• Authors:
    • Lang, C.
    • Rios, E.
    • Moraes, A.
    • Carvalho, P.
    • Medrado, R.
    • Lopes, E.
  • Source: Scientia Agraria
  • Volume: 12
  • Issue: 2
  • Year: 2011
  • Summary: This study aimed to evaluate the decomposition of the residual dry mass and the initial release of nitrogen from different coverages winter for the subsequent cultivation of maize. The work was conducted in Major Vieira, SC, on a family property. The experimental design was a randomized block, with five treatments (alternative soil cover) and three replications. The treatments: (a) consortium of oat ( Avena strigosa)+ryegrass ( Lolium multiflorum)+vetch ( Vicia spp.)+vesiculoso clover ( Trifolium vesiculosum), with grazing and nitrogen fertilization (100 kg of N); (b) Grassland of black oat+ryegrass+vetch+clover vesiculoso, with grazing and without nitrogen fertilization; (c) coverage (oat+ryegrass+vetch+vesiculoso clover), without grazing and without nitrogen fertilization; (d) forage turnip ( Raphanus sativus), without grazing and without nitrogen fertilization, and (e) fallow (control). The rate of decay was measured through pockets of decomposition (litter bags), collected in seven seasons during the corn crop. The turnip forage was the treatment that was more difficult to decompose according to their chemical characteristics. This limited the supply of nitrogen for the corn crop. Treatment coverage consortium made rapid initial release of N and thus was considered the most appropriate for use in succession with the corn crop. The grazing influenced the release of nitrogen, mainly by the lower amount of total dry mass produced. The grain yield of maize was not influenced by soil cover.
  • Authors:
    • Dopieraa, U.
    • Rosada, J.
    • ukaszyk, J.
  • Source: Progress in Plant Protection
  • Volume: 51
  • Issue: 1
  • Year: 2011
  • Summary: Total concentration of copper was determined by means of AAS in soil and cereal samples collected from the region influenced by air and dust emission from Copper Smelter GOGOW. Studies covered the agricultural area of 6 600 hectares (former protective zone + external belt). The studies revealed that copper, either accumulated in the soils or coming from the current emission, did not cause the phytotoxic effect on cultivated cereals. The obtained results revealed the effectiveness of eco-friendly activities taken by the Smelter for the safety's sake of the neighboring agricultural environment.
  • Authors:
    • Costa, O.
    • Ziech, M.
    • Nornberg, J.
    • Bermudes, R.
    • Viegas, J.
    • Skonieski, F.
    • Meinerz, G.
  • Source: REVISTA BRASILEIRA DE ZOOTECNIA-BRAZILIAN JOURNAL OF ANIMAL SCIENCE
  • Volume: 40
  • Issue: 3
  • Year: 2011
  • Summary: The objective of this work was to evaluate the influence of species intercropped with ryegrass on the botanical and structural composition and the nutritional values of pastures in an agroecological transition system. It was evaluated ryegrass ( Lolium multiflorum Lam.) intercropped with black oats ( Avena strigosa Schreb.), white clover ( Trifolium repens L.) and forage peanut ( Arachis pintoi Krapov. & Gregory). It was used a complete random design with three treatments and three repetitions. The first grazing was done 21 days after emergence of the plants on the pastures with ryegrass and black oats and ryegrass and forage peanuts and 28 days after emergence on the pasture of ryegrass+white clover. The second grazing, on the pasture with ryegras+black oats, occurred 30 days after the first one, whereas on the other pastures, grazing occurred 37 days later. The rates of dry matter (DM) accumulation, from the beginning of period of exclusion until maximal production of dry matter were: 77.7; 75.0 and 71.3 kg/ha/day of DM for the pastures intercropped with white clover, forage peanut and black cover, respectively. Leaf/culm ratio until second grazing, was high on all pastures. Reduction on contents of crude protein according to exclusion days on ryegrass+black oat pasture is lower than on pastures of ryegrass intercropped with white clover or forage peanut.
  • Authors:
    • Muys, B.
    • Hermy, M.
    • Govers, G.
    • Pina, A.
    • Valckx, J.
