A comparison of the dynamics and carbon stocks in rice fields with different management systems and soil types

Paddy fields in Indonesia, on average, have a very low content of organic matter (organic C < 2%). This organic matter’s low content will affect the carbon stock. The management system as well as soil type could affect carbon stock in the soil. This study aims to determine the dynamics and carbon stock in paddy fields with different management systems and soil types. The research was conducted in Karanganyar Regency; Sukoharjo Regency and Klaten Regency. Factors observed include organic, semi-organic, inorganic management systems and soil types (i.e., ultisol, vertisol and inseptisol). Soil sampling was carried out 3-5 days after harvest. Each combination of the management system and soil type was taken with three soil sample points at two depths (0-20 cm and > 20 cm) with three repeats. The parameters hedied include organic C, dissolved organic C, microbial C, pHH2O, total N, CEC, soil texture and bulk density. Soil depth and the interaction of management systems and soil types affect the total organic C. Total organic carbon is highest in vertisol soils with an organic management system (2.59%) and a depth of 0-20 cm (2.24%). Carbon stock (82.62 tons ha-1) in vertisol soils with organic management systems is higher than in vertisol soils with semi-organic and inorganic management systems, with a C stock of 71.19 tons ha-1 and 68.4 tons ha-1.