Sulphide Production in Some Typical Rice Soils of Assam

Eleven representative soil samples were collected from the waterlogged rice fields of different agro-climatic regions of Assam. The soils were incubated with different rates of lime, ammonium sulphate and single superphosphate. Lime significantly increased all the sulphide fractions except the acid soluble one. Superphosphate significantly increased water soluble and total sulphide fractions only. The ammonium sulphate significantly increased all the sulphide fractions in soils. The combined effect of lime, ammonium sulphate and superphosphate resulted in highest H₂S and water soluble sulphide production in soils.

A highly significant positive correlation was observed between total sulphide production and sulphate reducing bacterial population.