Showing papers on "Organic farming published in 2006"

Diversity of flower-visiting bees in cereal fields: effects of farming system, landscape composition and regional context

Abstract: 1. Agri-environment schemes promote organic farming in an attempt to reduce the negative effects of agricultural intensification on farmland biodiversity and ecosystem services such as pollination. Farming system, landscape context and regional differences may all influence biodiversity, but their relative impact and possible interactions have been little explored. 2. The study was performed in three regions (150 km apart, 400-500 km(2) per region) differing in land use intensity. Within each region, seven pairs of conventionally and organically cultivated wheat fields (mean size 4 ha, 42 study fields) were selected to encompass a gradient from heterogeneous to homogeneous landscapes within a 1-km radius around each field. 3. Farming system had the greatest influence on biodiversity. Higher bee diversity, flower cover and diversity of flowering plants were recorded in organic compared with conventional fields. Bee diversity was related both to flower cover and diversity of flowering plants, suggesting plant-mediated effects of the farming system. 4. Differences in bee diversity between organic and conventional fields increased with the proportion of arable crops in the surrounding landscape, indicating that processes at the landscape level modified the effectiveness of organic farming in promoting biodiversity. Similar patterns for flower cover and diversity of flowering plants suggested that landscape effects on bee diversity were mainly resource-mediated. After statistically removing the variance explained by flower parameters, residual bee diversity increased with increasing landscape heterogeneity. 5. Bee diversity differed between the three regions, but the effects of farming systems and landscape context were independent of regional differences. 6. Synthesis and applications. Bee diversity in wheat fields was mainly influenced by farming system, but an understanding of local bee diversity needs to incorporate both landscape and regional perspectives. The consistency of the results in three regions provides a reliable basis for management decisions. Agri-environment schemes that promote organic farming in homogeneous landscapes where there are few remaining flower-rich habitats could have the highest relative impact. However, while organic farming could help to sustain pollination services by generalist bees in agricultural landscapes, other measures are required to conserve more specialized bee species in semi-natural habitats.

Soil microbial biomass and activity in organic tomato farming systems: Effects of organic inputs and straw mulching.

Abstract: Organic farming is rapidly expanding worldwide. Plant growth in organic systems greatly depends on the functions performed by soil microbes, particularly in nutrient supply. However, the linkages between soil microbes and nutrient availability in organically managed soils are not well understood. We conducted a long-term field experiment to examine microbial biomass and activity, and nutrient availability under four management regimes with different organic inputs. The experiment was initiated in 1997 by employing different practices of organic farming in a coastal sandy soil in Clinton, NC, USA. Organic practices were designed by applying organic substrates with different C and N availability, either in the presence or absence of wheat–straw mulch. The organic substrates used included composted cotton gin trash (CGT), animal manure (AM) and rye/vetch green manure (RV). A commercial synthetic fertilizer (SF) was used as a conventional control. Results obtained in both 2001 and 2002 showed that microbial biomass and microbial activity were generally higher in organically than conventionally managed soils with CGT being most effective. The CGT additions increased soil microbial biomass C and activity by 103–151% and 88–170% over a period of two years, respectively, leading to a 182–285% increase in potentially mineralizable N, compared to the SF control. Straw mulching further enhanced microbial biomass, activity, and potential N availability by 42, 64, and 30%, respectively, relative to non-mulched soils, likely via improving C and water availability for soil microbes. The findings that microbial properties and N availability for plants differed under different organic input regimes suggest the need for effective residue managements in organic tomato farming systems.

Reduced nitrate leaching and enhanced denitrifier activity and efficiency in organically fertilized soils.

