• Authors:
    • Scopel, E.
    • Triomphe, B.
    • Tourdonnet, S. de
    • de Tourdonnet, S.
  • Source: Proceedings of a symposium on Innovation and Sustainable Development in Agriculture and Food, Montpellier, France, 28 June to 1st July 2010
  • Year: 2010
  • Summary: No-tillage techniques and conservation agriculture (CA), based on minimal soil disturbance, the maintenance of plant cover and a diversification of rotations and intercropping, are developing rapidly in both the North and South. The emergence of these techniques often involves an original process of innovation based on continuous and adaptive learning within innovative socio-technical networks, which overturn the traditionally linear process of innovation design and transfer. Changes in the functioning of the agrosystem associated with CA are likely to supply ecosystem services, but the difficult implementation of these techniques may decrease the performance of the agrosystem, in particular by increasing dependence on pesticides. The general objective of the PEPITES project is to generate knowledge concerning ecological processes, technical and social innovation processes and their interactions, for the evaluation and design of more sustainable technical and support systems. We are working towards this objective by constructing an interdisciplinary approach combining biophysical sciences, cropping system and production system agronomy and the sociology of innovation, in partnership with professionals in four study terrains: conventional field crops in France, organic farming in France and small-scale family farms in Brazil and Madagascar. After one year of operation, we present here the progress made towards answering the questions posed in this project, in terms of the positioning of research with respect to two key questions: first concerning the construction of an interdisciplinary approach in partnership to assist the innovation process and the generation of knowledge, and second the construction of an approach for comparing terrains in the North and South.
  • Authors:
    • Boydston, R. A.
  • Source: American Journal of Potato Research
  • Volume: 87
  • Issue: 5
  • Year: 2010
  • Summary: Managing weeds without herbicides requires an integration of methods and strategies and a change in how weeds are perceived. Weeds should be managed in a holistic, intentional and proactive manner. Understanding the interactions between the cropping system and the weed community and managing the cropping system to prevent and discourage weeds and maintain a low weed seedbank is necessary for successful weed management in organic systems. Cultural practices, including a well-planned crop rotation, planting cover crops, sanitation practices, and optimum row spacing and timing of planting are important aspects of managing weeds in organic systems. Multiple, well timed shallow cultivations or flaming can eliminate many early season weeds. Once emerged, many crops are fast growing and produce a canopy able to suppress weeds. New technologies for detecting crop rows and weeds coupled with precision cultivation, flaming, and application of nonselective organic herbicides are being developed and hold promise to reduce the need for hand weeding.
  • Authors:
    • Munier-Jolain, N. M.
    • Kurstjens, D. A. G.
    • Colbach, N.
    • Dalbies, A.
    • Dore, T.
  • Source: European Journal of Agronomy
  • Volume: 32
  • Issue: 3
  • Year: 2010
  • Summary: Because of environmental and health safety issues. it is necessary to develop strategies that do not rely on herbicides to manage weeds. Introducing temporary grassland into annual crop rotations and mechanical weeding are the two main features that are frequently used in integrated and organic cropping systems for this purpose. To evaluate the contribution of these two factors in interaction with other cropping system components and environmental conditions, the present study updated an existing biophysical model (i.e. ALOMYSYS) that quantifies the effects of cropping system oil weed dynamics. Based oil previous experiments, new sub-models were built to describe the effects on plant survival and growth reduction of mechanical weeding resulting from weed seedling uprooting and covering by soil, and those of grassland mowing resulting from tiller destruction. Additional modifications described the effect of the multiyear crop canopy of grassland on weed survival, growth, development and seed return to the soil. The improved model was used to evaluate the weed dynamics over 27 years in the conventional herbicide-based cropping system most frequently observed in farm Surveys (i.e. oilseed rape/winter wheat/winter barley rotation with Superficial tillage) and then to test prospective non-chemical scenarios. Preliminary simulations tested a large range of mechanical weeding and mowing strategies, varying operation frequencies, dates and, in the case of mechanical weeding, characteristics (i.e. tool, working depth, tractor speed). For mechanical weeding soon after sowing, harrowing was better than hoeing for controlling weed seed production. The later the operation, the more efficient the hoeing and the less efficient the harrowing. Tractor speed had little influence. Increasing tilling depth increased plant mortality but increased weed seed production because of additional seed germination triggering by the weeding tool. Decreasing the interrow width for hoeing was nefarious for weed control. The best combinations were triple hoeing in oilseed tape and sextuple harrowing in cereals. The best mowing strategy was mowing thrice, every 4-6 weeks, starting in mid-May. The best individual options were combined, simulated over 27 years and compared to the herbicide-based reference system. If herbicide applications were replaced solely by mechanical weeding, blackgrass infestation Could not be satisfactorily controlled. If a three-year lucerne was introduced into the rotation, weed infestations were divided by ten. Replacing chisel by mouldboard ploughing before winter wheat reduced weed infestations at short, medium and long term to a level comparable to the herbicide-based reference system. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Robertson, G. P.
