Dolomite application enhances CH4 uptake in an acidic soil

Abstract

Methane (CH4) is a potent greenhouse gas and agricultural soils are the main source of atmospheric CH4. Information regarding CH4 emission from acidic soils is limited in the literature. A laboratory study was conducted to examine CH4 emissions following dolomite application in an acidic paddy soil. Dolomite was applied to the acidic soil (Ultisol) under two levels of moisture and nitrogen (N) fertilizer in a factorial design. Dolomite was applied at the rates of 0, 1, and 2gkg−1 soil (D0, D1, and D2 respectively) under two moisture levels of 55% and 90% water-filled pore space (WFPS). Each treatment of dolomite under two moisture levels was further treated with 0 and 200mgNkg−1 soil. Soil moisture of 90% WFPS produced (p≤0.001) CH4 emissions while uptake was observed in 55% WFPS. Nitrogen fertilizer application significantly increased CH4 emissions in 90% WFPS while inhibited uptake in 55% WFPS. Maximum cumulative CH4 emission (1784.88μgCH4-Ckg−1) was observed under 90% WFPS in N fertilizer application without dolomite application. Application of dolomite decreased cumulative CH4 emissions by 39% in 90% WFPS, and enhanced CH4 uptake up to 15 times in 55% WFPS with D2 treatment in fertilizer treated soil. Results indicated that dolomite application has the potential to enhance the uptake and to decrease the emissions of CH4 in acidic soils.