Effect of sulphur oxidizing microorganisms on nutrient availability in soil under soybean.

摘要

Sulphur oxidizing microorganisms showed synergistic effect on nutrient availability under soybean cropped soil. The composite culture of microorganisms viz., Thiobacillus thiooxidans, Aspergillus terreus, A. niger, Trichoderma harzianum and Myrothecium cinctum was found to be the most effective in increasing available nitrogen, phosphorus, potash and sulphur in soil. Among the cultures, Thiobacillus thiooxidans showed superior results over all the fungal cultures. The available nitrogen, phosphorus, potash and sulphur were increased from 119.82 to 127.89, 15.47 to 19.31, 140.05 to 145.08 kg ha-1 and 19.70 to 39.65 mg kg-1 respectively. The sulphur treatment alone also increased nutrients in soil significantly over control. The sulphur uptake by soybean crop increased from 249 to 367 mg 100 g-1 dry weight of plant and soil pH reduced from 7.6 to 7.0 during crop growth period due to inoculation of sulphur oxidizing microorganisms with sulphur application. The combined inoculation of sulphur oxidizing microorganisms with sulphur can be adopted as a mean to attain high nutrient availability in soil under soybean.