    • Thelen, K. D.
    • Corbin, A. T.
    • Leep, R. H.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 6
  • Year: 2010
  • Summary: Agronomic management during the 3-yr transition period to organic certification influences soil quality and the weed seedbank. We studied two cropping systems during the transition period and the first certified organic season. A 4-yr rotation of corn, soybean, wheat/alfalfa, corn (C-S-W/A-C) [Zea mays L., Glycine max (L.) Merr., Triticum aestivum L., Medicago sativa L.], produced under a more complex management that included manure and cover crop residue, was compared to a perennial based corn, alfalfa, alfalfa, corn (C-A-A-C) rotation. We compared soil aggregate size distribution and bulk density after Year 1 and on completion of the transition period. Weed seedbank populations were quantified through two seasons in the greenhouse. Weed surface density and aboveground weed biomass were quantified in the field. Over the course of the study, the percentage of large soil macroaggregates (> 2000 mu m size class) had 2.7 and 3.4-fold increase for the C-A-A-C and C-S-W/A-C treatments, respectively. The C-S-W/A-C system generated a 4.5-fold increase in aggregates of this class when wheat that was interseeded with alfalfa was harvested as forage. Bulk density decreased 14 and 6% for the C-S-W/A-C and the C-A-A-C systems, respectively. There was a 60 to nearly 300% increase in total weed seeds germinated in the greenhouse for the C-S-W/A-C system. This same system had a 60 to more than 500% decreased weed seedbank density in the field. We conclude from this study that either strategy can improve soil quality while the weed seedbank was better managed in the more complicated C-S-W/A-C system.
  • Authors:
    • Hirata, T.
    • Hoshino, Y.
    • Hane, S.
    • Hajime, A.
