Effect of sulfate and urea on methane production in paddy soil under incubated soil condition

Abstract

Methane is one of important greenhouse gases emitted from submerged paddy soil under anaerobic condition. The objective of the present experiment was to study the influence of sulfate and urea on methane production
in paddy soil. Four rates of sulfate (0, 50, 100 and 210 kg SO42- ha-1) were set up by using ammonium phosphate (16-20-0, 42 % sulfate) with the amount of N, P2O5 and K2O for each treatment being balanced by using urea, rock phosphate and potassium chloride. In addition, soil without urea application was prepared. All soils were incubated in bottles for 21 days in oxygen-free nitrogen ambient. Result showed that there is a linear relationship with negative correlation between methane production in soil and sulfate contents. The soil without urea applied produced more methane production than did those applied with this fertilizer with urea. The result also illustrated that methane production decreased with increasing rates of sulfate in soil. Moreover, urea alone decreased methane production in soils regardless of all quantities of sulfate. Further trial under field condition should be performed.