• Authors:
    • Grant, C.
    • Khakbazan, M.
    • Mohr, R.
  • Source: López-Francos A. (comp.), López-Francos A. (collab.). Economics of drought and drought preparedness in a climate change context. Zaragoza : CIHEAM / FAO / ICARDA / GDAR / CEIGRAM / MARM, 2010 (Options Méditerranéennes : Série A. Séminaires Méditerranéens;
  • Issue: 95
  • Year: 2010
  • Summary: The objective of this paper was to study the impact of drought and adaptation measures on the economics of production for some major crops grown in Western Canada. Crop yields, yield variability, and crop losses were analyzed to quantify drought impacts and statistical models were developed to estimate the relationship between yield and growing season precipitation for wheat, canola, oats, and barley. The linear and quadratic precipitation terms were found to have the correct sign and to be significantly related to yield (p
  • Authors:
    • Honeycutt, C. W.
    • Griffin, T. S.
    • Larkin, R. P.
  • Source: Plant Disease
  • Volume: 94
  • Issue: 12
  • Year: 2010
  • Summary: Seven different 2-year rotations, consisting of barley/clover, canola, green bean, millet/rapeseed, soybean, sweet corn, and potato, all followed by potato, were assessed over 10 years (1997-2006) in a long-term cropping system trial for their effects on the development of soilborne potato diseases, tuber yield, and soil microbial communities. These same rotations were also assessed with and without the addition of a fall cover crop of no-tilled winter rye (except for barley/clover, for which underseeded ryegrass was substituted for clover) over a 4-year period. Canola and rapeseed rotations consistently reduced the severity of Rhizoctonia canker, black scurf, and common scab (18 to 38% reduction), and canola rotations resulted in higher tuber yields than continuous potato or barley/clover (6.8 to 8.2% higher). Addition of the winter rye cover crop further reduced black scurf and common scab (average 12.5 and 7.2% reduction, respectively) across all rotations. The combined effect of a canola or rapeseed rotation and winter rye cover crop reduced disease severity by 35 to 41% for black scurf and 20 to 33% for common scab relative to continuous potato with no cover crop. Verticillium wilt became a prominent disease problem only after four full rotation cycles, with high disease levels in all plots; however, incidence was lowest in barley rotations. Barley/clover and rapeseed rotations resulted in the highest soil bacterial populations and microbial activity, and all rotations had distinct effects on soil microbial community characteristics. Addition of a cover crop also resulted in increases in bacterial populations and microbial activity and had significant effects on soil microbial characteristics, in addition to slightly improving tuber yield (4% increase). Thus, in addition to positive effects in reducing erosion and improving soil quality, effective crop rotations in conjunction with planting cover crops can provide improved control of soilborne diseases. However, this study also demonstrated limitations with 2-year rotations in general, because all rotations resulted in increasing levels of common scab and Verticillium wilt over time.
  • Authors:
    • Marinov-Serafimov, P.
  • Source: Selskostopanska Nauka (Agricultural Science)
  • Volume: 43
  • Issue: 2
  • Year: 2010
  • Summary: The study was conducted during 2005-2007 at the experimental field of Experimental stations in soybeans - Pavlikeni without irrigated conditions in secondary leaching on black earth in order to establish the possibility of an alternative control against weeds in soybean ( Glycine max [L.] Merr.) using allelopathic-mulching crop-oats. Relations between the two plant species, soybean-barley were followed in two factors: Factor A - the quantity of oats in the rate of propagation rate: a 1 - (Control manual removal of weeds, soybean monoculture) a 2 - (Control without manual removal of weeds, soybean monoculture) a 3 - 12%; a 4 - 25% and a 5 - 50%. Factor B - duration of the development of soybeans to emergence (VE): b 1 - flowering (R 2), b 2 - pod formation (R 4) and b 3 - technical ripeness (R 8). It was found that the use of oats as allelopathic-mulching culture in soy reduces the rate of sowing weed infestans from 33.0 to 66.0% and the cumulative amount of fresh and dry biomass (from 12.0 to 68.0%) of the group of late spring weeds, a disproportionate amount of the increased propagation norm; Weed suppression resolution allelopathic-mulching culture agrophytocenosa study is the result of limiting the density of some dicotyledonous annual weeds Amaranthus ssp., Abutilon theophrasti Medik. and Chenopodium album (L.), despite being down compensation processes in population density of Convolvulus arvensis L. uniformity in distribution of (J) - from -4.2 to -10.2; species composition (S) of weed communities is from 4 to 8 species, but in terms of their diversity (H) - from -5.9 to -21.2; complex effect of weed infestants and extent of the propagation rules of oats have a negative impact on yield of soybeans - kg/ha from 25.3 to 63.0 percent, the height of soybean flour (RCI varies from 0.11 to 0.35) and formed on fresh and dry biomass (RCI is in the range of 0.44 to 0.83) on the soybean, which can be offset by the reduced level of weed infestans in soybean agrophytotsenosis.
