• Authors:
    • Topp, C.
    • Walker, R.
    • Rees, R.
    • Edwards, A.
    • Baddeley, J.
    • Watson, C.
  • Source: Organic Agriculture
  • Volume: 1
  • Issue: 3
  • Year: 2011
  • Summary: The ability to maintain crop yield and quality in systems based on nitrogen (N) fixed by legumes rather than from synthetic N fertilisers is fundamental to the long-term viability of organic farming. This paper reports crop yield and nitrogen uptake parameters for the first spring oat crop after grass/clover ley in organically managed ley/arable rotations to indicate the amount of fertility built-up during the ley period. The trial site, at Tulloch in North East Scotland, underwent two complete cycles of 6-year ley/arable rotations with different lengths of grazed ley (3 or 4 years). Trials were sufficiently replicated so that each course of the rotation was present in every year. The rotation containing 3 years of ley was also compared with a similar rotation at a nearby site (Woodside) with lower rainfall and soil fertility over one and a half rotational cycles. Grain yields were consistently higher at Tulloch (5.1 tha -1 compared with 4.5 tha -1 at Woodside) and were unaffected by the length of ley. However, grain N percentage was higher following the 4-year ley (1.38% compared with 1.30% following the 3-year ley). While yields were maintained between the first and second cycles of all the rotations, grain N percentage declined. Annual grain yields of the organically grown oats at Tulloch were not significantly different from National List/Recommended List yields in NE Scotland for oats receiving 100 kg N ha -1. Results suggest that these particular rotation designs were suitable for maintaining acceptable grain yields under organic management conditions.
  • 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:
    • José-María, L.
    • Sans, F. X.
  • Source: Weed Research
  • Volume: 51
  • Issue: 6
  • Year: 2011
  • Summary: Weed seedbanks are a reserve of weed diversity and can contribute to the prediction of future weed problems in arable fields. Managing seedbanks should therefore help in optimising biodiversity and controlling weed infestations. This study assessed the effects of management system (organic vs. conventional) and landscape complexity on seedbank size and species richness at the edges and centres of Mediterranean dryland cereal fields and examines the relationship between specific management practices and seedbanks. Field edges and organic fields had more species-rich, denser seedbanks than field centres and conventional fields, and landscape complexity had a limited effect on arable seedbanks. Accordingly, the promotion of low-intensity farming practices regardless of landscape complexity, especially at field edges, would be an effective measure for conservation purposes in Mediterranean agroecosystems. Nevertheless, the high seed density of organic seedbanks reveals the need for more effective seedbank management. The analysis of the effects of specific management practices highlights the importance of cleaning crop seeds properly to reduce seedbank size and using complex rotations, especially as this tends to conserve species richness while reducing seed abundance.
  • Authors:
    • Sharief, A. E.
    • Badawi, M. A.
    • Attia, A. N.
    • Kandil, A. A.
    • Abido, W. A. E.
  • Source: Journal of Applied Sciences Research
  • Volume: 7
  • Issue: March
  • Year: 2011
  • Summary: Two field experiments were conducted at the Experimental Station, Faculty of Agriculture, Mansoura University, Egypt during 2007 and 2008 seasons. The objectives of this investigation is aimed to study the effect of water tension treatments, organic and inorganic fertilizer combinations and their interactions on quality, storability and chemical analysis of potato Spunta cultivar. Each irrigation treatments were conducted in a separate experiment. Every separate experiment laid-out in randomized complete block design with four replicates. Results indicated that highest averages of tuber length and diameter, nitrogen content in foliage and protein content in tubers were recorded with irrigation at irrigation at 26cb (5360.17 m 3 water/ha) i.e. 54.1% from field capacity in both seasons. Application of 60% mineral nitrogen fertilizer (238 Kg N/ha) plus 40% organic chicken manure (158 Kg N/ha) produced the highest averages of tuber length, tuber diameter, nitrogen content in foliage and protein content in tubers in both seasons. Adding 80% mineral nitrogen fertilizer (317 Kg N/ha) plus 20% organic chicken manure (79 Kg N/ha) recorded the highest averages of dry matter content after storage in Newalla & refrigerator. Results indicated that irrigation at 34cb (3449.62 m 3 water/ha) i.e. 45.8% from field capacity and adding 20% mineral nitrogen fertilizer (79 Kg N/ha) plus 80% organic chicken manure (317 Kg N/ha) produced the maximum values of dry matter content. It could be accomplished that irrigation at 26cb (5360.17 m 3 water/ha) i.e. 54.1% from field capacity as well as application of 60% mineral nitrogen fertilizer (238 Kg N/ha) plus 40% organic chicken manure (158 Kg N/ha) maximized averages of tuber length, diameter, nitrogen content in plant foliage and protein content in tubers.
