摘要
This study investigates the effects of conserved tills on the fluxes of carbon dioxide(CO_(2))and soil organic carbon(SOC)from a rain-fed-paddy plot in Assam(North-eastern state of India).Two paddy plots identical in soil properties,developed to cultivate rice(Sali,grown in low-lying areas of Assam),were adjacent to each other to follow a conventional agricultural practice in one and conservation in the other.Two chambers(1 m×0.6 m×0.4 m)were placed in both the plots to collect runoff for analyzing CO_(2) concentrations.The results of the both practices have been inter-compared.For conservation plot,the SOC was high in the range from 3.17+0.01 kg m^(−2) to 20.42+0.56 kg m^(−2) and the CO_(2) emission was less,i.e.97.30+7.11 mg m^(−2) h^(-1) as compared to 189.65+4.37 mg m^(−2) h^(-1) of the conventional plot.Low tillage practiced for the conservation plot facilitated higher porosity(50.11+8.40%to 88.87+3.59%)and greater water retention(47.47+1.15%to 101.37+1.63%)in the soil.The results indicate that more tillage exposed the soil to atmospheric oxygen more,which leads to excess mineralization of organic carbon and emissions of CO_(2) as in the conventional plot.