  • Source: Horticulture Environment and Biotechnology
  • Volume: 50
  • Issue: 4
  • Year: 2009
  • Summary: More than 70% of fresh tomato is produced in plastic high tunnel or greenhouse and much fertilizer and agricultural chemicals have been applied for tomato production. Cover crop is one of the important tools for sustainable agro-production because of improving soil properties. Effect of cover cropping on soil properties and tomato production in plastic high tunnel was examined in Sapporo, Japan, snow cover region. Plastic high tunnel was set before snow-melting, late in March, 2007. Two cover crops, legume (hairy vetch; Vicia villosa R.) and non legume (wild oat; Avena sterigosa L.), were planted each alone or mix-planted in the plot (0.8 m in width and 3.5 m in length) early in April. Seeding density in mono-culture was 5 kg/10a in hairy vetch and 10 kg/10a in wild oat. For bi-culture, density was 3.5 kg/10a in hairy vetch and 5 kg/10a in wild oat. Above ground biomass (dry weight) was shown 445 kg/10a in hairy vetch and 982 kg/10a in wild oat late in May. However, in mix-culture, it was 190 kg/10a in hairy vetch and 602 kg/10a in wild oat. Cover crops were killed for residue mulch just before tomato planting. Seedlings of tomato 'Momotaro' were planted in the plots covered with cover crop residue and 12 kg/10a N fertilizer application (12 kg N/10a) and bare plot with 12 kg/10a or 24 kg/10a N fertilizer (24 kg N/10a) application. Nitrate concentration of the petiole sap in the leaf just below the first fruit cluster was higher in the tomatoes grown in bare plot with 24 kg N/10a and in hairy vetch mulch with 12 kg N/10a at 40 days after transplanting. Large yield was shown in bare plot with 24 kg N/10a (7.9 t/10a) and in hairy vetch plot with 12 kg N/10a (7.8 t/10a). The yield in bare plot with 12 kg N/10a and Mix plot with 12 kg N/10a was 6.9 t/10a. The yield in wild oat plot with 12 kg N/10a was the smallest (6.1 t/10a). Soil carbon in the plots with cover crop mulch became higher than that of bare plots after tomato production. It will be possible to obtain current yield and to increase soil carbon in cover cropping with reduction of N fertilizer. This technique will lead the organically grown system in plastic high tunnel production.
  • Authors:
    • Ngouajio, M.
    • Kaya, E.
    • Isik, D.
    • Mennan, H.
  • Source: Crop Protection
  • Volume: 28
  • Issue: 4
  • Year: 2009
  • Summary: Weed control is a major constraint for organic production around the world. Field studies were conducted in pepper ( Capsicum annuum L.) from 2004 to 2006 at the Black Sea Agricultural Research Institute experimental field in Turkey to determine the weed suppressive effects of winter cover crops. Treatments consisted of ryegrass ( Lolium multiflorum L.), oat ( Avena sativa L.), rye ( Secale cereale L.), wheat ( Triticum aestivum L.), gelemen clover ( Trifolium meneghinianum Clem.), Egyptian clover ( Trifolium alexsandrinum L.), common vetch ( Vicia sativa L.), hairy vetch ( Vicia villosa Roth.) and a bare fallow with no cover crop. Weed density and total weed dry biomass were assessed at 14, 28, and 56 days after incorporation to quantify effects of cover crops during a subsequent pepper crop. Cover crop establishment was similar in both growing seasons and individual species produced in the range of 1800-3500 kg/ha biomass. Ryegrass produced the greatest biomass compared with other species. Weed dry biomass production just before cover crop incorporation varied with year and cover crop species. Hairy vetch, ryegrass, oat and common vetch were the most competitive cover crops based on total weed dry biomass. Hairy vetch was the most promising cover crop and reduced weed density by 73% and 70% at 28 and 56 DAI, respectively. Pepper yields were higher following all cover crops except Egyptian clover. The highest yield was obtained from hairy vetch plots in both years. This research indicates that cover crops such as hairy vetch, ryegrass, oat and common vetch could be used in integrated weed management programs to reduce weed infestation in organic pepper.
  • Authors:
    • Liatukas, Z.
    • Leistrumaite, A.
    • Razbadauskiene, K.
  • Source: Agronomy Research
  • Volume: 7
  • Issue: Special Issue
  • Year: 2009
  • Summary: Investigation on 12 spring barley and 7 oat genotypes under organic growing system during 2007-2008 revealed that mean yield of oats was 3.3 t ha -1, whereas barley yielded on average 2.3 t ha -1. Also, oats were found to be more resistant to leaf diseases. Oats were severely infected by leaf rust in 2007, but the disease did not correlate ( r=-0.17) with yield. The majority of barley genotypes were infected with powdery mildew in both years and with leaf spotting diseases in 2007. Leaf spotting diseases negatively influenced ( r=-0.53*) yield. Oats possessing higher vegetative growth rate, higher plant height, large and prostrate leaves, and larger stems were superior to barley by canopy traits during the growing season.
