• Authors:
    • Santos, H.
    • Fontaneli, R.
    • Spera, S.
    • Dreon, G.
  • Source: Revista Brasileira de Ciencias Agrarias
  • Volume: 6
  • Issue: 3
  • Year: 2011
  • Summary: Soil fertility attributes were evaluated on a typical dystrophic Red Latosol (typic Haplorthox) located in Passo Fundo, State of Rio Grande do Sul, Brazil, twelve years after the establishment (1993, 2000, 2002 and 2005) of five integrated crop/livestock farming production systems: system I - wheat/soybean, white oat/soybean, and common vetch/corn; system II - wheat/soybean, white oat/soybean, and grazed black oat+grazed common vetch/corn; system III - perennial cool season pastures (fescue+white clover+red clover+birds foot trefoil); system IV - perennial warm season pastures (bahiagrass+black oat+rye grass+white clover+red clover+birds foot trefoil); and system V - alfalfa as hay crop. The plots under systems III, IV, and V returned to system I after the summer of 1996. However, in the summer of 2002, in the systems III, IV and V, what used to be crop returned to pasture and what used to be pasture returned to crop. An acidification process occurred in all layers by the lowest pH values and higher concentration and saturation by Al, in comparison to the soil in 1998. The organic matter level and the P, K and Al levels increased between 1998 to 2002, in all sampled layers, while the opposite occurred with pH, Ca and Mg contents.
  • Authors:
    • Silveira, F. de M.
    • Silva, E. D. B. da
    • Pauletti, V.
    • Favaretto, N.
    • Vezzani, F. M.
    • Dieckow, J.
  • Source: Revista Brasileira de Ciencia do Solo
  • Volume: 35
  • Issue: 5
  • Year: 2011
  • Summary: The use of manure in agricultural system is a possibility to dispose of the waste generated in animal production, but improper use can cause environmental problems. The general objective of this study was to evaluate carbon and nitrogen concentrations and losses in runoff in four doses of liquid dairy manure (0, 60, 120, 180 m 3 ha -1 yr -1) applied to a silt clay loam Oxisol with 13% slope, in no-till with soybean, oat, corn, and wheat in crop rotation. The runoff was collected for two years and seven months in 60 L containers after every rain with runoff from at least one plot. Soluble nutrients were analyzed in runoff samples filtered through a 0.45 m membrane and total nutrients in unfiltered samples. The application of liquid dairy manure reduced the losses of organic carbon and nitrogen, with positive consequences for water quality. However, higher rates tended to increase the concentrations of these elements and, consequently, reduce water quality. The weighted average concentrations of nitrate were below the limit allowed by Brazilian legislation, but ammonium exceeded the threshold values, indicating the need of control measures to prevent the runoff from reaching the water bodies, even in no-tillage systems. It should be pointed out that these data were obtained under low potential polluting conditions, i.e, on 13% slope, low rainfall and with a minimum interval of ten days between manure application and rainfall. Further studies should also evaluate nitrate leaching.
  • Authors:
    • Flaten, D. N.
    • Entz, M. H.
    • Vaisman, I.
    • Gulden, R. H.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: The blade roller offers new opportunities to reduce tillage, especially in organic farming. The objective of the study was to reduce tillage in the green manure phase of a green manure-wheat ( Triticum aestivum L.) rotation by substituting tillage with blade rolling. A pea ( Pisum sativum L.) and oat ( Avena sativa L.) green manure was used for two site-years at Carman, MB, while a pea monocrop was used for one site-year at Oxbow, SK. At pea flowering, the green manure was terminated by rolling, tilling, or a combination of the two. Ammonia emissions were greater in the no-till compared with the tilled green manure system, though total ammonia losses were low (<13 kg ha -1). Replacing tillage with rolling reduced soil nitrate N in autumn after green manure by 56 to 88 kg ha -1 in the 0- to 60-cm soil depth. Reduced green manure tillage did not affect wheat establishment but delayed plant development in some instances. Fewer weeds were often observed in wheat in the no-till compared with tilled plots. Total N supply in the green manure-wheat system was reduced in the no-till system compared to the tilled only system at two out of three site-years by an average of 44%. While reduced N supply in the reduced tillage system coincided with reduced wheat yield and protein, it was concluded that factors other than N also were involved. Using the blade roller instead of tillage in the green manure year provides soil conservation benefits and facilitates wheat production the following year.
