• Authors:
    • Deen, W.
    • Janovicek, K.
    • Meyer-Aurich, A.
    • Weersink, A.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 5
  • Year: 2006
  • Summary: The objective of our research was to identify economically efficient corn (Zea mays L.) based tillage-rotation combinations using a 20-yr data set from a long-term experiment in Ontario, Canada. Seven rotations in two tillage systems (moldboard and chisel plow) were analyzed. We found multiple benefits associated with diversifying rotations in both tillage systems The integration of soybean [Glycine mar (L.) Merr.] or soybean and wheat (Triticum aestivum L.) resulted in 7 to 11% higher corn yields in the chisel tillage system. In the plow tillage system corn yield in rotation with soybean and wheat increased by 5%, when wheat was underseeded with red clover (Trifolium pratense L.). These diversified rotations resulted in an increase in yearly net returns of $51 to $64 in the moldboard tillage system and $96 to $108 in the chisel tillage system. The diversification of rotations reduces variance of net return and thus makes the rotations attractive to risk averse producers. Furthermore diversified rotations showed less response to price changes. Diversified rotations evaluated in this study also proved to be less affected by increasing energy costs. Red clover seeded into wheat resulted in 5% higher yields for the following corn crop in the moldboard system. Rotations that included red clover cover lowered production risk but did not have higher net returns than comparable rotations without red clover. However, the potential for red clover to reduce N fertilization requirements for the following corn, was not considered in this study. Yield penalties due to chisel plowing with financial consequences were only observed in continuous corn. In all other rotations the effect of tillage was negligible. An increase in energy costs forces farmers to switch to crops with lower inputs rather than switch to reduced tillage.
  • Authors:
    • Kevan, P. G.
    • Belaoussoff, S.
    • Clements, D. R.
    • Murphy, S. D.
    • Swanton, C. J.
  • Source: Weed Science
  • Volume: 54
  • Issue: 1
  • Year: 2006
  • Summary: In a 6-yr study on four farms (36 fields) in Ontario, Canada, we tested the effects of tillage (moldboard, chisel plow, no tillage) and crop rotations (continuous corn, corn-soybean, corn-soybean-winter wheat) on emerged and seedbank weed species diversity and density Aside from the imposed experimental treatments, all other management was generally consistent among farms. Tillage had the largest effect on weed diversity and density. No tillage promoted the highest weed species diversity, chisel plow was intermediate, and moldboard plow resulted in the lowest species diversity. These results are consistent with ecological succession theory. The increase in weed species diversity resulted from 20 species being associated with no tillage systems, 15 of which were winter annuals, biennials, or perennials. Emerged weed density was affected only by tillage. Over 6 yr, seedbank declined in no-tillage systems from 41,000 to 8,000 seeds m(-3). Crop yields were not affected by tillage or crop rotation. In practical terms, reduced tillage in combination with a good crop rotation may reduce weed density and expenditures on weed management.
  • Authors:
    • Mallory-Smith, C.
    • William, R. D.
    • Peachey, B. E.
  • Source: Weed Technology
  • Volume: 20
  • Issue: 1
  • Year: 2006
  • Summary: The effects of spring tillage sequence on summer annual weed populations were evaluated over two cycles of a 3-year crop rotation of snap beans ( Phaseolus vulgaris), sweetcorn ( Zea mays), and winter wheat ( Triticum aestivum). Continuous no-till (N) planting of vegetable crops each spring (NNNN) reduced summer annual weed density by 63-86% compared with that of continuous conventional tillage (CCCC), depending upon the site and herbicide level. Hairy nightshade ( Solanum sarrachoides) populations were reduced by 88 to 96% when spring tillage was eliminated from the crop rotation. The effects of the NNNN spring tillage sequence on weed density were similar at two sites even though the crop rotations at the two sites began with different crops. The rotational tillage sequence of NCNC at the East site, in a crop rotation that began with maize, reduced summer annual weed density by 46-51% compared with that of continuous conventional tillage and planting (CCCC) at low and medium herbicide rates, respectively. In contrast, the tillage sequence of CNCN in the same crop rotation and at the same site increased weed density by 80% compared with that of CCCC at a low herbicide rate. The effects of the NCNC and CNCN rotational tillage sequences on weed density were reversed at the West site, and was probably caused by pairing sweetcorn with conventional tillage rather than no-tillage. The reduction in summer annual weed density caused by reduced spring tillage frequency did not significantly increase crop yields.
