This paper aims to point out the problems and solutions of soil fertility enhancement in Korean organic farming which does not harmonize with internationally recognized standard of organic agriculture such as Basic Standard of IFOAM, EU regulations, and guidelines of FAO/WHO codex alimentarius. The necessity of rotation, legume, green manure to enhance the soil fertility or organic farming system was discussed, and the reasons why salt accumulation including nitrate and phosphate in the rooted soil profiles was frequently occurred in Korean organic farmer's field also discussed. Soil testing for correct handling of organic fertilization was introduced to void the salt accumulation just applying the huge amount of organic fertilizer year to year to reach a maximum crop yield. In the conclusion it was suggested for Korean organic agriculture to make an effort to coincide it's regulation with internationally recognized standards for organic farming.

This experiments was carried out to find the effect of different organic farming types, the Duck-pasture plot, the Pond-snail pasture plot andd control of the conventionalculture plot farming on the yield and its components of paddy rice. The results obtained are summarized as follows. Plant height an Tillering were significantly increase in the Duck-pasture plot. Panicle number pr hill, NO. of grain per spike and 1,000grain weight were significantly increase in the conventional culture plot. Yield pre 10a were 574.13kg at pond-snail pasture plot, 576.81kg at Duck-pasture plot and 579.04kg at conventional culture plot. From these results, it seems that the organic farming are useful and pasture of the Duck, Pond-snail for depression of the weed occurrence or increase of yield per 10a is effective as the environmental perservation farming.

To reduce loss of nitrogen and generation of ammonia gas during composting, poultry manure and sawdust were mixed at the equivalent ratio and calcium chloride, fused superphosphate and vermiculite were added. Ammonia and sulfurous gas during composting, and NH4-N and NO3-N contents of composts were periodically measured. With the treatments of 0.5∼3% calcium chloride and 3% fused superphosphate, ammonia and sulfurous gas during composting significantly decreased, and especially generation of gases sharply reduced and a increase of calcium chlorde. Extractable NH4-N content in composts treasted with calcium chloride and fused superphosphate were high but extractable NO3-N markedly decreased. In conclusion, the results suggest that it is necessary the additon of 1∼3% calcium chloride or 3% fused superphosphate to reduce loss of nirogen and generation of offensive odor during composting of poultry manure mixed with sawdust.

An organic agriculture should be managed by mixed farming in farm unit as a closed recycling system. Due to restricted purchased of fertilizers from outside, organic farmer has to deal with limited amount of nutrient source in farm unit. Especially the supply of the essential nutrient, nitrogen, mostly depends on legumes fixing nitrogen optimizing the site-adapted crop rotation. Dynamics of humus and metabolic plant carbon and active soil carbon compartment in active and passive humuspool by rotation system was explained, and dynamics of potentially mineralizable nitrogen in organic nitrogen and biomass was discussed. It was also discussed comparison of ammonia emission, potential greenhouse effect, primary energy input, acidification potential, CO2 emission between organic and conventional farming, the nitrate-nitrogen dynamic in the soil profile by organic, integrated and conventional farming system. In conclusion, it was suggested for Korean Organic Agriculture that the importance of legumes and green manures in rotation system for increase/maintenance of soil ferfility, and was pointed out the need of investment for environment impact of Korean organic farming implement.