  • Authors:
    • Brennan, J. P.
    • Murray, G. M.
  • Source: Australasian Plant Pathology
  • Volume: 39
  • Issue: 1
  • Year: 2010
  • Summary: The incidence, severity and yield loss caused by 40 pathogens associated with 41 diseases of barley were assessed from a survey of 15 barley pathologists covering the winter cereal growing areas of Australia. The survey provided data on the frequency of years that each pathogen developed to its maximum extent, the proportion of the crop then affected in each growing area, and the yield loss that resulted in the affected crops with and without current control measures. These data were combined with crop production and grain quality data to estimate the value of the losses aggregated to the Northern, Southern and Western production regions. Pathogens were estimated to cause a current average loss of $252 x 10(6)/year or 19.6% of the average annual value of the barley crop in the decade 1998-99 to 2007-08. Nationally, the three most important pathogens are Pyrenophora teres f. maculata, Blumeria graminis f. sp. hordei and Heterodera avenae with current average annual losses of $43 x 10(6), $39 x 10(6) and $26 x 10(6), respectively. If current controls were not used, losses would be far higher with potential average annual losses from the three most important pathogens, P. teres f. maculata, H. avenae and P. teres f. teres, being $192 x 10(6), $153 x 10(6) and $117 x 10(6), respectively. The average value of control practices exceeded $50 x 10(6)/year for nine pathogens. Cultural methods (rotation, field preparation) were the only controls used for 14 pathogens and contributed more than 50% of the control for a further 13 pathogens. Breeding and the use of resistant cultivars contributed more than 50% of control for five pathogens and pesticides for four pathogens. The relative importance of pathogens varied between regions and zones.
  • Authors:
    • Jauhiainen, L.
    • Peltonen-Sainio, P.
  • Source: Agricultural and Food Science
  • Volume: 19
  • Issue: 4
  • Year: 2010
  • Summary: The balance between applied and harvested nitrogen (yield removed nitrogen, YRN %) is a recognized indicator of the risk of N leaching. In this study we monitored the genetic improvements and environmental variability as well as differences among crop species (spring cereals and rapeseed) in YRN in order to characterize changes that have occurred and environmental constraints associated with reducing N leaching into the environment. MTT long-term multi-location field experiments for spring cereals (Hordeum vulgare L., Avena sativa L. and Triticum aestivum L.), turnip rape (Brassica rapa L.), and oilseed rape (B. napus L.) were conducted in 1988-2008, covering each crop's main production regions. Yield (kg ha(-1)) was recorded and grain/seed nitrogen content (N(grain), g kg(-1)) analyzed. Total yield N (N(yield), kg ha(-1)) was determined and YRN (%) was calculated as a ratio between applied and harvested N. A mixed model was used to separate genetic and environmental effects. Year and location had marked effects on YRN and N(yield). Average early and/or late season precipitation was often most advantageous for N(yield) in cereals, while in dry seasons N uptake is likely restricted and in rainy seasons N leaching is often severe. Elevated temperatures during early and/or late growth phases had more consistent, negative impacts on YRN and/or N(yield) for all crops, except oilseed rape. In addition to substantial variability caused by the environment, it was evident that genetic improvements in YRN have taken place. Hence, YRN can be improved by cultivar selection and through favouring crops with high YRN such as oat in crop rotations.
  • Authors:
    • Meca, A. V.
    • Popescu, N.
  • Source: Annals of the University of Craiova - Agriculture, Montanology, Cadastre Series
  • Volume: 40
  • Issue: 2
  • Year: 2010
  • Summary: Within our country conditions the wheat, rye, barley, oilseed rape and pea-oat fodder are sown in autumn. They may be grown after crops that are harvested during summer or perennial crops or pastures that are included is crop rotation schemes. In the conditions of our country, crops that are harvested during the summer are: pea-oat fodder, pea, early potato, barley and wheat. After harvesting these crops, there must be done, immediately, the summer plowing because the soil is still moist, resulting a good quality plowing. Any delay conducts to diminishing the yields. Usually, the summer plow is made at 18-20 cm depth. Deeper plow are not necessary on most soil types from our country. Twenty cm deeper plow is need only on clayey soil that easily compacts, when the soil is highly infested by weeds, covered by high straw or when in the last year there was made a shallow plow. Summer plow, no matter the depth must be done along with harrow after plow. During the fall, till drilling, the soil has to be harrowed in order to destroy weeds and to maintain soil loosened.
  • Authors:
    • Bengtson, L. E.
    • Fagre, D.
    • Pederson, G.
    • Zeyuan, Q.
    • Prato, T.
    • Williams, J. R.