  • Authors:
    • Torres, M. O.
    • Varennes, A. de
  • Source: Soil Use and Management
  • Volume: 27
  • Issue: 1
  • Year: 2011
  • Summary: Soil changes induced by crop rotations and soil management need to be quantified to clarify their impact on yield and soil quality. The objective of this study was to investigate the effect of continuous oat ( Avena sativa L.) and a lupin ( Lupinus albus L.)-oat rotation with and without tillage on soil enzymes, crop biomass and other soil properties In year 1, oat and lupin were grown in undisturbed plots or in plots subjected to disc tillage. Crop residues were incorporated before oat was sown in year 2 in the disc-tilled plots or remained on the soil surface of untilled plots. Soil samples were collected regularly and analysed for pH, organic C, Kjeldahl-N, mineral N, extractable P, and the enzyme activities of beta-glucosidase, cellulases, acid phosphatase, proteases, urease, and culturable bacteria and fungi. The main crop and tillage effects on soil parameters were: beta-glucosidase activity was greater after lupin than after oat, and the opposite was true for the number of culturable fungi. Organic carbon, phosphatase, cellulase and protease were greater in tilled soil than in the absence of tillage. Associations between variables that were stable over the 2 yr were those for mineral N and urease activity, cellulase activity and pH, and that of phosphatase activity and organic C. Our results contrast with most of the previous information on the effect of tillage on soil enzymes, where the activities were reported to be unchanged or decreased following tillage. This difference may be related to the small organic C content of the soil and to the fact that it was under fallow prior to the start of the experiment. In consequence, incorporation of residues would provide new sources of labile organic C for soil microbes, and result in increased enzymatic activity. The results obtained suggest that in coarse-textured soils poor in organic matter, tillage with residue conservation after a period of fallow rapidly improves several soil characteristics and should be carried out even if it were to be followed by a no-till system in the following years. This should be taken into consideration by land managers and technical advisers.
  • Authors:
    • European Food Safety Authority
  • Source: EFSA Journal
  • Volume: 9
  • Issue: 1
  • Year: 2011
  • Summary: Difenoconazole is one of the 84 substances of the third stage part B of the review programme covered by Commission Regulation (EC) No 1490/2002,3 as amended by Commission Regulation (EC) No 1095/2007.4 Difenoconazole was included in Annex I to Directive 91/414/EEC on 1 January 2009 pursuant to Article 11b of the Regulation (EC) No 1490/2002, as amended by Commission Regulation (EC) No 1095/2007 (hereinafter referred to as "the Regulation"). Sweden, being the designated rapporteur Member State submitted a draft assessment report (DAR) on difenoconazole in accordance with the provisions of Article 10(1) of the Regulation, which was received by the EFSA on 22 December 2006. A peer review was initiated by EFSA on 6 March 2007 by dispatching the DAR for consultation of the Member States and the notifier Syngenta Ltd. Following consideration of the comments received on the DAR, EFSA conducted a focused peer review the active substance difenoconazole, its, physicochemical and technical properties, mammalian toxicology, residues, environmental fate and behaviour, ecotoxicology, and risk assessment on the environment. The conclusions laid down in this report were reached on the basis of the evaluation of the representative uses of difenoconazole as a fungicide on pome fruit, carrot, wheat, barley, triticale, rye and oats as proposed by the notifier.
  • Authors:
    • Zekaite, V.
    • Deveikyte, I.
    • Kadziuliene, Z.
