549 | Page ICECS-EN-408-813 Prospects and problems of organic farming and its environmental impacts Leila Jahanban 1 and Mohammadreza Davari 2 1 M.Sc. of Soil Science, Payame Noor University (Shazand Unit); leilajahanban@yahoo.com 2 Ph.D. of Agroecology, Payame Noor University (Arak Unit); mrdavari@gmail.com Abstract Organic agriculture is a unique production management system which promotes and enhances agroecosystem health, including biodiversity, biological cycle and soil biological activity, and this is accomplished by using on-farm agronomic, biological and mechanical methods in exclusion off all synthetic off-farm inputs. Organic farming is the best choice we can make for our environment, animals and our own health. It aims to produce food while establishing an ecological balance to prevent soil fertility or pest problems. Soil building practices such as crop rotations, inter-cropping, symbiotic associations, cover crops, organic fertilizers and minimum tillage are central to organic practices. These encourage soil fauna and flora, improving soil formation and structure and creating more stable systems. In turn, nutrient and energy cycling is increased and the retentive abilities of the soil for nutrients and water are enhanced, compensating for the non-use of mineral fertilizers. Well managed organic systems with better nutrient retentive abilities, greatly reduce the risk of groundwater pollution. Organic agriculture reduces non-renewable energy use by decreasing agrochemical needs. Organic agriculture contributes to mitigating the greenhouse effect and global warming through its ability to sequester carbon in the soil. The impact of organic agriculture on natural resources favors interactions within the agro-ecosystem those are vital for both agricultural production and nature conservation. Ecological services derived include soil forming and conditioning, soil stabilization, waste recycling, carbon sequestration, nutrients cycling, predation, pollination and habitats. Keywords: Organic agriculture, problems, prospects and environmental issues Introduction Organic agriculture is holistic production management systems which promotes and enhances agro ecosystem health, including biodiversity, biological cycles, and soil biological activity. Organic production systems are based on specific and precise standards of production which aim at achieving optimal agro-ecosystems which are socially, ecologically and economically sustainable. Terms such as "biological" and "ecological" are also used in an effort to describe the organic system more clearly. Requirements for organically produced foods differ from those for other agricultural products in that production procedures are an intrinsic part of the identification and labeling of, and claim for, such products. Organic production systems avoid or minimize the use of synthetic fertilizers, pesticides and antibiotics. They instead rely on biological pest control and specific soil management techniques, such as crop rotations including grass/clover leys, winter break and catch crops and/or green manures, crop residue management and manuring, to control plant diseases and pests, maintain soil fertility and improve physical soil properties [2]. Organic farming practices aim to increase sustainability by reducing pesticide residues on crops (Figure 1: human health), improving biodiversity in the soil (productivity, environment), avoiding leaching losses and runoff (environment), and reducing soil erosion by enhancing soil structure (productivity, environment) [5]. It has to be stressed, however, that alternative farming systems are not sustainable per definitionem. Incorporation of leys, legumes or animal manures, for example, can lead to a nitrate surplus and cause leaching or runoff and weed control by intensive land cultivation can result in soil compaction [1 & 19]. There is an extensive range of reviews evaluating soil fertility, crop production and environmental issues (biodiversity, nitrate and pesticide leaching, gaseous emissions, etc.) on organic and conventional farms in New Zealand and overseas [7, 12 & 21]. Most authors have come to broadly similar conclusions, as follows: - There is inconsistent evidence regarding the impact of organic farming on soil structure. Scientists reported positive effects on soil aggregate stability [6 & 7]. - Organic farming practices are reported to have a positive effect on the soil organic matter, mainly because of high organic matter inputs to the soil (e.g. animal or green manures, crop residue), which is beneficial for soil microbial biomass and activity. However, the addition of organic material is a farming