• Authors:
    • Lehoczky, É.
    • Kismányoky, A.
  • Source: Agrokémia és Talajtan
  • Volume: 59
  • Issue: 1
  • Year: 2010
  • Summary: A long-term soil tillage experiment was conducted in 2005 to 2008 on a Ramann-type brown forest soil (Eutric Cambisol) in Keszthely, Hungary, with different cultivation methods (no-till, drill, disc tillage, conventional tillage (ploughing)) and five increasing N doses. Treatment A was the cultivation method: conventional tillage (ploughing), no-till, drill, disc tillage; and Treatment B was N fertilizer application: N 0-N 4 (0, 120, 180, 240 and 300 for maize, and 0, 120, 160, 200 and 240 kg/ha per ton for wheat, respectively). Both plots received a blanket application of 100 kg P 2O 5/ha and 100 kg K 2O/ha. With soil cultivation and N fertilization treatments, winter wheat yield varied between 2.5 and 6.0, while maize yield ranged from 6 to 10 t/ha. The influence of the annual circumstances (mostly rainfall) on the yields was measurable and from time to time statistically significant. The different amounts of N fertilizer significantly increased the yields of maize and wheat. The highest increases were found in the case of N 1 and N 2 treatments. The maximum yields of maize and wheat were obtained with the 200-250 kg N/ha doses. On the average of years, the largest weed cover (28%) was recorded in the no-tillage treatment, while the ploughing system was the least weedy (10-15%).
  • Authors:
    • Ediriwickrema, J.
    • Shao, Y.
    • Lunetta, R. S.
    • Lyon, J. G.
  • Source: International Journal of Applied Earth Observation and Geoinformation
  • Volume: 12
  • Issue: 2
  • Year: 2010
  • Summary: The Moderate Resolution Imaging Spectrometer (MODIS) Normalized Difference Vegetation Index (NDVI) 16-day composite data product (MOD12Q) was used to develop annual cropland and crop-specific map products (corn, soybeans, and wheat) for the Laurentian Great Lakes Basin (GLB). The crop area distributions and changes in crop rotations were characterized by comparing annual crop map products for 2005, 2006, and 2007. The total acreages for corn and soybeans were relatively balanced for calendar years 2005 (31,462 km(2) and 31,283 km(2), respectively) and 2006 (30,766 km(2) and 30,972 km(2), respectively). Conversely, corn acreage increased approximately 21% from 2006 to 2007, while soybean and wheat acreage decreased approximately 9% and 21%, respectively. Two-year crop rotational change analyses were conducted for the 2005-2006 and 2006-2007 time periods. The large increase in corn acreages for 2007 introduced crop rotation changes across the GLB. Compared to 2005-2006, crop rotation patterns for 2006-2007 resulted in increased corn-corn, soybean-corn, and wheat-corn rotations. The increased corn acreages could have potential negative impacts on nutrient loadings, pesticide exposures, and sediment-mediated habitat degradation. Increased in US corn acreages in 2007 were related to new biofuel mandates, while Canadian increases were attributed to higher world-wide corn prices. Additional study is needed to determine the potential impacts of increases in corn-based ethanol agricultural production on watershed ecosystems and receiving waters. Published by Elsevier B.V.
  • 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:
    • Holzapfel, C. B.
    • Kutcher, H. R.
    • Gan, Y.
    • Brandt, S. A.
    • May, W. E.
    • Lafond, G. P.
  • Source: Canadian Journal of Plant Science
  • Volume: 90
  • Issue: 5
  • Year: 2010
  • Summary: Differences in response to nitrogen (N) fertilizer will affect the production economics of field crops. Currently, there is limited information comparing the agronomic and economic performance of juncea canola (Brassica juncea L.) and sunflower (Helianthus annuus L.) to napus canola (Brassica napus L.) and flax (Limon ustitatissimum L.) in Saskatchewan under no-till practices. A study of these species was carried out at five Saskatchewan locations over 3 yr and included eight nitrogen rates. All four species had a curvilinear increase in grain yield as N rate increased with the largest yield response observed in napus canola to as much as 200 kg N ha I. The majority of the increase in flax grain yield occurred as the N rate increased from 10 to 90 kg ha(-1), while most of the increase in grain yield of juncea canola and sunflower occurred as N increased from 10 to 70 kg ha(-1). Biplot analysis indicated that grain yield variation was reduced at and above 50 kg N ha(-1) in flax, napus canola and juncea canola, but not in sunflower. Analysis indicated that a wide range of N rates would provide a similar adjusted gross return within each crop with the exact N range being determined by crop price and nitrogen cost. The N rate affected the kernel weight of sunflower but not the kernel weight of other crops. The protein concentration of all the species increased as N rate increased. Seed oil concentration tended to decrease as the N rate increased, but this was not consistent. In conclusion, higher yielding cultivars of sunflower and juncea canola are needed before they will replace a large acreage of flax or napus canola; however, in the drier regions of the Saskatchewan there is potential to expand sunflower production.