Abstract: Conventional agriculture has improved in crop yield but at large costs to the environment, particularly off-site pollution from mineral N fertilizers. In response to environmental concerns, organic agriculture has become an increasingly popular option. One component of organic agriculture that remains in question is whether it can reduce agricultural N losses to groundwater and the atmosphere relative to conventional agriculture. Here we report reduced N pollution from organic and integrated farming systems compared with a conventional farming system. We evaluated differences in denitrification potential and a suite of other soil biological and chemical properties in soil samples taken from organic, integrated, and conventional treatments in an experimental apple orchard. Organically farmed soils exhibited higher potential denitrification rates, greater denitrification efficiency, higher organic matter, and greater microbial activity than conventionally farmed soils. The observed differences in denitrifier function were then assessed under field conditions after fertilization. N2O emissions were not significantly different among treatments; however, N2 emissions were highest in organic plots. Annual nitrate leaching was 4.4–5.6 times higher in conventional plots than in organic plots, with the integrated plots in between. This study demonstrates that organic and integrated fertilization practices support more active and efficient denitrifier communities, shift the balance of N2 emissions and nitrate losses, and reduce environmentally damaging nitrate losses. Although this study specifically examines a perennial orchard system, the ecological and biogeochemical processes we evaluated are present in all agroecosystems, and the reductions in nitrate loss in this study could also be achievable in other cropping systems.

The effect of organic farming on butterfly diversity depends on landscape context

Abstract: The recent dramatic decline in farmland biodiversity is often attributed to agricultural intensification and structural changes in the agricultural landscape. One suggested farm practice seen to benefit biodiversity and reverse declines is organic farming. Because organic farming is viewed as a more sustainable form of agriculture it is currently subsidized by European agri-environment schemes. However, the efficiency of agri-environment schemes to preserve biodiversity has recently been questioned, partly because their uptake has been highest in extensively farmed more heterogeneous landscapes. We investigated the effect of farming practice on butterfly species richness and abundance along cereal field headlands and margins on 12 matched pairs of organic and conventional farms in contrasting landscapes (homogeneous and heterogeneous landscape diversity). Both organic farming and landscape heterogeneity significantly increased butterfly species richness and abundance. There was also a significant interaction between farming practice and landscape heterogeneity, because organic farming only significantly increased butterfly species richness and abundance in homogeneous rather than heterogeneous landscapes. An analysis of the distribution of organic farming in Sweden in relation to productivity of the arable land (yield of spring barley, kg ha(-1)) indicated that the distribution of organic farms was skewed towards extensively farmed agricultural areas. Synthesis and applications. The species richness and abundance of butterflies can be enhanced by actions aimed at both promoting organic farming and increasing landscape heterogeneity. However, the beneficial effect of organic farming was only evident in intensively farmed homogeneous landscapes. Currently, the majority of organic arable land in Sweden is located in heterogeneous landscapes where changing the type of farming practice adds little to the existing biodiversity. We therefore propose that the interaction between landscape heterogeneity and farming practice must be considered when promoting farmland biodiversity, for example in Europe by developing context-based agri-environment schemes to increase the amount of organic farming in intensively farmed landscapes. We also propose that in homogeneous agricultural landscapes, organic farming could be used as a more efficient tool to restore landscape heterogeneity if the creation of semi-natural landscape elements was mandatory in the regulations associated with organic agri-environment schemes. (Less)

A history of organic farming: Transitions from Sir Albert Howard's War in the Soil to USDA National Organic Program

Abstract: The organic farming concept developed in the period prior to 1940 and was pioneered by Sir Albert Howard (1873–1947). Howard, born and educated in England, directed agricultural research centers in India (1905–1931) before permanently returning to England. His years of agricultural research experiences and observations gradually evolved into a philosophy and concept of organic farming that he espoused in several books. Howard's thinking on soil fertility and the need to effectively recycle waste materials, including sewage sludge, onto farmland was reinforced by F.H. King's book, Farmers of Forty Centuries. Howard developed a system of composting that became widely adopted. Howard's concept of soil fertility centered on building soil humus with an emphasis on how soil life was connected to the health of crops, livestock, and mankind. Howard argued that crop and animal health was a birthright and that the correct method of dealing with a pathogen was not to destroy the pathogen but to see what could be learned from it or to ‘make use of it for tuning up agricultural practice’. The system of agriculture advocated by Howard was coined ‘organic’ by Walter Northbourne to refer to a system ‘having a complex but necessary interrelationship of parts, similar to that in living things’. Lady Eve Balfour compared organic and non-organic farming and helped to popularize organic farming with the publication of The Living Soil. Jerome Rodale, a publisher and an early convert to organic farming, was instrumental in the diffusion and popularization of organic concepts in the US. Both Howard and Rodale saw organic and non-organic agriculture as a conflict between two different visions of what agriculture should become as they engaged in a war of words with the agricultural establishment. A productive dialogue failed to occur between the organic community and traditional agricultural scientists for several decades. Organic agriculture gained significant recognition and attention in 1980, marked by the USDA publication Report and Recommendations on Organic Farming. The passage of the Federal Organic Foods Production Act in 1990 began the era of accommodation for organic farming in the USA, followed by another milestone with official labeling as USDA Certified Organic in 2002. Organic agriculture will likely continue to evolve in response to ongoing social, environmental, and philosophical concerns of the organic movement.