  • Authors:
    • Spiridon, C.
    • Rotarescu, M.
    • Raranciuc, S.
    • Guran, M.
    • Popov, C.
    • Vasilescu, S.
    • Gogu, F.
  • Source: Probleme de Protectia Plantelor
  • Volume: 34
  • Issue: 1/2
  • Year: 2006
  • Summary: This paper summarizes the harmful pests and pathogens infecting cereals and legumes (grown for grain, industrial purposes and fodder production) in Romania in 2005. The soil and seed pathogens include: Tilletia spp. and Fusarium spp. in wheat; Ustilago nuda [ U. segetum var. nuda] and Pyrenophora graminea in barley; Pythium spp. and Fusarium spp. in maize; Sclerotinia sclerotiorum, Botrytis cinerea, Plasmopara helianthi [ Plasmopara halstedii] and Orobanche cumana in sunflower; and Fusarium spp. and Pythium spp. in pea, bean and soyabean. Foliar and ear diseases include: Erysiphe spp., Septoria spp., Pyrenophora graminea, Puccinia spp. and Fusarium spp. in wheat and barley; U. maydis [ U. zeae], Helminthosporium turcicum [ Setosphaeria turcica], Fusarium spp. and Nigrospora oryzae [ Khuskia oryzae] in maize; Sclerotinia sclerotiorum, Botrytis cinerea, Alternaria spp. and Phomopsis spp. in sunflower; and Erysiphe spp. and Septoria spp. in rape. Soil pests included: Zabrus tenebrioides and Agriotes spp. in spiked cereals; Tanymecus dilaticollis and Agriotes spp. in maize and sunflower; Delia platura in beans; Phyllotreta atra in rape and mustard; Aphthona euphorbiae in linseed; and Sitona spp. and Agriotes spp. in lucerne and clover. Pests that attack aerial parts and seeds include: Eurygaster integriceps, Lema melanopa [ Oulema melanopus] and Anisoplia spp. in wheat, barley and oats; Ostrinia nubilalis and Diabrotica virgifera virgifera in maize; Thrips linarius in linseed; Athalia rosae, Meligethes aeneus and Brevicoryne brassicae in rape and mustard; Hypera variabilis [ H. postica], Semiothisa clathrata, Bruchophagus roddi and Subcoccinella vigintiquattuorpunctata in lucerne and clover.
  • Authors:
    • Healy, K.
    • Reichstein, I.
    • Murray, B.
  • Source: 9th International Working Conference on Stored Product Protection -- New Chemicals and Food Residues PS3-2-6324
  • Year: 2006
  • Summary: The National Residue Survey (NRS) is an operational unit of the Australian Government Department of Agriculture, Fisheries and Forestry. NRS has managed and operated residue testing programs (including meat products and grains) for over 40 years. The NRS Grains Residue Testing Program is fully industry funded via a 0.015% ad valorem levy on grain growers. This Residue Testing Program complements that undertaken by grain marketers/handlers from grower receivals to bulk storage. Noting that NRS does not have a regulatory role, the Grains Program is viewed as providing independent verification of the residue status of Australian grain at the point of out-turn for export and for receival at grain processors such as flour mills. The Grains Program covers wheat, barley, oat, sorghum, canola, field pea, chickpea and lupin. By 2007, it is expected to extend to all tradeable grains including lentil, soybean, maize, triticale, sunflower, mung bean and faba/broad bean. Each year, the Grains Program is independently reviewed and a prospective monitoring plan circulated to the Grains Council of Australia and State affiliates, and peak grain industry bodies for endorsement. The Grains Program monitoring plan specifies that approximately 5,500 grain samples are collected per annum from export shipments and containers, flour mills, feedmills, feedlots and maltsters. About 4,000 samples are collected from export shipments where every hatch of every ship from every Australian grain export terminal is sampled during loading. The monitoring plan stipulates that samples be sent to an accredited proficiency-tested laboratory and residue testing results reported to the grain marketer/handler within 14 days of sample collection. Grain samples are subjected to a chemical screen covering a range of insecticides, fungicides and environmental contaminants. These residue testing results are reported against Australian MRLs established by Food Standards Australia and New Zealand.
