Short-term diurnal and temporal measurement of methane emission in relation to organic carbon, phosphate and sulphate content of two rice fields of central Gujarat, India

摘要

Methane emission from two rice fields of Lambhvel village, Anand district, Central Gujarat, India, was measured for whole cultivation period during pre-summer season. Along with the methane emission, soil chemistry of the two rice fields (Organic Carbon, PO 4 ?2 and SO 4 ?2 ) was determined. The methane emission ranged from 0.10 to 0.56 mg/m2 per h, having maximum emission during noon period (11 a.m. to 1 p.m.) of the day at the Rice field-1. Besides, at rice field-2, the methane emission ranged between 0.15 and 0.94 mg/m2 per h, having maximum peak during same period (11 a.m. to 1 p.m.) of the day. The results of the current investigation confirm that the methane emission vary substantially between two rice fields, and suggest that soil chemistry and water level might control the methane emission in both the rice fields and suppressed by the phosphate and sulphate concentrations. The greater methane emission was declined with the age of rice plantation. Correlation analysis, ANOVA and F test showed that the methane emission from both the sites has positive correlation with organic carbon and negative correlation with sulfate and phosphate content of the soil and the details of these reasons will be discussed in this paper.