Social sustainability, farm labor, and organic agriculture: Findings from an exploratory analysis

Abstract: Much of the attention by social scientists to the rapidly growing organic agriculture sector focuses on the benefits it provides to consumers (in the form of pesticide-free foods) and to farmers (in the form of price premiums). By contrast, there has been little discussion or research about the implications of the boom in organic agriculture for farmworkers on organic farms. In this paper, we ask the question: From the perspective of organic farmers, does “certified organic” agriculture encompass a commitment to “sustainability” that prioritizes social goals? Specifically, we aim to broaden our understanding of the relationship between social sustainability and organic agriculture by drawing attention to issues affecting farmworkers, whose labor and contribution tends to elude most discussions of organic agriculture. We present findings from a survey of organic farmers in California about the possible incorporation of social standards into organic certification criteria. Our findings suggest that, at best, lukewarm support for social certification within organic agriculture exists among certified organic farmers in California. They also question expectations that organic agriculture necessarily fosters social or even economic sustainability for most of the farmers and farmworkers involved. However, we also find exceptions to the patterns evidenced in our survey. In-depth interviews with select organic farmers demonstrate that there are individuals whose practices are atypical and demonstrate that, under some circumstances, an organic production system can be at once environmentally, economically, and socially sustainable.

Information Acquisition and Adoption of Organic Farming Practices

Abstract: This study offers an empirical framework for analyzing farmers' joint decisions to adopt organic farming practices and to seek technical (i.e., farming) information from various sources. To that end, a trivariate ordered probit model is specified and implemented in the case of organic land conversion in Crete, Greece. Findings suggest that the decisions of information acquisition and organic land conversion are indeed correlated, and different farming information sources play a complementary role. Structural policies improving the farmer's allocative ability are found to play an important role in encouraging organic farming adoption.

Nutrient Use Efficiencies and Leaching of Organic and Conventional Cropping Systems in Sweden

Abstract: Organic farming has been proposed as a means of reducing leaching and improving the use efficiency of plant nutrients in agriculture. In such systems, nutrient inputs originate from various organic sources or from naturally occurring minerals with low solubility. In this study, measurements of leaching and crop uptake of N, P, and K and determinations of mineral N in soil were conducted in tile-drained plots during a 6-yr period in two organic crop rotations, one with and one without addition of animal manures. In the latter, N was provided by green manures. For comparison, two conventional systems in which mineral fertilizers and pesticides were used (one with cover crops) were also included. Leaching loads of N were smallest in the conventional system with cover crops, on average 25 kg N ha -1 yr -1 over the 6-yr period. The corresponding amounts in the other systems were 39 (organic with animal manure), 34 (organic without animal manure), and 38 (conventional) kg N ha -1 . Phosphorus-leaching loads were small overall in all systems (<0.25 kg ha -1 yr -1 ). Potassium-leaching loads reached on average 27 kg ha -1 yr -1 over the 6 yr in the conventional systems and 16 kg ha yr -1 in the organic systems. When N leaching was expressed as a percentage of total N removal during the 6-yr period (leaching plus harvested N with crops), it represented 59% in the organic system without animal manure, 33% in the conventional system, and 22% in the conventional system with cover crops. These results clearly suggest that N use efficiency is improved if inorganic N fertilizers are used rather than green manures, especially in combination with cover crops. The superior system from all considerations was the conventional system with a cover crop.

Competitive ability of wheat in conventional and organic management systems: A review of the literature

Abstract: Wheat (Triticum aestivum L.) is the world’s most widely grown crop, cultivated in over 115 nations. Organic agriculture, a production system based on reducing external inputs in order to promote ec...

