing. Farmers who companion cropped into mature stands aimed to maintain year-round plant transpiration to minimize the impact of their cropping practices on local groundwater systems, through a better hydrologic balance between the rainfall and their vegetation. Decreased grain yields from companion-cropped crops were common, and were estimated to be 10 to 80% of those obtained in the absence of lucerne. The magnitude of the yield decreases appeared to be most strongly influenced by seasonal conditions. The use of herbicides for in-crop lucerne suppression was perceived to enhance grain quality by slowing lucerne growth over the late winter-spring period, thereby reducing lucerne seed and herbage contamination at harvest. As seasonal and soil water conditions critically influenced the success of herbicide applications, specialist advice was often sought.
  • Authors:
    • UK, National Institute of Agricultural Botany (NIAB)
  • Source: Pocket guide to varieties of cereals, oilseeds & pulses for autumn 2003
  • Year: 2003
  • Summary: This edition presents information on the autumn sown varieties of wheat, barley, oats, triticale, rye, durum wheat, oilseed rape, linseed, peas and beans. Individual information on each variety is given, including variety notes, yield performance, relative ranking position in different environments and a summary of the important character ratings from the Recommended Lists.
  • Authors:
    • Abramov, A. F.
  • Source: Kormoproizvodstvo
  • Issue: 7
  • Year: 2003
  • Summary: On the basis of biochemical analyses, the types of fodder and the fodder plants that can be produced under the severe environmental conditions of Yakutia in north-east Russia are discussed. Suitable species include oats, barley, rye, sunflower, rape, peas, lucerne and sweet clover [ Melilotus], while the fodders that can be produced include silage, haylage, meal produced from the green matter of cereals and grasses, combined fodders and fodder mixtures.
  • Authors:
    • Fielding, D. J.
    • Begna, S. H.
  • Source: Journal of Economic Entomology
  • Volume: 96
  • Issue: 4
  • Year: 2003
  • Summary: We characterized the type and extent of grasshopper injury to above- and below-ground plant parts for four crops, i.e. barley ( Hordeum vulgare), oats ( Avena sativa), wheat ( Triticum aestivum), and canola [turnip rape] ( Brassica campestris [ B. campestris var. oleifera]), commonly grown, or with potential to grow, in central Alaska, USA. Cages were placed on 48 pots containing plants in second to third leaf stages and stocked with 0, 2, 4, and 6 first-instar Melanoplus sanguinipes pot -1. Plants were harvested 22 days after planting. Stem growth of barley and oats was not affected except at the highest grasshopper treatment. In rape, stem biomass was reduced at the medium and high grasshopper treatments, when most of the leaves had been consumed. The highest grasshopper treatment reduced leaf area in barley and oats by ~55%, and caused a significant reduction in dry weight of leaves, stems, and roots (41-72%). Wheat and canola plants were smaller than barley and oats across all treatments and, at the highest grasshopper density, above-ground portions of wheat and canola were completely destroyed. Length and surface area of roots of barley and oats were reduced by 20-28% again at the highest grasshopper density, whereas the reduction for wheat and canola ranged from 50 to 90%. There was little or no difference among all grasshopper densities for C:N ratio in leaf and stem tissues of all crops. The results suggest that wheat and canola are more susceptible than barley and oats and that densities ≥2 pot -1 (~≥50 m -2) of even very small grasshoppers could cause significant damage in small-grain and oilseed crop production.
  • Authors:
    • Marland, G.
    • West, T. O.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 91
  • Issue: 1-3
  • Year: 2002
  • Summary: The atmospheric CO2 concentration is increasing, due primarily to fossil-fuel combustion and deforestation. Sequestering atmospheric C in agricultural soils is being advocated as a possibility to partially offset fossil-fuel emissions. Sequestering C in agriculture requires a change in management practices, i.e. efficient use of pesticides, irrigation, and farm machinery. The C emissions associated with a change in practices have not traditionally been incorporated comprehensively into C sequestration analyses. A full C cycle analysis has been completed for agricultural inputs, resulting in estimates of net C flux for three crop types across three tillage intensities. The full C cycle analysis includes estimates of energy use and C emissions for primary fuels, electricity, fertilizers, lime, pesticides, irrigation, seed production, and farm machinery. Total C emissions values were used in conjunction with C sequestration estimates to model net C flux to the atmosphere over time. Based on US average crop inputs, no-till emitted less CO2 from agricultural operations than did conventional tillage, with 137 and 168 kg C ha(-1) per year, respectively. Changing from conventional tillage to no-till is therefore estimated to both enhance C sequestration and decrease CO2 emissions. While the enhanced C sequestration will continue for a finite time, the reduction in net CO2 flux to the atmosphere, caused by the reduced fossil-fuel use, can continue indefinitely, as long as the alternative practice is continued. Estimates of net C flux, which are based on US average inputs, will vary across crop type and different climate regimes. The C coefficients calculated for agricultural inputs can be used to estimate C emissions and net C flux on a site-specific basis. Published by Elsevier Science B.V.
