An experiment was conducted to investigate the effect of organic manures on soil properties, yield and yield attributes of soybean. Application of cowdung, poultry manure, rice-straw, compost, recommended fertilizer and combination of organic manure showed a significant positive effect on soil organic carbon, total N, available P and exchangeable K. Cowdung and poultry manure treated plots showed maximum available P and exchangeable K. For soil organic C, combined organic manure showed the best performance. Combined organic manure also showed the best performance for total N in soil. The highest seed yield and yield attributing characters were also found from the treatment of combined organic manure followed by poultry manure and lowest seed yield was found from control treatment.

Key words: Soybean, yield, organic manuring, soil properties.

Soybean (Glysine max. L. Merril) is an important well recognized oil grain legume crop of the world. It contains higher amount of both oil and protein than any other legume crops. It is favorable for good soil health. Soil organic matter in this country has been depleted by 5-36% during the period 1967-95. Fertilizers are essential part of modern farming, with about 505 of the world’s production being attributed to fertilizer use. As excessive use of chemical fertilizer and pesticides has caused extensive pollution of soil, water and air that has adversely affected food safety and quality and has endangered human and animal health (Matsumoto, 1994). Conversion from commercial fertilizer (conventional farming) to organic farming causes changes in the soil other than the fertility effects that can affect plant growth (Drinkwater et al., 1995). In accordance of consideration, the present study was under taken to study the influenced organic farming on soil properties, and to compare between conventional farming and organic farming system on soybean production.