A market road to sustainable agriculture? Ecological agriculture, green food and organic agriculture in China

Abstract: To the extent that free markets show little concern for the existence of externalities, they are unlikely to produce optimum outcomes with regard to the protection and enhancement of the natural environment. Accordingly, the increasing emphasis on markets to deliver development in China under Deng Xiaoping and his successors has the capacity to threaten the long-term environmental sustainability of that development. While there are good reasons to remain sceptical about the ability of market mechanisms to promote sustainable rural development in many respects, market reforms in China and the opening of the country to the outside world have nevertheless provided opportunities for farmers to engage in ecologically sensitive agriculture in the form of ‘green’ food and organic farming. Given that these forms of agriculture reduce farmers’ use of chemicals compared to conventional farming — chemicals which are costly to produce and environmentally degrading to use — they contribute to ensuring a more environmentally sustainable future for Chinese farming, post-WTO entry, whilst providing opportunities for farmers to enrich themselves at the same time: a ‘win–win’ state of affairs. This will remain the case, however, only so long as the state is prepared to create and reinforce appropriate institutional arrangements.

Challenges to Organic Potato Farming: Disease and Nutrient Management

Abstract: For organic potato producers the two main challenges are disease and nutrient management. Both factors are limited by regulations that on the one hand prohibit the use of chemical fertilisers, especially nitrogen and, on the other hand, most synthetic pesticides. Late blight, caused by Phytophthora infestans is commonly thought to be the factor most limiting yield. However, because there is no really effective fungicide available to control late blight, there are virtually no yield loss data available for organic farming conditions. In this paper the state of the art of organic potato management with respect to disease and nutrient management is summarised. In a second part, the interactive effects of N-availability in the soil, climatic conditions and late blight were studied in the presence and absence of copper fungicides from 2002–2004 for the mid-early main-crop potato cv. Nicola. From the experimental work it became clear that copper fungicides in most cases do slow down epidemics adding an average of 3 days to the growth duration. However, only 30% of the variation in yield could be attributed to disease reduction. A model including disease reduction, growth duration and temperature sum from planting until 60% disease severity was reached, and soil mineral N contents at 10 days after emergence could explain 75% of the observed variation in yield. However, the model failed when N-supply was extremely high. The implications of the results on the management of organic potatoes with respect to cultivar choice, nutrient and disease management are discussed. In conclusion, several points emerge from the results: In organic farming, yields are foremost limited by nutrient availability in spring and early summer. The effects of late blight on yields may often be overestimated and cannot be deducted from results in conventional farming because of the strong interaction with nutrient status. Resistance clearly remains the most important strategy against late blight in organic potato production. However, as important or even more important than resistance is the early development and bulking behaviour and the ability of a cultivar to make use of organic nutrients efficiently. In the absence of efficient organic pesticides it is possible to reduce blight pressure to a certain extent by arranging the crop in small narrow fields perpendicular to the main wind direction neighboured either by non-hosts or completely resistant potatoes.