  • 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:
    • Bojarszczuk, J.
    • Staniak, M.
    • Harasim, J.
  • Source: Journal of Research and Applications in Agricultural Engineering
  • Volume: 56
  • Issue: 3
  • Year: 2011
  • Summary: The aim of the field experiment carried out in 2007-2009 was to evaluate the yielding of pasture mixtures cultivated in organic farming. The study was conducted at the Institute of Soil Science and Plant Cultivation - Agricultural Experimental Station Grabow (Mazowia province). In the scheme of the experiment, the first factor was a dose of natural fertilization and the second factor was a percentage of legume seeds. Three doses of organic fertilization were applied as: 5, 10 and 15 t manure per 1 ha. The percentage of legumes seeds (white clover, red clover, bastard clover) in mixture was: 20, 35, 50%, the rest: Italian ryegrass, perennial ryegrass (2n), perennial ryegrass (4n), meadow bluegrass, red fescue, meadow fescue, cocksfoot, timothy. Mixtures were utilized in two ways of utilization: mown-grazed and grazed-mown system. The study showed that the highest total dry matter yields gave mixtures with 20% percentage of legume seeds in sowing, but significant differences were observed in the second year of utilization, in total yields. Differentiated organic fertilization had significant influence on dry matter yields. Increased dose of organic fertilization caused an increase of mixture yield. The combination, where legumes were sown in 20% and dose of organic fertilization was 15 t.ha -1 gave the highest dry matter yield. Differentiation of total protein yield between tested mixtures depended on organic fertilization dose. In mown-grazed utilization system, the highest total protein yields was obtained in mixtures fertilized with the dose of 15 t.ha -1 and in grazedmown utilization system - with the dose of 10 and 15 t.ha -1.
  • Authors:
    • Costa, M. S. S. de M.
    • Pivetta, L. A.
    • Steiner, F.
    • Costa, L. A. de M.
    • Castoldi, G.
    • Gobbi, F. C.
  • Source: Revista Brasileira de Ciencias Agrarias
  • Volume: 6
  • Issue: 4
  • Year: 2011
  • Summary: Crop systems and fertilization sources can affect the chemical properties of the soil and, consequently, its fertility. With the aim of evaluating the effect of such management practices, soil samples collected at 0.0-0.10; 0.10-0.20; and 0.20-0.40 m in depth were collected and analyzed in the second year of an experiment installed in 2006 in a Rhodic Hapludox under no-till farming, located in the Agronomic Experimental Station of UNIOESTE, in the city of Marechal Candido Rondon, Parana, Brazil. The experiment consisted of two crop systems (with and without rotation of cover crops) and three fertilization sources (mineral, organic and mineral+organic). The organic and mineral+organic fertilizations consisted of the application of animal manure alone and animal manure mixed with mineral fertilizer, respectively. The values of pH, exchangeable potassium (K +) and cation exchange capacity (CEC) were not affected by the different crop systems, related to the application of different fertilization sources. However, they did influence the organic matter contents (OM), potential acidity (H ++Al 3+), exchangeable aluminum (Al 3+), phosphorus (P), calcium (Ca 2+), magnesium (Mg 2+), and the bases sum and saturation (V%). The organic and mineral+organic fertilizations, with animal manure promoted the highest increase in soil Ca and Mg.
  • Authors:
    • Dawson, J. C.
    • Murphy, K. M.
    • Huggins, D. R.
    • Jones, S. S.
  • Source: Organic Agriculture
  • Volume: 1
  • Issue: 2
  • Year: 2011
  • Summary: There is growing interest in breeding crop cultivars specifically for organic agriculture, based on recognized differences in environmental conditions and management in organic systems compared to conventional systems, and especially due to environmental heterogeneity among and within individual organic systems. There is a need to develop effective strategies for improving crop performance in organic systems through plant breeding. This study evaluated 12 diverse winter wheat breeding lines chosen from conventional and organic breeding nurseries, six historic varieties, and an experimental perennial wheat population under organic management in the Inland Pacific Northwest region of the USA. A randomized complete block design with three replications in two locations over 2 years was used. Based on an analysis of variance, significant genetic differences and crossover interactions across years were found for grain yield, grain percent nitrogen, grain total nitrogen, and aboveground biomass. There were no main effects of locations or location-by-genotype effects for these traits. Based on comparisons among these breeding lines, it appears that there is a possibility of selecting for performance across a limited ecological zone as top-yielding lines were the same in both locations. However, individual entries may have variable performance across years within a single location so selection for stability of performance over years is also necessary. Using an analysis of direct measures of grain yield and grain %N in each location-year combination and overall, we identified breeding lines with relatively high yield, acceptable grain protein, and stable performance over all four location-year combinations. The use of indirect measures or index selection to simultaneously select for grain yield and protein did not appear to be more effective than direct selection based on yield and grain %N measured under organic management.