  • Authors:
    • Wojciak, H.
    • Adamiak, J.
    • Rychcik, B.
  • Source: Plant, Soil and Environment
  • Volume: 52
  • Issue: Special Issue
  • Year: 2006
  • Summary: A field experiment was conducted during 1992-2004 on Luvisols (formed from silty light loam) at the Experimental Station at Bacyny to investigate the response of the most important plants cultivated in Poland to monocultural cultivation. Twelve plant species were cultivated in crop rotations: (A) potato-oats-flax-winter rye-faba bean-winter triticale; (B) sugarbeet-maize-spring barley-pea-winter rape-winter wheat, and (C) each of the species in monocultures. The organic matter content in the soil plough layer (0-250 mm) in 1992, 1998 and 2004 is presented. Fractionation of humus was carried out with the Duchaufour and Jacquin method. Under the conditions of the crop rotations, organic matter content slightly increased; similar tendencies were observed in most monoculture fields. The lowest content of organic C was recorded under the conditions of continuous cultivation of pea, maize and faba bean. Humins and humus compounds (extraction II and III) had a dominant share among the determined fractions. Humic acids prevailed over fulvic acids in the crop rotation cultivations and in the most monoculture fields. However, the prevalence of fulvic acids was found under the conditions of continuous cultivation of sugarbeet, potato and winter rye.
  • Authors:
    • Harker, K. N.
    • Beckie, H. J.
    • Blackshaw, R. E.
    • Upadhyay, B. M.
    • Smith, E. G.
    • Clayton, G. W.
  • Source: Canadian Journal of Plant Science
  • Volume: 86
  • Issue: 4
  • Year: 2006
  • Summary: Integrated weed management (IWM) systems that combine seeding date, seeding rate, herbicide rate, and timing of nitrogen (N) fertilizer application were assessed for their economic performance in the Dark Brown and Black soil zones. A barley-field pea IWM system in the Black soil zone at Lacombe, Alberta, and a wheat-canola IWM system in the Dark Brown soil zone at Lethbridge, Alberta, and Scott, Saskatchewan, were used to assess contributions of seeding date (April or May), seeding rate (recommended or 150% of recommended), fertilizer timing (fall or spring), and in-crop herbicide rate (50% or 100% of recommended). The factorial set of treatments was applied in 4 consecutive years at each site. For barley-field pea production, the highest contribution margin (CM) (returns over variable production costs) was earned with 50% of the recommended herbicide rate, spring application of N fertilizer, seeding barley later at the high seeding rate, and seeding field pea early at the recommended seeding rate. This IWM system had a CM benefit of at least $51 ha(-1) compared with current common practices. The wheat-canola system results were site specific. At Lethbridge, it was more profitable to use 50% of recommended herbicide rates and to seed both crops early, with an early seeding date being very important for canola. The CM of this IWM system was $48 ha(-1) higher than current common practices. At Scott, the wheat-canola system was more profitable with spring fertilizer application, 50% of the recommended herbicide rate, and an early seeding date for canola. The best IWM system had a CM $15 to $75 ha-1 higher, depending on the year, than common practices. Our results confirmed the economic merits of using IWM practices for cereal-oilseed and cereal-pulse cropping systems in these regions of western Canada.
  • Authors:
    • Duchovskiene, L.
    • Starkute, R.
    • Zalatorius, V.
  • Source: Straipsnis leidinyje: Sodininkystė ir daržininkystė
  • Volume: 25
  • Issue: 4
  • Year: 2006
  • Summary: In 2003-05 in Lithuanian Institute of Horticulture, in trial field for ecologically grown vegetables, plant availability for green manure and its influence on ecologically grown onions yield were evaluated. Investigated plants included: barley; barley with undersown clover; summer wheat, peas and oats; and rape. Control treatment was black fallow. The biomass of plants for green manure leaves in the soil was evaluated under different amounts of organic matter. The highest amount of green matter (43.2 t/ha) was from peas and oats; summer wheat showed 32.5 t/ha; barely with undersown clover, 30.2 t/ha; and the lowest was from barely and rape (24.5 and 27.0 t/ha, respectively). There were no significant differences in the number of Thrips tabaci between treatments. Green manure from peas and oats increase onion yield by 3.1%; green manure from summer wheat by 5.7%; and green manure from barely with undersown clover by 7.3%. The lowest impact for onion yield has had green manure from barely and rape. The highest number of weeds (191 unit/m 2) was found in onions grown after barely with undersown clover, while the lowest number of 29 unit/m 2 was in onions grown after peas and oats.