Handbook of Sustainable Weed Management

Abstract: Weeds and Their Management: Rationale and Approaches, R.K. Kohli, D.R. Batish, and H.P. Singh Weed Management: A Basic Component of Modern Crop Production, R. Labrada Contributions to Weed Suppression from Cover Crops, M.L. Hoffman and E.E. Regnier Utilizing Brassica Cover Crops for Weed Suppression in Annual Cropping Systems, R.A. Boydston and K. Al-Khatib Grass-Legume Mixed Cover Crops for Weed Management N.R. Burgos, R.E. Talbert, and Y.I. Kuk Rye As a Weed Management Tool in Vegetable Cropping Systems, J.B. Masiunas A Rotation Design That Aids Annual Weed Management in a Semiarid Region, R.L. Anderson Examining Tillage and Crop Rotation Effects on Weed Populations in the Canadian Prairies, R.E. Blackshaw, A.G. Thomas, D.A. Derksen, J.R. Moyer, P.R. Watson, A. Legere, and G.C. Turnbull Potential of Allelopathy and Allelochemicals for Weed Management, D.R. Batish, H.P. Singh, R.K. Kohli, and G.P. Dawra Progress in Developing Weed-Suppressive Rice Cultivars for the Southern United States, D.R. Gealy and K.A. Moldenhauer The Ecology of Weed Seed Predation in Herbaceous Crop Systems, F.D. Menalled, M. Liebman, and K.A. Renner Mowing for Weed Management, W.W. Donald Herbicide Fate Under Conservation Tillage, Cover Crop, and Edge-of-Field Management Practices, M.A. Locke, R.M. Zablotowicz, and M.A. Weaver Strategies for Developing Bioherbicides for Sustainable Weed Management, S.M. Boyetchko and E.N. Rosskopf Developing Microbial Weed Control Products: Commercial, Biological, and Technological Considerations, K.L. Bailey and E.K. Mupondwa Implementation of Weed Biocontrol in Forest Vegetation Management for Conifer Production, S.F. Shamoun Characterization of Phytotoxins from Phytopathogenic Fungi and Their Potential Use As Herbicides in Integrated Crop Management, A. Evidente and M.A. Abouzeid Applications of Soil and Rhizosphere Microorganisms in Sustainable Weed Management, R.J. Kremer Herbicide-Resistant Crops and Weed Management, K.N. Reddy and C.H. Koger Strategies for Managing Herbicide-Resistant Weeds, H.J. Beckie and G.S. Gill Recent Advances in Parasitic Weed Research: An Overview, J.R. Qasem Management of Weeds in Pasture Systems, B.M. Sindel Integrated Turfgrass Weed Management, R.S. Chandran Approaches to Integrated Weed Management, D.D. Buhler Learning Groups for Implementation of Integrated Weed Management: Principles and Practical Guidelines, N. Jordan, H. Niemi, S. Simmons, R. Becker, J. Gunsolus, and S. White Index Reference Notes Included

Organic Production and Use of Alternative Crops

Abstract: INTRODUCTION What is Organic Agriculture? Organic Food Multifunctionality of Organic Agriculture Organic Crop Production Contribution of Organic Agriculture to the Conservation of Alternative Crops and their Utilization Development References CEREALS Spelt Einkorn Emmer Kamut Triticale Intermediate Wheatgrass References PSEUDOCEREALS (WITHOUT MILLETS) Buckwheat Quinoa Grain Amaranths Wild Rice References MILLETS Proso Millet Foxtail, Foxtail Millet Pearl Millet Finger Millet White Fonio Barnyard Millet Little Millet References ALTERNATIVE OIL PLANTS Oil (Seed) Pumpkins Camelina Safflower White Mustard (Garden) Poppy References ALTERNATIVE FIBER, ROOT, AND TUBER CROPS Industrial and Edible-Seed Hemp Flax Jerusalem Artichoke Sweet Potato References LEGUMES Chickpea Groundnut Soybean: Small Attention to the Important Crop Vigna: A Few Words about a Widely Spread Genus References SOME TRADITIONAL AND NEW KINDS OF FOOD FROM SOME ALTERNATIVE CROPS Homemade Food from Buckwheat Homemade Food from Amaranths Homemade Food from Millet References Index

Root growth and nitrogen uptake of carrot, early cabbage, onion and lettuce following a range of green manures

Abstract: An experiment was performed to study the significance of rooting depth of four vegetable crops on their utilization of green manure nitrogen (N). Rates of rooting depth development were estimated as approximately 0.2, 0.7, 1.2 and 1.2 mm day C)1 for onion, carrot, lettuce and cabbage, respectively. At harvest, onion and lettuce were found to be shallow-rooted with final rooting depths of only 0.3 and 0.6 m, respectively, whereas carrot and cabbage reached rooting depths of at least 1.1 m. The two deep-rooted vegetables increased their N uptake by 46, 24 and 7 kg N ha)1 when following winterhardy legumes, non-hardy legumes and rye, respectively; the equivalent responses by the two shallowrooted crops were 23, 9 and 15 kg N ha)1, respectively. Thus the deep-rooted crops used the legume N more efficiently but the shallow-rooted crops made better use of N left by the non-legume rye crop. These interactions between green manure type and vegetable crop N response are the result of the dual effects of the green manures: biological N fixation by the legumes, and the variable ability of the green manure crops to concentrate available N in the topsoil. Before shallow-rooted crops, the ability of rye to concentrate N in the topsoil may be as important as the N fixing ability of legumes.

