• Authors:
    • Ellert, B. H.
    • Janzen, H. H.
    • Carefoot, J. M.
    • Chang, C.
    • Hao, X.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 60
  • Issue: 1
  • Year: 2001
  • Summary: Nitrous oxide (N2O) emission from farmland is a concern for both environmental quality and agricultural productivity. Field experiments were conducted in 1996-1997 to assess soil N2O emissions as affected by timing of N fertilizer application and straw/tillage practices for crop production under irrigation in southern Alberta. The crops were soft wheat (Triticum aestivum L.) in 1996 and canola (Brassica napus L.) in 1997. Nitrous oxide flux from soil was measured using a vented chamber technique and calculated from the increase in concentration with time. Nitrous oxide fluxes for all treatments varied greatly during the year, with the greatest fluxes occurring in association with freeze-thaw events during March and April. Emissions were greater when N fertilizer (100 kg N ha-1) was applied in the fall compared to spring application. Straw removal at harvest in the fall increased N2O emissions when N fertilizer was applied in the fall, but decreased emissions when no fertilizer was applied. Fall plowing also increased N2O emissions compared to spring plowing or direct seeding. The study showed that N2O emissions may be minimized by applying N fertilizer in spring, retaining straw, and incorporating it in spring. The estimates of regional N2O emissions based on a fixed proportion of applied N may be tenuous since N2O emission varied widely depending on straw and fertilizer management practices.
  • Authors:
    • Williams, S.
    • Schuler, J.
    • Killian, K.
    • Kautza, T.
    • Elliott, T.
    • Easter, M.
    • Cipra, J.
    • Bluhm, G.
    • Paustian, K.
    • Brenner, J.
  • Year: 2001
  • Summary: Land managers have long known the importance of soil organic matter in maintaining the productivity and sustainability of agricultural land. More recently, interest has developed in the potential for using agricultural soils to sequester C and mitigate increasing atmospheric carbon- dioxide by adopting practices that increase standing stocks of carbon in soil organic matter and vegetation. Practices that increase the amount of CO2 taken up by plants (through photosynthesis), which then enter the soil as plant residues, tend to increase soil C stocks. Likewise, management practices that reduce the rate of decay or turnover of organic matter in soils will also tend to increase carbon stocks.
  • Authors:
    • Blomert, B.
    • Liang, B. C.
    • Selles, F.
    • Zentner, R. P.
    • Campbell, C. A.
  • Source: Canadian Journal of Soil Science
  • Volume: 81
  • Issue: 4
  • Year: 2001
  • Summary: Soil organic C (SOC) is readily influenced by crop management practices, such as summerfallowing. On the Canadian prairies, the area summerfallowed has decreased significantly in recent years. Our objectives were to determine the influence of fallow frequency on the rate of change in SOC in an Orthic Brown Chernozem, and to test the effectiveness of an empirical equation developed in an earlier study for estimating SOC changes in these rotations over 33-yr period. The rotations, which were initiated in 1967, all received adequate N and P fertilizers. They were (i) fallow-spring wheat (Triticum aestivum L.) (F-W), F-W-W, F-W-W-W-W-W and W-lentil (Lens culinaris L.) (W-Lent). Soil organic C was measured in the 0- to 15-cm and 15- to 30-cm depths in 1976, 1981, 1984, 1990, 1993, 1996 and 1999. No measurements of SOC were made in 1967; we estimated SOC starting values to be 30.5 Mg ha-1 in the 0- to 15-cm depth. In the period 1967 to 1990, when growing season precipitation was near normal for this semiarid region, SOC in the four rotations approached a steady state. However, a decade of much more favourable growing season precipitation in the 1990s increased C inputs, which resulted in a marked increase in SOC in the treatments. The empirical equation suggests, and the F-W and W-Lent rotations appear to confirm, that these rotations are approaching a new steady state at a higher level of SOC, reflecting the decade of favourable precipitation. Measured SOC levels were quite variable, emphasizing the difficulty of relying on measurements made over short time frames (e.g., 5-6yr) when quantifying SOC changes. The equation effectively simulated the trends in SOC changes in all rotations, but consistently underestimated SOC levels in the W-Lent rotation by about 2 Mg ha-1. Estimates of difference in SOC between treatments were generally similar whether expressed on a mass/fixed depth or a mass/equivalent depth basis. Based on the estimates derived by the empirical equation, we estimated rates of SOC sequestration during the 1967-1990 period to be 0.03 Mg ha-1 yr-1 for F-W, 0.10 Mg ha-1 yr-1 for F-W-W, and 0.15 Mg ha-1 yr-1 for W-Lent. If we include the decade of more favourable precipitation (1967-1999), the rates were between 0.05 Mg ha-1 yr-1 for F-W and 0.20 Mg ha-1 yr-1 for W-Lent. These values are much higher than those estimated by others using the CENTURY model. We concluded that (i) simple models, such as that used in this study, are very useful for estimating management effects on SOC changes, and (ii) we must be cautious in extrapolating C sequestration estimates based on data from short-term experiments because future weather conditions are not easily predicted and weather can have an important impact on C sequestration.