  • Authors:
    • Migliorini, P.
    • Mazzoncini, M.
    • Bigongiali, F.
    • Antichi, D.
    • Lenzi, A.
    • Tesi, R.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 24
  • Issue: 2
  • Year: 2009
  • Summary: When animal husbandry is not included in organic farming systems, green manure may be crucial to preserve or increase soil organic matter content and to ensure an adequate N supply to crops. Different species, both legumes and nonlegumes, may be used as cover crops. The present research was carried out to investigate the effect of different green manure crops [oats and barley mixture ( Avena sativa L. and Hordeum vulgare L.), rye ( Secale cereale L.), brown mustard ( Brassica juncea L.), flax ( Linum usitatissimum L.), pigeon bean ( Vicia faba L. var. minor)] on the production of the following tomato crop. A field trial was conducted for two cropping seasons (2003-2004 and 2004-2005) in a commercial organic farm. The yield of tomato crop was positively affected by pigeon bean, although statistically significant differences in comparison with the other treatments were observed only in 2004-2005, when the experiment was conducted in a less fertile soil. This was probably due mainly to the effect of the pigeon bean cover crop on N availability. In fact, this species, in spite of a lower biomass production than the other cover crops considered in the study, provided the highest N supply and a more evident increase of soil N-NO 3. Also, cover crop efficiency, evaluated using the N recovery index, reached higher values in pigeon bean, especially in the second year. The quality of tomato fruits was little influenced by the preceding cover crops. Nevertheless, when tomato followed pigeon bean, fruits showed a lower firmness compared to other cover crops, and in the second year this was associated with a higher fruit N content.
  • Authors:
    • Logsdon, G.
  • Source: Small-scale grain raising
  • Issue: Ed.2
  • Year: 2009
  • Summary: This book (12 chapters) discusses the basics of the organic farming and processing of whole grains (specifically maize, wheat, sorghum, oats, dry beans, rye and barley, buckwheat and millet, rice, some uncommon grains, and legumes) for home gardeners and small-scale farmers. Topics covered include planting; pest, weed and disease management; harvesting; and processing, storing and using whole grains. Some recipes are also included.
  • Authors:
    • Isk, D.
    • Ngouajio, M.
    • Mennan, H.
    • Kaya, E.
  • Source: PHYTOPARASITICA
  • Volume: 37
  • Issue: 4
  • Year: 2009
  • Summary: Weed control is a major concern for organic farmers around the world and non-chemical weed control methods are now the subject of many investigations. Field studies were conducted in tomato ( Solanum lycopersicum L.) from 2004 to 2006 at the Black Sea Agricultural Research Institute experiment field to determine the weed suppressive effects of winter cover crops. Treatments consisted of ryegrass ( Lolium multiflorum L.), oat ( Avena sativa L.), rye ( Secale cereale L.), wheat ( Triticum aestivum L.), gelemen clover ( Trifolium meneghinianum Clem.), Egyptian clover ( Trifolium alexandrinum L.), common vetch ( Vicia sativa L.), hairy vetch ( Vicia villosa Roth.) and a control with no cover crop. Treatments were arranged in a randomized complete block design with four replications. To determine the weed suppressive effects of the cover crops, weed density and total weed dry biomass were assessed at 14, 28, and 56 days after termination (DAT) of the cover crops from all plots using a 50*50 cm quadrat placed randomly in each plot. After cover crop kill and incorporation into soil, tomato seedlings variety 'H2274' were transplanted. Broadleaved weed species were the most prominent species in both years. Total weed biomass measured just prior to cover crop incorporation into the soil was significantly lower in S. cereale plots than in the others. The number of weed species was lowest at 14 DAT and later increased at 28 and 56 DAT, and subsequently remained constant during harvest. This research indicates that cover crops such as L. multiflorum, S. cereale, V. sativa and V. villosa could be used in integrated weed management programs to manage some weeds in the early growth stages of organic tomato.