Local and landscape factors in differently managed arable fields affect the insect herbivore community of a non-crop plant species

Abstract: Summary 1 The expansion of simplified ecosystems such as intensively managed annual crops plays a big part in driving the global biodiversity crisis. Field-scale diversification, for example leaving weeds to grow in crops, is one way in which diversity in agro-ecosystems can be restored. However, little is known about the determinants of the non-crop plant-based insect communities within arable fields at local and larger spatial scales, an essential component in extrapolating plant diversity benefits to higher trophic levels. 2 We investigated how diversification of agro-ecosystems at the field and landscape levels affects the insect community of the creeping thistle Cirsium arvense. Artificial plots of the host-plant were established in three regions of Germany in 48 paired organic (diverse, weeds not controlled with herbicides) and conventional (simplified, very low weed density and species richness) wheat fields across a gradient of landscape heterogeneity, from simple arable-dominated to heterogeneous, diverse landscapes. 3 Leaf-feeding herbivores were monitored directly, while stem-boring herbivores and their parasitoids were quantified by dissecting the stems of the thistles. Land-use types and naturally occurring thistle stands were mapped within a radius of 1 km around each thistle plot. 4 Herbivore species richness was enhanced by both organic farming and landscape heterogeneity but not by higher densities of thistles in the landscape. For most of the species, host-plant plots in organic fields were more likely to be colonized than those in the conventional fields. The enhancement of diversity in organic fields is probably the result of a slightly higher natural cover of the host-plant Cirsium arvense. 5 Synthesis and applications. Both diversification of landscape (fewer arable crops, more perennial habitats) and extensification through organic management are effective measures of enhancing arthropod diversity on weeds. The impact of field-scale agri-environment schemes on biodiversity should be supplemented by including landscape-scale diversification programmes to include a minimum level of perennial habitat cover. Biodiversity benefits of organic agriculture rely for a large part on non-crop plants. Weed populations should be allowed to coexist with the crop to maintain these benefits, which are threatened by more intensive ‘organic’ management, such as heavy mechanical weed control.

Animal health in organic livestock production systems : a review

Abstract: Organic livestock production is a means of food production with a large number of rules directed towards a high status of animal welfare, care for the environment, restricted use of medical drugs and the production of a healthy product without residues (pesticides or medical drugs). The intentions of organic livestock production have been formulated by the International Federation of Organic Agriculture Movements (IFOAM) and were further implemented by EU regulation 2092/91 in the year 2000. The consequences of these rules for the health of the animals were not yet fully anticipated at the time these regulations were made and it has become clear that in some cases the rules are not clear enough, thereby even hampering the development of the production system. In this review we shall discuss the implications of these rules for animal health, whereby we shall focus on pig, poultry and dairy production systems. Disease prevention in organic farming is based on the principles that an animal that is allowed to exhibit natural behaviour is not subject to stress, is fed optimal (organic) feed, and will have a higher ability to cope with infections than animals reared in a conventional way. Fewer medical treatments would thus be necessary and if an animal would become diseased, alternative treatments instead of conventional drugs should be preferred. Although homeopathy or phytotherapy are recommended according to prevailing regulations, not many organic farmers use this treatment regimen because of lack of scientific evidence of effectiveness. Important health problems in organic livestock farming are often related to the outdoor access area, exposing the animals to various viral, bacterial and parasitic infections some of which may only influence the animals’ own welfare whereas other ones may also endanger the health of conventional livestock (e.g. Avian Influenza) or pose a food safety (Campylobacter, Toxoplasma) problem to the consumer. Many preventive measures can be taken, such as using better animal breeds, optimized rearing conditions, pre- and probiotics, and addition of acids to the drinking water. In case of infectious disease, tight vaccination schedules may prevent serious outbreaks.