  • 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:
    • Thorup-Kristensen, K.
    • Dresboll, D. B.
  • Source: Soil Use and Management
  • Volume: 26
  • Issue: 1
  • Year: 2010
  • Summary: The significance of incorporation date of a catch crop on the nitrogen supply for the subsequent crop, the N effect (N(eff)), was examined. Winter rye was grown as a catch crop for 3 years during the autumn, and incorporated on five dates, two in the autumn and three in the spring. Two of the winters had high precipitation, and the N(eff) was small at the early autumn incorporation date, but increased when incorporation was delayed into late autumn and further increased by early spring incorporation. In the third winter, which was very dry, the N(eff) was negative at all incorporation dates, with the negative effect gradually increasing in value the later the incorporation date. In all 3 years the N(eff) was reduced when incorporation was delayed from early spring until later in the spring. The main processes determining this pattern were found to be (1) the risk of leaching of N mineralized after catch crop incorporation, which can reduce the N(eff) at early incorporation under wet conditions, (2) pre-emptive competition which can reduce the N(eff) when incorporation is delayed until later in the spring, and in dry conditions is already apparent during the autumn, and (3) catch crop growth leading to carbon gain and increased C/N ratio which decreases mineralization and thus the N(eff) after delayed incorporation in the spring. Lack of time for catch crop N uptake prior to early incorporation, or lack of time for N mineralization after late incorporation which might also reduce the N(eff) did not appear to be important in our experiment. The results show that catch crops grown in high rainfall areas on sandy soils should be incorporated later than those in low rainfall areas on nitrate retentive soils.
  • Authors:
    • Krogstad, T.
    • Bechmann, M.
    • Aronsson, H.
    • Ulen, B.
    • Øygarden, L.
    • Stenberg, M.
  • Source: Soil Use and Management
  • Volume: 26
  • Issue: 2
  • Year: 2010
  • Summary: In Scandinavia high losses of soil and particulate-bound phosphorus (PP) have been shown to occur from tine-cultivated and mouldboard-ploughed soils in clay soil areas, especially in relatively warm, wet winters. The omission in the autumn of primary tillage (not ploughing) and the maintenance of a continuous crop cover are generally used to control soil erosion. In Norway, ploughing and shallow cultivation of sloping fields in spring instead of ploughing in autumn have been shown to reduce particle transport by up to 89% on highly erodible soils. Particle erosion from clay soils can be reduced by 79% by direct drilling in spring compared with autumn ploughing. Field experiments in Scandinavia with ploughless tillage of clay loams and clay soils compared to conventional autumn ploughing usually show reductions in total P losses of 10-80% by both surface and subsurface runoff (lateral movements to drains). However, the effects of not ploughing during the autumn on losses of dissolved reactive P (DRP) are frequently negative, since the DRP losses without ploughing compared to conventional ploughing have increased up to fourfold in field experiments. In addition, a comprehensive Norwegian field experiment at a site with high erosion risk has shown that the proportion of DRP compared to total P was twice as high in runoff water after direct drilling compared to ploughing. Therefore, erosion control measures should be further evaluated for fields with an erosion risk since reduction in PP losses may be low and DRP losses still high. Ploughless tillage systems have potential side-effects, including an increased need for pesticides to control weeds [e.g. Elytrigia repens (L.) Desv. ex Nevski] and plant diseases (e.g. Fusarium spp.) harboured by crop residues on the soil surface. Overall, soil tillage systems should be appraised for their positive and negative environmental effects before they are widely used for all types of soil, management practice, climate and landscape.