  • Authors:
    • Rosenberg, N. J.
    • Izaurralde, R. C.
    • Thomson, A. M.
    • He, X. X.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 114
  • Issue: 2/4
  • Year: 2006
  • Summary: For thousands of years, the Huang-Hai Plain in northeast China has been one of the most productive agricultural regions of the country. The future of this region will be determined in large part by how global climatic changes impact regional conditions and by actions taken to mitigate or adapt to climate change impacts. One potential mitigation strategy is to promote management practices that have the potential to sequester carbon in the soils. The IPCC estimates that 40 Pg of C could be sequestered in cropland soils worldwide over the next several decades; however, changes in global climate may impact this potential. Here, we assess the potential for soil C sequestration with conversion of a conventional till (CT) continuous wheat system to a wheat-corn double cropping system and by implementing no till (NT) management for both continuous wheat and wheat-corn systems. To assess the influence of these management practices under a changing climate, we use two climate change scenarios (A2 and B2) at two time periods in the EPIC agro-ecosystem simulation model. The applied climate change scenarios are from the HadCM3 global climate model for the periods 2015-2045 and 2070-2099 which projects consistent increases in temperature and precipitation of greater than 5degreesC and up to 300 mm by 2099. An increase in the variability of temperature is also projected and is, accordingly, applied in the simulations. The EPIC model indicates that winter wheat yields would increase on average by 0.2 Mg ha -1 in the earlier period and by 0.8 Mg ha -1 in the later period due to warmer nighttime temperatures and higher precipitation. Simulated yields were not significantly affected by imposed changes in crop management. Simulated soil organic C content was higher under both NT management and double cropping than under CT continuous wheat. The simulated changes in management were a more important factor in SOC changes than the scenario of climate change. Soil C sequestration rates for continuous wheat systems were increased by an average of 0.4 Mg ha -1 year -1 by NT in the earlier period and by 0.2 Mg ha -1 year -1 in the later period. With wheat-corn double cropping, NT increased sequestration rates by 0.8 and 0.4 Mg ha -1 year -1 for the earlier and later periods, respectively. The total C offset due to a shift from CT to NT under continuous wheat over 16 million hectares in the Huang-Hai Plain is projected to reach 240 Tg C in the earlier period and 180 Tg C in the later period. Corresponding C offsets for wheat-corn cropping are 675-495 Tg C.
  • Authors:
    • Roostalu, H.
    • Astover, A.
    • Vasiliev, N.
    • Matveev, E.
  • Source: Agronomy Research
  • Volume: 4
  • Issue: 1
  • Year: 2006
  • Summary: For analysing agronomic efficiency and economic criteria, the results of variety comparison tests of cereals, performed in Estonia during twenty years, national statistics and the data of the survey of the Farm Accountancy Data Network (FADN) for 2000-2003 were summarised. Farms whose grain production contributed more than 75% to total output were selected for analysis. At present only -40-50% of the real yield potential of cereals is realised. In case of oilseed rape the utilisation of the yield potential is 60-65%. Among the cereals, the largest share is accounted for by barley with 25-43% and wheat with 15-29%. During four years (2000-2003), total inputs increased 21%. Total inputs were the highest in large farms. As an average for 2000-2003 FADN grain producers were profitable in all size groups but consideration of total labour costs indicates that small grain farms were unprofitable. Average farm family income was 1,376 EEK ha(-1). There is a non-linear relationship between farm size and economic indicators. Farm family income increases up to similar to 400 ha. The increase is most significant in the size range 40-200 ha where the increase in farm size by one hectare increases profit by 7.6 EEK ha(-1). Further increase will decelerate profit and the most efficient use of labour occurs in this size range as well. Cost benefit is the highest for farm size ranging from similar to 150 to 400 ha. Profit decreases with the increase in one annual work unit by 508 EEK ha(-1) and production becomes unprofitable in case a grain farm employs more than 2.6 workers per 100 ha.