  • Authors:
    • Duboc, O.
    • Zehetner, F.
    • Gerzabek, M. H.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 6
  • Year: 2011
  • Summary: The increase in crop production brought by the green revolution in India is now shadowed by new challenges related to soil degradation (e.g., erosion, decline of soil organic matter content, salinization) and scarcity of water resources. The present work particularly discusses the contribution of no-till and organic farming, which are increasingly being adopted in India, to meet the increasing food demand in a sustainable way. Under no-till, erosion is reduced to rates close to those found in natural ecosystems, provided enough mulch is retained at the surface which is usually not the case in India, because of competing uses, for example, fodder, fuel, construction material, and also crop residue burning for land preparation. No-till should therefore not be considered separately from complementary measures, aiming at retaining mulch on the soil surface. Efficient recycling of organic material needs to be implemented concomitantly with diversifying fodder and fuel sources which requires enhancing the multifunctionality of farming systems. These prerequisites make it difficult for farmers to adopt no-till, particularly the poorer ones for whom experimentation with new techniques often involve unbearable financial risks. Organic farming apprehends the farm as an organism, and is thus a good option to improve sustainability as introduced above, by e.g., closing nutrient cycling. However, organic farming typically implies tillage for weed control (no chemical herbicides). "Natural farming," as promoted by Fukuoka (197834. Fukuoka, M. 1978. The one-straw revolution: an introduction to natural farming, Rodale Press. View all references) combines no-till with organic farming. An overview of available literature on Indian experiences with "natural farming," most of it originating from unconventional sources (i.e., reports available on Internet, but no peer reviewed literature) indicates that crop yields can compare well with the highest yields in a particular region. Increased productivity and environmental benefits are also often mentioned. The limited accuracy of these sources makes it necessary to pursue further investigations, and we conclude with propositions for future work in this context. This should start with a rigorous assessment of existing " natural farming" systems regarding their productivity and environmental benefits, in order to demonstrate its potential before starting projects that promote the system for broader adoption.
  • Authors:
    • Fasinmirin, J. T.
    • Reichert, J. M.
  • Source: Soil & Tillage Research
  • Volume: 113
  • Issue: 1
  • Year: 2011
  • Summary: Cassava ( Manihot esculenta crantz) is often cultivated on tilled plots, traditionally on mounds and ridges with the use of hand hoes or tractor driven implements. These two conditions alter the soil structural parameters and most times increase the vulnerability of soil to erosion or compaction as a result of frequent machine movement under the conventional tillage system. A review of the effects of tillage systems on soil bulk density, total porosity and penetration resistance was conducted to investigate the effectiveness of soil conservation for the optimum production of cassava in the tropics. Tillage treatments under review were: conventional tillage (CT), no-till (NT), minimum tillage (MT) and soil compaction (CP). Our review indicated that the bulk density (BD) in plots under CT was not significantly different ( p<0.05) from the value of BD in plots under minimum tillage (MT) within the 0-5 cm soil layer, but was highest in soils under compaction due to traffic passes of heavy duty equipment. Soils under no-till were characterized with lowest bulk density within the 0-5 cm layer, but gradually increased in BD within the 10-20 cm soil layer, which offers the soil some structural stability. However, the difference in bulk densities between plots under NT and CP treatments were highly significant at p<0.05, with CP plots having the highest bulk density within the 0-30 cm soil layer. Total porosity was highest in soils under conventional tillage (CT) comparatively with other tillage systems. Organic matter accumulation in NT treatment resulted to higher total porosity compared with other systems except CT at the surface soil (0-5 cm) but with reduced porosity at the sub-surface soil. Total porosity was least in plots under traffic passes (compacted plots). Statistically, there were no significant differences in total porosity among plots under conventional tillage with mulch residues, conventional tillage without mulch residues and minimum tillage with mouldboard at the p<0.05. However, plots under minimum tillage without mouldboard had lower total porosity. Penetration resistance was higher in NT plots when compared with plots under CT system, except from compacted plots (CP), which offered highest resistance to penetration. A long term experiment showed that cassava root yield was highest under NT with mulch residues, with or without fertilizer application. The reviewed work further confirmed that cassava can be grown successfully under no-till (NT) to give the optimum growth and yield required of the crop, while conserving the soil physical properties.