The study of soil organic carbon rate in Gunungsewu Karst Area, Pracimantoro District

Abstract Karst landscape has a notable role in carbon cycles. The role isn’t merely through the karstification (solutional) process but also on soil since Soil Organic Carbon (SOC) is the biggest terrestrial organic carbon stock. The purpose of this research was to discover characteristic and calculate organic carbon within rainfed paddy, dry land seasonal crops, shrubland, and homogenic forest in Gunungsewu Karst, Pracimantoro District. The soil sampling method was determined by purposive, then computed through a laboratory test to figure out the soil texture, permeability, bulk density, particle density, porosity, and organic carbon percentage. C-organic assessment refers to the calculation by National Standardization Agency. Permeability is the obvious parameter that was discovered. Soil permeability in the agricultural land uses has a higher value than in non-agriculture land uses. This matter is caused by soil tillage as a human agriculture activity. The result of the SOC assessment is that non-agriculture land use has a higher rate than agriculture land use. SOC within the homogenic forest was the highest rate (30,03 tonnes ha-1), and the dry land seasonal crops was the lowest rate (18,9 tonnes ha-1), whereas the rainfed paddy and shrubland, respectively 21,63 tonnes ha-1 and 23,62 tonnes ha-1. It caused by the litter on the agriculture land use was slightly than the litter that piled up on the non-agriculture land use because the land was tillage and cleaned as an agriculture activity. Research like this should be undertaken in order to gain information about soil or karst roles within carbon cycles as a mitigation to climate change.