  • Authors:
    • Ulrich, D.
    • Brandt, S. A.
    • Malhi, S. S.
    • Lemke, R.
    • Gill, K. S.
  • Source: Journal of Plant Nutrition
  • Volume: 25
  • Issue: 11
  • Year: 2002
  • Summary: Cropping systems can influence the accumulation and distribution of plant nutrients in the soil profile, which can affect their utilization efficiency by crops and pollution potential in the environment. A field experiment was conducted on a Dark Brown loam soil at Scott, Saskatchewan, Canada to assess the effects of input level, cropping diversity and crop phase on the accumulation and distribution of nitrate-nitrogen (N) and extractable phosphorus (P) in the soil profile at the end of 1995 to 2000 growing seasons. The 54 treatments were combinations of three input levels (organic-ORG, reduced-RED and high-HIGH), three cropping diversities (low diversity-LOW, diversified annual grains-DAG, and diversified annual and perennials-DAP), and six crop phases chosen from fallow (tillage-fallow or chemfallow), green manure [lentil-Lens culinaris Medicus or sweet clover-Melilotus officinalis (L.) Lam], spring wheat (Triticum aestivum L.), canola (Brassica napus L. and Brassica rapa L.), fall rye (Secale cereale L.), field pea (Pisum sativum L.), spring barley (Hordeum vulgare L.), flax (Linum usitatissimum L.), oats (Avena sativa L.), and bromegrass (Bromus inermis Leyss), alfalfa (Medicago sativa Leyss) mixture hay. Soil was sampled from the 0-15, 15-30, 30-60, and 60-90cm depths in each crop phase from 1995 to 2000, with additional depths 90-120, 120-150, 150-180, 180-210, and 210-240cm taken from the wheat phase in 2000. In general, there were greater amounts of nitrate-N with HIGH input compared to ORG or BID inputs, especially under LOW diversity. The nitrate-N in various soil depths suggested some downward movement of nitrate-N to the deeper soil depths when HIGH input was compared to ORG input. In LOW cropping diversity, green manure or fallow usually had more nitrate-N in soil than other crop phases. In DAG and DAP cropping diversities, nitrate-N varied with crops and on average it had maximum concentration after wheat or canola in DAG and after hay followed closely by wheat in DAP. The ORG input level had greater nitrate-N than RED or HIGH inputs in some instances, most likely due to relatively low extractable P in soil for optimum crop growth under ORG input. Extractable P in the 0-15 and 15-30 cm soil depths tended to be greater under HIGH or RED inputs compared to the ORG input level in many cases. In summary there was no consistent effect of cropping diversity on extractable P in soil under ORG input, but LOW diversity tended to show more extractable 13 compared to DAG and DAP diversities in some cases of RED and HIGH inputs. The green manure/fallow, HIGH input and LOW diversity treatments tended to result in higher nitrate-N and extractable P levels compared to the corresponding treatments, and the effects were more pronounced on nitrate-N than extractable P and in shallow compared to deeper soil layers.
  • Authors:
    • Chanasyk, D. S.
    • Mathison, M. N.
    • Naeth, M. A.
  • Source: Canadian Journal of Soil Science
  • Volume: 82
  • Issue: 2
  • Year: 2002
  • Summary: The longevity of deep ripping effects on Solonetzic soils was investigated at 11 field sites in east-central Alberta after a period of 15 to 20 yr. Select soil properties and crop yield of deep-ripped and non-ripped control plots were analyzed. Dryland yield data of wheat, barley, oats and canola were assessed for 10 of the 11 sites over a 16-yr time period. Select soil properties were analyzed once in 1998 with penetration resistance (PR) evaluated again in 1999. A significant difference in penetration resistance was found between the deep ripped versus control treatments ( P≤0.05). There were no significant treatment differences for soil texture, bulk density (Db), pH, electrical conductivity (EC) or sodium adsorption ratio (SAR). A significant yield difference between the deep ripping and control treatments (for all crop species) was found for 6 of 10 sites ( P≤0.10), with all sites having an increase in mean yield for the majority of years evaluated. Generally, sites in the drier ecoregions had smaller yield increases than those in the wetter ones. Hence some beneficial effects from deep ripping remain for a long time period.
  • Authors:
    • Michalski, T.
    • Bartos, M.
  • Source: Progress in Plant Protection
  • Volume: 42
  • Issue: 2
  • Year: 2002
  • Summary: Experiments were conducted during 1996-99 in Poland to study the effect of sowing density on barley, oat, wheat and triticale weed infestation. The cereals were sown in 4 densities, starting from 400 grains of barley and 650 grains of the other species (100%) and consequently reduced to 80, 60 and 40%. Number and weight of weeds in each year was seriously diverse. Weed infestation was the smallest (mean 27 weeds/m 2) at high sowing density and increased with a decrease in sowing density, reaching 88 weeds at the smallest density of cereals. The reduction of sowing density by 20% increased weed density 40-50%. The most frequent weeds were Setaria viridis and cultivated rape ( Brassica napus var. oleifera).