Carbon Sequestration in Soil Cooperated with Organic Composts and Bio-Char during Corn (Zea mays) Cultivation

Background: The objective of this study was to estimate the carbon sequestration in soils cooperated with organic composts and bio-char during corn cultivation. Methods and Results: For the experiment, the soil texture used in this study was clay loam, and application rates of chemical fertilizer and bio-char were 230-107-190 kg·ha-1 (N-P2O5-K2O) as recommended amount after soil test and 0.2% to soil weight. The soil samples were periodically taken at every 15-day intervals during the experimental periods. The treatments consisted of cow compost, pig compost, swine digestate from aerobic digestion system, and their bio-char cooperation. For estimating soil C sequestration, it is determined by the net balance between carbon inputs and outputs during corn cultivation periods. For the experimental results, it found that applications of aerobic swine digestate, cow compost, and pig compost could sequester C by 38.9%, 82.2% and 19.7% in soil, respectively, when bio-char from rice hulls was cooperated with soil. For plant responses, application of bio-char in the corn field for carbon sequestration was not occurred the damage of corn growth. Conclusion: When bio-char from rice hulls was cooperated with soil, applications of aerobic swine digestate, cow compost, and pig compost could sequester C by 38.9%, 82.2% and 19.7% in soil, respectively. Therefore, addition of bio-char with organic composts could have a potential soil C sequestration in agricultural practices.