Carbon dioxide emission and carbon sequestration potential in Alfisol

Mujiyo, Eko Hanudin, Jauhari Syamsiyah, Jaka Widada, Bambang Hendro Sunarminto

Abstract: Carbon dioxide (CO2) is one of the greenhouse gases, which also promotes global warming. It can be formed from the decomposition of organic matter like rice straw in the soil. The laboratory study was conducted to determine CO2 production and carbon (C) sequestration from fresh and wheathered rice straw applications on Alfisols. The rice straw with the dose of 0 (control), 5, 10, 20, 30 tons/ha, respectively, of fresh and weathered was used on two hundred grams of Alfisol soil, and incubated for 56 days. The evolution of CO2 was regularly observed every 7 days for all treatments during the entire incubation period. Soil organic C was measured at the end of incubation period. The results showed that amending Alfisol soil with rice straw enhanced CO2 production compared with the control. Cumulative CO2-C flux (emission) from fresh straw was higher than from weathered one. On the other hand, soil organic carbon from weathered straw was higher than fresh one. In average during 56 days, about 5.76 % of C was emitted as CO2, and the remaining 94% C still retained in the soil as soil organic C. Return of rice straw back into the soil might enhance soil C storage and could improve soil fertility and environment quality.

Keywords: CO2-C flux; fresh straw; soil organic carbon; wheatered straw

Date published: 2019-02-08