  • Source: Pedobiologia
  • Volume: 54
  • Issue: Supplement 1
  • Year: 2011
  • Summary: Some of the widely used cover crops in temperate agroecosystems (including species of the Brassicaceae and Poaceae) have been shown to exhibit allelopathic effects. In particular, various Brassicaceae have been reported to act as biofumigants against a variety of soil-borne pests through the release of i.a. isothiocyanates (ITC) from glucosinolate precursors. Although these allelochemicals may potentially reduce the need for application of synthetic pesticides, their effects on beneficial soil ecosystem engineers such as earthworms (Lumbricidae) have not been assessed yet. Food choice chambers were used to assess short-term food preferences of Lumbricus terrestris L. for lacy phacelia ( Phacelia tanacetifolia BENTH.), the Poaceae Italian ryegrass ( Lolium multiflorum LAM.) and oats ( Avena sativa L.), and the Brassicaceae yellow mustard ( Sinapis alba L.) and rapeseed ( Brassica napus L.) while litter bags were used to study long-term litter preference under field conditions. Habitat preference of L. terrestris was determined through simple habitat preference units. Ryegrass residues were a preferred food resource, both in fresh and partly decomposed state, over mustard, phacelia or rapeseed residues, and these were in turn more fed on than oats. Litter disappeared at a fast and variable rate from litter bags under field conditions. No clear relationships with residue C:N ratio were observed. Habitats in which living oat plants were present were avoided in comparison to habitats with bare soil or yellow mustard plants. In conclusion, brassicaceous cover crops are not preferred nor avoided by L. terrestris compared to the other cover crops in this study. Decreased ITC release and earthworm exposure under field conditions may further lower the risk of harmful effects, but further research on the long-term impact is needed.
  • Authors:
    • Hallikainen, A.
    • Kostiainen, E.
    • Turtiainen, T.
  • Source: Journal of Environmental Radioactivity
  • Volume: 102
  • Issue: 5
  • Year: 2011
  • Summary: A survey was carried out on the activity concentrations of 210Pb and 210Po in cereal grains produced in Finland. The cereal species were wheat ( Triticum aestivum), rye ( Secale cereale), oats ( Avena sativa) and barley ( Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean 210Pb/ 210Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg -1, respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from 210Pb and 210Po in cereal products for the adult male and female population are 22 and 17 Sv per year, respectively.
  • Authors:
    • Wellings, C.
  • Source: Euphytica
  • Volume: 179
  • Issue: 1
  • Year: 2011
  • Summary: Stripe rust, caused by Puccinia striiformis, has been an important disease of wheat, barley, rye, triticale and certain graminaceous hosts for centuries. The significance of the disease on cultivated cereals has waxed and waned according to the vagaries of climate, inoculum levels and susceptible varieties. A progressive understanding of pathogen biology has revealed levels of specialisation between and within host groups, and these had varying impacts on the hosts concerned. The most economically important form is P. striiformis f. sp. tritici ( Pst), the causal pathogen of stripe (yellow) rust of wheat, which is the major focus of this paper. The recent discovery of the perfect stage of Pst on Berberis spp. will encourage further work to uncover the potential importance of the sexual stage in pathogen biology in regions where Berberis spp. occur. A review of the evolution of pathotypes within Pst over the past 50 years reveals recurrent pandemics emanating from a combination of specific virulence in the pathogen population, wide scale cultivation of genetically similar varieties, and agronomic practices that led to high yield potential. When these factors operate in concert, regional stripe rust epidemics have proven to be dramatic, extensive and serious in terms of the magnitude of losses and the economic hardships endured. A review of these epidemics suggests that little progress has been made in containing the worst effects of epidemics. The current status of stripe rust was gauged from a survey of 25 pathologists and breeders directly associated with the disease. It was evident that Pst remains a significant threat in the majority of wheat growing regions of the world with potential to inflict regular regional crop losses ranging from 0.1 to 5%, with rare events giving losses of 5-25%. Regions with current vulnerability include the USA (particularly Pacific North West), East Asia (China north-west and south-west), South Asia (India, Pakistan, Nepal), Oceania (Australia, New Zealand), East Africa (Ethiopia, Kenya), the Arabian Peninsula (Yemen) and Western Europe (east England). The resources deployed to contain the worst effects of Pst will need to find a balance between training a new generation of breeders and pathologists in host-pathogen genetics, and an investment in infrastructure in IARCs and NARs.
  • Authors:
    • Oberforster, M.
    • Hammerl, S.
    • Zechner, E.
  • Source: Tagungsband der 61. Jahrestagung der Vereinigung der Pflanzenzuchter und Saatgutkaufleute Osterreichs, 23-25 November 2010, Raumberg-Gumpenstein, Osterreich. Ertrag vs. Qualitat bei Getreide, Ol und Eiweisspflanzen. Wheat stress
  • Year: 2011
  • Summary: Since 1903 cereal breeding takes place at Edelhof near Zwettl, Lower Austria. The main focus lies on the breeding of top-quality wheat for Europe, high-yielding wheat with medium quality, two-rowed winter barley, spring barley with a high percentage of plump seeds, early maturing quality oats, open-pollinating rye and varieties for organic farming. With the directive 2009/28/EG and the installation of a bio-ethanol plant in Austria, breeders interest in selecting cereals for ethanol production awaked. This means in particular field selection, investments in quality analyses and targeted projects, and furthermore the implementation of a new breeding programme (parallel to bread cereal breeding). From crossing to variety release several years pass by. Meanwhile, cereal breeders had to realize that from the bio-ethanol market there is no special interest in varieties specific for this purpose.