    • Sarunaite, L.
    • Maiksteniene, S.
    • Arlauskiene, A.
    • Cesnuleviciene, R.
  • Source: ZEMDIRBYSTE-AGRICULTURE
  • Volume: 98
  • Issue: 4
  • Year: 2011
  • Summary: Intercropping of cereals and grain legumes is a technology intended to enhance biodiversity in organic agroecosystems, increase and stabilize yields and make better use of plant growth resources. The experiments were designed to investigate the intercrops' yield advantage in different soil, climate and plant competition conditions in organic farming. Field trials were carried out during 2007-2010 at the Lithuanian Institute of Agriculture at three different soil sites: on a loamy Endocalcari-Epihypogleyic Cambisol ( CMg-p-w-can) (Dotnuva), on a clay loam Endocalcari-Endohypogleyic Cambisol ( CMg-n-w-can) (Joniskelis) and on a sandy loam Hapli-Albic Luvisol ( LVe-ha) (Perloja). Pea ( Pisum sativum L. (Partim)) and spring wheat ( Triticum aestivum L. emend. Fiori et Paol.), spring barley ( Hordeum vulgare L.), oat ( Avena sativa L.) and spring triticale (* Triticosecale Wittm.) were sown as intercrops (50:50 - a relative proportion of grain legume and spring cereal seeds) or as a sole crop. The result showed that weather and soil conditions during plant emerge determined the optimal productive density and created a basis for competition between the intercrop components. Spring cereals were dominant due to higher aggressivity index and competition rate compared with peas. Under various soils' conditions the aggressivity of cereals increased with increasing density of pea. In productive soils (Dotnuva, Joniskelis), the highest competitive and suppressive power in the intercrops was exhibited by oats, in low productivity soils (Perloja) - the dominant species varied. Under the conditions of various soils, the production of pea intercrop with oats or barley was directly affected by cereals, while pea intercropped with wheat or triticale by the two components of the intercrop. In terms of grain yield, intercrops ranked as follows: pea/oats > pea/wheat, pea/triticale > pea/barley. In loamy soil (Dotnuva), these regularities were less consistent, therefore the advantages of intercrops' yield over sole crops' yield were negligible when the relative yield total (RYT) was >1.0, except for the pea intercropped with barley. In Joniskelis and Perloja, the relative yield total showed greater and more stable yield advantages of intercrops, except pea intercropped with triticale. The efficiency of intercrops stood out even more vividly in the treatments managed under organic cropping system for a longer period of time.
  • Authors:
    • Meersmans, J.
    • Poesen, J.
    • Baets, S.
    • Serlet, L.
  • Source: Catena
  • Volume: 85
  • Issue: 3
  • Year: 2011
  • Summary: Cover crops are a very effective erosion control and environmental conservation technique. When cover crops freeze at the beginning of the winter period, the above-ground biomass becomes less effective in protecting the soil from water erosion, but roots can still play an important role in improving soil strength. However, information on root properties of common cover crops growing in temperate climates (e.g. Sinapis alba (white mustard), Phacelia tanacetifoli (phacelia), Lolium perenne (ryegrass), Avena sativa (oats), Secale cereale (rye), Raphanus sativus subsp. oleiferus (fodder radish)) is very scarce. Therefore, root density distribution with soil depth and the erosion-reducing effect of these cover crops during concentrated flow erosion were assessed by conducting root auger measurements and controlled concentrated flow experiments with 0.1 m topsoil samples. The results indicate that root density of the studied cover crops ranges between 1.02 for phacelia and 2.95 kg m -3 for ryegrass. Cover crops with thick roots (e.g. white mustard and fodder radish) are less effective than cover crops with fine-branched roots (e.g. ryegrass and rye) in preventing soil losses by concentrated flow erosion. Moreover, after frost, the erosion-reducing potential of phacelia and oats roots decreased. Amoeba diagrams, taking into account both below-ground and above-ground plant characteristics, identified ryegrass, rye, oats and white mustard as the most suitable species for controlling concentrated flow erosion.