  • Source: Environmental Management
  • Volume: 45
  • Issue: 3
  • Year: 2010
  • Summary: Potential economic impacts of future climate change on crop enterprise net returns and annual net farm income (NFI) are evaluated for small and large representative farms in Flathead Valley in Northwest Montana. Crop enterprise net returns and NFI in an historical climate period (1960-2005) and future climate period (2006-2050) are compared when agricultural production systems (APSs) are adapted to future climate change. Climate conditions in the future climate period are based on the A1B, B1, and A2 CO(2) emission scenarios from the Intergovernmental Panel on Climate Change Fourth Assessment Report. Steps in the evaluation include: (1) specifying crop enterprises and APSs (i.e., combinations of crop enterprises) in consultation with locals producers; (2) simulating crop yields for two soils, crop prices, crop enterprises costs, and NFIs for APSs; (3) determining the dominant APS in the historical and future climate periods in terms of NFI; and (4) determining whether NFI for the dominant APS in the historical climate period is superior to NFI for the dominant APS in the future climate period. Crop yields are simulated using the Environmental/Policy Integrated Climate (EPIC) model and dominance comparisons for NFI are based on the stochastic efficiency with respect to a function (SERF) criterion. Probability distributions that best fit the EPIC-simulated crop yields are used to simulate 100 values for crop yields for the two soils in the historical and future climate periods. Best-fitting probability distributions for historical inflation-adjusted crop prices and specified triangular probability distributions for crop enterprise costs are used to simulate 100 values for crop prices and crop enterprise costs. Averaged over all crop enterprises, farm sizes, and soil types, simulated net return per ha averaged over all crop enterprises decreased 24% and simulated mean NFI for APSs decreased 57% between the historical and future climate periods. Although adapting APSs to future climate change is advantageous (i.e., NFI with adaptation is superior to NFI without adaptation based on SERF), in six of the nine cases in which adaptation is advantageous, NFI with adaptation in the future climate period is inferior to NFI in the historical climate period. Therefore, adaptation of APSs to future climate change in Flathead Valley is insufficient to offset the adverse impacts on NFI of such change.
  • Authors:
    • Skuodiene, R.
    • Repsiene, R.
  • Source: Žemdirbystė (Agriculture)
  • Volume: 97
  • Issue: 4
  • Year: 2010
  • Summary: The current paper presents the results of experiments carried out at the Lithuanian Institute of Agriculture's Vezaiciai Branch during the period 2005-2009 on a Dystric Albeluvisol (ABd). We explored the effects of farmyard manure, alternative organic and lime fertilisers on soil agrochemical indicators and their relationship with weed incidence in a crop rotation (winter wheat -> lupine-oats mixture -> winter oilseed rape -> spring barley undersown with perennial grasses). Unlimed and farmyard manure - unfertilised soil was very acid, with a pH(KCl) of 4.0-4.3, hydrolytic acidity of 56.32-68.11 mequiv kg(-1) and mobile Al of 77.8-143.7 mg kg(-1). In unlimed soil applied with 40 and 60 t ha(-1) rates of farmyard manure hydrolytic acidity declined to 56.78-40.52 mequiv kg(-1), the content of mobile Al dramatically declined to 39.3-8.5 mg kg(-1), pH(KCl) increased to 4.3-4.6. Unlimed and farmyard manure-unfertilised soil contained 678-777.3 mg kg(-1) of exchangeable Ca and 157.7-163.3 mg kg(-1) of exchangeable Mg. In the soil fertilised with farmyard manure the content of exchangeable Ca increased by 1.4-2.8 times and that of exchangeable Mg by 1.0-1.5 times. In limed soil, the acidity was most markedly reduced by lime fertilisers, only traces (1.0-0.9 mg kg(-1)) of mobile Al were identified, a significant reduction in hydrolytic acidity occurred and pH(KCl) increased. Through the application of all organic fertilisers hydrolytic acidity declined by 17-18%, pH(KCl) value increased by 6-7%, compared with the limed soil. The highest increase (1.3-1.5 times) in exchangeable Ca content resulted from lime fertilisers, while exchangeable Mg content increased by up to 1.5 times. In limed and organically fertilised soil the highest contents of exchangeable Ca and Mg (2917.3-1949.0 mg kg(-1) and 322.7-243.0 mg kg(-1)) were recorded in the treatments applied with 60 t ha(-1) of farmyard manure. Alternative organic fertilisers were not more effective than farmyard manure in reducing soil acidity. The effects of the agricultural practices applied on the crop weed incidence manifested themselves in all experimental years. In the first year of organic fertiliser effect (in the winter wheat crop), strong correlations were established between soil agrochemical indicators and weed number and mass. In the second year of effect, due to the adverse weather conditions and poorer weed suppression capacity of lupine, the relationship between the number of weeds, their mass and individual agrochemical indicators was insignificant, except for that between weed mass and mobile Al content. Strong correlations were established in the third and fourth years of effect for winter oilseed rape and barley crops, respectively.