  • Authors:
    • Askegaard, M.
    • Olesen, J. E.
    • Kristensen, K.
    • Rasmussen, I. A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 142
  • Issue: 3-4
  • Year: 2011
  • Summary: Two main challenges facing organic arable farming are the supply of nitrogen (N) to the crop and the control of perennial weeds. Nitrate leaching from different organic arable crop rotations was investigated over three consecutive four-year crop rotations in a field experiment at three locations in Denmark (12 years in total). The experimental treatments were: (i) crop rotation, (ii) catch crop and (iii) animal manure. Nitrate leaching was estimated from measured soil nitrate concentration in ceramic suction cells and modelled drainage. There were significant effects on annual N leaching of location (coarse sand > loamy sand > sandy loam) and catch crops (without > with). Including a grass-clover green manure on 25% of the area did not increase N leaching compared with crop rotations without green manure. Also the application of animal manure did not influence N leaching, probably because even in the manured treatments the application rate was lower than crop demand. The results identify management of crop and soil during autumn as the main determinant of N leaching. Nitrate leaching was lowest for a catch crop soil cover during autumn and winter (avg. 20 kg N ha -1), a soil cover of weeds/volunteers had on avg. 30 kg N ha -1, and the largest N leaching losses were found after stubble cultivation (avg. 55 kg N ha -1). The N leaching losses increased with increasing number of autumn soil cultivations.
  • Authors:
    • Altieri, M. A.
    • Lana, M. A.
    • Bittencourt, H. V.
    • Kieling, A. S.
    • Comin, J. J.
    • Lovato, P. E.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 8
  • Year: 2011
  • Summary: In Santa Catarina, southern Brazil, family farmers modified the conventional no-till system by flattening cover crop mixtures on the soil surface as a strategy to reduce soil erosion and lower fluctuations in soil moisture and temperature, improve soil quality, and enhance weed suppression and crop performance. During 2007 and 2008, we conducted three experiments aimed at understanding the processes and mechanisms at play in successful organic conservation tillage systems (OCT), especially the underpinnings of ecological weed suppression, a key advantage of OCT systems over conventional no-till systems. Our results, as well as farmers observations, suggest that cover crops can enhance weed suppression and hence crop productivity through physical interference and allelopathy and also a host of effects on soil quality, fertility, and soil moisture that we did not measure. Results from the three trials indicate that the best cover crop mixture should include a significant proportion of rye, vetch, and fodder radish as these mixtures produce large biomass, and are readily killed by rolling forming a thick mulch sufficient to provide effective weed control in the subsequent vegetable crop.
  • Authors:
    • Chen, G.
    • Weil, R. R.
  • Source: Soil & Tillage Research
  • Volume: 117
  • Year: 2011
  • Summary: The yield of rainfed crops is commonly limited by the availability of soil water during the summer growing season. Channels produced by cover crop roots in fall/winter when soils are relatively moist may facilitate the penetration of compacted soils by subsequent crop roots in summer when soils are relatively dry and hard. Our objective was to determine the effects of fall cover crops on maize (Zea mays) growth and soil water status under three levels (high, medium, and no) of imposed traffic compaction. The study was conducted on coastal plain soils (fine-loamy Typic/Aquic hapludults and siliceous, Psammentic hapludults) in the mid-Atlantic region of the United States from 2006 to 2008. Cover crop treatments were FR (forage radish: Raphanus sativus var. longipinnatus, cv. 'Daikon'), rapeseed (Brassica napus, cv. 'Essex'), rye (cereal rye: Secale cereale L, cv. 'Wheeler') and NCC (no cover crop). Maize under high compaction achieved more deep-roots following FR and rapeseed than following rye or NCC. However, maize had greater yield following all cover crops than NCC control regardless of compaction levels and soil texture. Compaction reduced maize yield only under the high compaction in the lightly textured soils. During 24 June-24 July 2008, soils at 15 and 50 cm depths were drier under no compaction than high compaction and drier following FR than other cover crop treatments. Our results suggest that FR benefited maize root penetration in compacted soils while rye provided the best availability of surface soil water; rapeseed tended to provide both benefits. However, as rapeseed is relatively difficult to kill in spring, a mixture of FR and rye cover crops might be most practical and beneficial for rainfed summer crops under no-till systems in regions with cool to temperate, humid climates.