  • Authors:
    • Pelissari, A.
    • Moraes, A.
    • Balbinot Junior, A.
    • Veiga, M.
    • Dieckow, J.
  • Source: Revista Brasileira de Agrociencia
  • Volume: 17
  • Issue: 1
  • Year: 2011
  • Summary: The objective of this study was to evaluate the effect of winter soil use on reminiscent straw on the soil, physical characteristic in superficial soil layer and maize performance cultivated in succession. One experiment was carried out in three places in the North Plateau of Santa Catarina State, Brazil, during 2006/07 crop season. Five alternatives of soil use in the winter were investigated: (1) multicropping with black oat+ryegrass+vetch+arrow leaf clover without grazing and nitrogen fertilization (multicropping cover); (2) the same multicropping, with grazing and nitrogen fertilization, 100 kg ha -1 of N (pasture with N); (3) the same multicropping, with grazing and without nitrogen fertilization (pasture without N); (4) oil seed radish, without grazing and nitrogen fertilization (oil seed radish); and (5) natural vegetation, without grazing and nitrogen fertilization (fallow). Higher straw dry mass was verified in multicropping cover. The winter annual pasture in crop-livestock system, cover crops and fallow did not affect the bulk density in 0,02 to 0,07 m of soil layer and maize performance in succession.
  • Authors:
    • Brennan, E. B.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 5
  • Year: 2011
  • Summary: Winter cover crops can add soil organic matter, improve nutrient cycling, and suppress weeds in organic vegetable systems. A 2-yr study was conducted on organic farms in Salinas and Hollister, CA, to evaluate the effect of seeding rate (SR) and planting arrangement on cover crop density, ground cover, and cover crop and weed dry matter (DM) with a mixed cover crop. The mix contained legumes (35% Vicia faba L., bell bean; 15% Vicia dasycarpa Ten., woolypod vetch; 15% Vicia benghalensis L., purple vetch; and 25% Pisum sativum L., pea) and 10% oat (Avena sativa L.) by seed weight. Three SRs (112, 224, and 336 kg ha(-1)) and two planting arrangements (one-way versus grid pattern) were evaluated. Planting arrangement had no effect on the variables measured. When weeds were abundant, weed DM declined linearly with increasing SR from approximately 300 kg ha(-1) at the low SR to <100 kg ha(-1) at the high SR. Increasing SR increased oat and legume DM early in the season, but did not affect final cover crop DM that ranged from 7 to 12 Mg ha(-1). Year affected final cover crop DM production at both sites. The legume DM portion of the total cover crop declined through the season but varied between sites and year, probably due to soil and climatic differences. Higher SRs may be cost effective because weed control is expensive and cover crop seed is a relatively small component of cover cropping costs in this region.
  • Authors:
    • Montfort, F.
    • Faloya, V.
    • Schlaunich, E.
    • Aubree, N.
    • Breton, D.
  • Source: 4eme Conference Internationale sur les Methodes Alternatives en Protection des Cultures.
  • Year: 2011
  • Summary: To study the interest and the limits of the insertion of various cover crop with biofumigation potential in a crop succession, three trials, one in Aquitaine (40), one in Normandy (50) and one in Rheu (35) were performed on two important soilborne diseases of carrot: cavity-spot due to Pythium sulcatum or the brown rot disease due to Rhizoctonia solani. Intercrop plants were cultivated then crushed and incorporated in the soil one month before carrot crop. In the three trials, the effect of the mustard Brassica juncea on the incidence and the severity of the diseases is studied and compared with bare soil. In the Normandy trial, two other cover crops are also studied: oat and rye crop. In Le Rheu trial, regular observations allow to compare the development of cavity-spot over time after insertion then incorporation of a mustard crop or after a bare soil. The results are presented; the technical feasibility and the impact of method on disease development are discussed.