  • Authors:
    • McRae, F. J.
  • Source: Winter crop variety sowing guide 2001
  • Year: 2001
  • Summary: This guide contains information that aims to assist farmers in New South Wales, Australia, to make better cropping decisions and higher profits as well as increased productivity from the resources invested, along with total sustainability of the farm. Variety guides are given for the following winter crops: wheat (including durum wheat), barley, oats, triticale, cereal rye, grazing cereals, canola [rape], chickpea, faba bean, field pea and lupin. An evaluation of varietal characteristics, reactions to diseases, crop injury and profitable marketing of these winter crops is discussed. Weed control is detailed for some crops. Industry information on wheat receival sites and the different wheat authorities is presented. Options for the control of insect pests of stored grain, the location of various district agronomists, and a list of cereal seed dressings for the control of seed-borne diseases are provided. Hints on volumetric grain weights, typical bulk densities and the angles of repose of some grains is mentioned.
  • Authors:
    • Tonkin, C. J.
    • Dellow, J. J.
    • Mullen, C. L.
  • Source: Weed control in winter crops 2001
  • Year: 2001
  • Summary: This handbook is a guide to chemical weed control in fallows, wheat, barley, oats, rye, triticale, canola [rape], safflower, lentil, linseed, lupin, chickpea, faba bean and field pea. Information are also presented on the optimum rate, timing and method of herbicide application, use of adjuvants, surfactants and oils, and herbicide resistance.
  • Authors:
    • Powell, C.
  • Source: New South Wales Department of Agriculture
  • Year: 2001
  • Summary: Variety trials conducted in New South Wales, Australia in 2000 are reported for winter crops of barley, canola [rape], chickpeas, faba beans, field peas, lentils, lupins ( Lupinus albus and L. angustifolius), mixed cereals, oats, triticale and wheat.
  • Authors:
    • Scott, F.
  • Source: Farm Budget Handbook, Northern NSW - Winter Crops 2001
  • Year: 2001
  • Summary: This handbook presents gross margin budgets for annual winter crops and pasture establishment to assist landholders in northern New South Wales, Australia, plan for the 2001 winter cropping season.
  • Authors:
    • Roggenstein, V.
    • Fischbeck, G.
    • Dennert, J.
  • Source: Getreide Magazin
  • Issue: 3
  • Year: 2001
  • Summary: A study was initiated in 1980 in Germany on a soil with 4% humus and 18.2 mg P 20 5/100 g soil and 35.7 mg K 20/100 g soil. Crops included winter wheat, barley, rye, oats, rape, and maize. Annual soil analyses showed an unexpectedly large variation following inputs of up to 60 kg P/ha and 80 kg K/ha. The difference in P and K supply between fertilized and unfertilized plots was around 20%. However, the effect on yields was less than might have been expected. Non-application of P did not influence yield, while non-application of K resulted in 5% decrease (despite high K availability). No direct relationship was found between soil analysis and yields.
  • Authors:
    • Faour, K.
  • Source: Farm Budget Handbook, Southern NSW - Irrigated Winter Crops 2001
  • Year: 2001
  • Summary: This handbook presents gross margin budgets for irrigated winter crops and pasture establishment to assist landholders in the Murrumbidgee and Murray valleys (southern New South Wales, Australia) plan for the 2001 winter cropping season.
  • Authors:
    • UK, National Institute of Agricultural Botany
  • Source: Pocket guide to varieties of cereals, oilseeds and pulses for Spring 2002
  • Year: 2001
  • Summary: This edition presents information on the spring sown varieties of wheat, barley, oats, oilseed rape, 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. General information is also given on minor spring sown oil crops.