  • Authors:
    • Bathgate, A.
    • Lawes, R. A.
    • Robertson, M. J.
    • Byrne, F.
    • White, P.
    • Sands, R.
  • Source: Crop and Pasture Science
  • Volume: 61
  • Issue: 3
  • Year: 2010
  • Summary: Break crops (e. g. pulses, lupins, canola, oats) underpin the continued profitability of cereal (wheat or barley) based cropping sequences. The area sown on farms to break crops varies widely across geographical regions according to climate, soil type mix, enterprise mix (crop v. livestock), and other constraints such as the prevalence of soil-borne disease. Given recent fluctuations in the area of established break crops in Western Australia, there are concerns about their long-term prospects in the farming system. A survey of the area and grain yield of break crops on-farm was combined with whole-farm bio-economic modelling to determine the upper limit to the area of break crops on representative farms in 4 agro-climatic regions. Sensitivity analysis was conducted to ascertain the potential effects of varying commodity prices (sheep and grain), costs of production, and assumptions on the yield of break crops and the boost to the yield of following cereals. The survey revealed that the two dominant break crops, lupins and canola, occupied 8-12% and 8-9%, respectively, of farm area on those farms that grew them in the medium-rainfall zone and this declined to 6-8% and 7-10% in the drier region. Nevertheless, the modelling results show that break crops are an important component of the farming system, even where the area is small, and the response of whole-farm profit to percent of the farm allocated to break crops is relatively. at near the optimum of 23-38%. The modelled area of break crops at maximum profit is higher than that found in farm surveys. The discrepancy could possibly be explained by the lower break crop yields realised by farmers and a reduced boost to cereal yields following break crops than assumed in models. Also, deterministic models do not account for risk, which is an important consideration in the decision to grow break crops. However, the yield difference does not explain the discrepancy entirely and raises questions about farmer motivations for adoption of break crops. The scope for increased area of break crops beyond 23-38% of the farm is limited, even with increases in the yield enhancements in subsequent cereal crops, higher break crop prices, and higher fertiliser costs. Further research is required to better quantify costs and benefits of break crops in Western Australian farming systems.
  • Authors:
    • Munier-Jolain, N. M.
    • Kurstjens, D. A. G.
    • Colbach, N.
    • Dalbies, A.
    • Dore, T.
  • Source: European Journal of Agronomy
  • Volume: 32
  • Issue: 3
  • Year: 2010
  • Summary: Because of environmental and health safety issues. it is necessary to develop strategies that do not rely on herbicides to manage weeds. Introducing temporary grassland into annual crop rotations and mechanical weeding are the two main features that are frequently used in integrated and organic cropping systems for this purpose. To evaluate the contribution of these two factors in interaction with other cropping system components and environmental conditions, the present study updated an existing biophysical model (i.e. ALOMYSYS) that quantifies the effects of cropping system oil weed dynamics. Based oil previous experiments, new sub-models were built to describe the effects on plant survival and growth reduction of mechanical weeding resulting from weed seedling uprooting and covering by soil, and those of grassland mowing resulting from tiller destruction. Additional modifications described the effect of the multiyear crop canopy of grassland on weed survival, growth, development and seed return to the soil. The improved model was used to evaluate the weed dynamics over 27 years in the conventional herbicide-based cropping system most frequently observed in farm Surveys (i.e. oilseed rape/winter wheat/winter barley rotation with Superficial tillage) and then to test prospective non-chemical scenarios. Preliminary simulations tested a large range of mechanical weeding and mowing strategies, varying operation frequencies, dates and, in the case of mechanical weeding, characteristics (i.e. tool, working depth, tractor speed). For mechanical weeding soon after sowing, harrowing was better than hoeing for controlling weed seed production. The later the operation, the more efficient the hoeing and the less efficient the harrowing. Tractor speed had little influence. Increasing tilling depth increased plant mortality but increased weed seed production because of additional seed germination triggering by the weeding tool. Decreasing the interrow width for hoeing was nefarious for weed control. The best combinations were triple hoeing in oilseed tape and sextuple harrowing in cereals. The best mowing strategy was mowing thrice, every 4-6 weeks, starting in mid-May. The best individual options were combined, simulated over 27 years and compared to the herbicide-based reference system. If herbicide applications were replaced solely by mechanical weeding, blackgrass infestation Could not be satisfactorily controlled. If a three-year lucerne was introduced into the rotation, weed infestations were divided by ten. Replacing chisel by mouldboard ploughing before winter wheat reduced weed infestations at short, medium and long term to a level comparable to the herbicide-based reference system. (C) 2009 Elsevier B.V. All rights reserved.