Adubação verde na produção orgânica de alface americana e repolho

Abstract: The exclusive use of organic compost in the production of organic vegetables has been found to be a costly practice due to the high volume of compost demanded to obtain commercial productions. Thus, one of the alternatives for complementary fertilization of vegetables is the use of green manure. The objective of this work was to evaluate three green manure species, used to complement the fertilization with organic compost, in relation to the nutrient contents in their biomass, and to productivity and agronomic traits of crisphead lettuce and cabbage. The experiment was carried out at the Olericulture Sector of the Federal University of Lavras (UFLA), in Lavras, Minas Gerais State, Brazil, from December 2001 to August 2002, in a soil classified as Udox. The experiment was arranged in a randomized block design in a factorial scheme (4x2) with three repetitions. The first factor was constituted by the green manure species: black-velvet bean (Stizolobium aterrimum), jack bean (Canavalia ensiformis), and sunnhep (Crotalaria juncea), plus a control treatment (weed and mineral fertilizers); and the second factor was constituted by the vegetable crops: crisphead lettuce and cabbage. Among the tested green manure species, sunnhep presented the best potential for extraction of N, P, K, Mg, B, Mn and Zn. In addition, sunnhep was more efficient than jack bean or black velvet bean in increasing the commercial weight of cabbage head. In relation to productivity, as for lettuce, green manuring plus organic compost did not differ from the control; while for the cabbage, these treatments had a performance statistically inferior. The use of green manure plus organic compost allowed to obtain commercial crisphead lettuce and cabbage heads with satisfactory weight for the market.

The impact of organic farming on food security in a regional and global perspective.

Abstract: The spread of organic and agro-ecological farming (OF) methods in developing countries has raised a debate whether a large scale adoption of OF will increase or decrease global food security. This will however depend on a number of socio-economic factors together with the relative yield levels of OF versus conventional farming systems. Relative yields again depend on a number of agro ecological factors and the characteristics of farming systems before conversion. In areas with intensive high-input agriculture, conversion to OF will most often lead to a reduction in crop yields per ha by 20-45 % in crop rotations integrated with leguminous forage crops. In many areas with low input agricultural systems farmers have little incentive or access to use chemical fertiliser and pesticides, and yields may increase when agro ecological principles are introduced. While present food production in theory is sufficient to cover the energy and protein needs of the global population there are still more than 740 million food insecure people, the majority of whom live in South Asia and Africa South of Sahara (SSA). This number will only decrease over the next 20 years if the present policies are changed. The food policy model IMPACT was used to project possible effects on food security of a large scale conversion to OF in Europe/North America (E/NA) and SSA. Results indicate that a conversion of approximately 50 % of E/NA agricultural area will have a 6-10 % impact on world prices on (non-meat) agricultural commodities under the assumptions of 35 % lower OF yields after conversion and 50 % higher yield growth rates compared with conventional crop yields. The indirect effect on food security in SSA would be very small up scaling experiences from case studies into scenarios for conversion of 50 % of agricultural area in SSA results in increased self-sufficiency and decreased net food import to the region. Given the assumption of higher relative yields in most organic crops compared with existing low input agriculture, there is potential for improving local food security in SSA if non-certified OF is supported by capacity building and research. More knowledge is needed, however, to confirm that these optimistic results of non-certified OF apply to large areas in SSA and other regions with low input agriculture.

Do the new organic producers differ from the ‘old guard’? Empirical results from Norwegian dairy farming

Abstract: Conventional farmers converting to organics have contributed to most of the rapid expansion of organic farming in recent years. The new organic farmers may differ from their more established colleagues, which may have implications for the development of the organic farming sector and its distinctiveness vis-a`-vis conventional production and marketing practices. The aim of this study was to explore Norwegian organic dairy farmers’ personal and farm production characteristics, farming goals, conversion motives, and attitudes to organic farming, grouped by year of conversion (three groups). A postal survey was undertaken among organic dairy farmers (n = 161). The results show that the newcomers (converted in 2000 or later) were less educated than the early entrants (the so-called ‘old guard’) who converted in 1995 or earlier. The frequency of activities like vegetable growing and poultry farming among the old guard was high. The late-entry organic herds were fed with more concentrates and had a higher milk production intensity, showed a higher incidence of veterinary treatments and less frequent use of alternative medicine than the herds of the two earlier converting groups. For all groups of farmers, the highest ranked farming goals were sustainable and environment-friendly farming and the production of high-quality food. Late entrants more often mentioned goals related to profit and leisure time. On average, the most frequently mentioned motives for conversion were food quality and professional challenges. The old guard was more strongly motivated by food quality and soil fertility/pollution issues than the others, whereas financial reasons (organic payments included) were relatively more important among the newcomers. All groups held very favorable views about the environmental qualities of organic farming methods, albeit with different strengths of beliefs. Even though trends towards more pragmatic and business-oriented farming were found, the majority of the newcomers were fairly committed.