Distribution of carbon and soil quality in drylands of Aceh Besar, Indonesia

The organic matter is an important component of sustainable agricultural systems and as one of the indicators of soil quality. This research aims to estimate the content and distribution of soil organic carbon (SOC) and soil quality index in several soil orders of dryland areas in Aceh Besar Indonesia. SOC of soil was analyzed using the Walkley-Black method while the soil quality index (SQI) was evaluated by using the method of Mausbach and Seybold (1998). The results demonstrated that the contents of soil organic carbon in dryland areas of Aceh Besar District vary from low to very high (0.23-3.95%) depending on soil types. The organic C content on the soil surface, such as Entisols, Inceptisols, Mollisols, Oxisols, Ultisols were generally low (less than 2%), and only Andisols which have a high content of organic C (3.95%). The average organic C content of order of soil are: Oxisols (0,74 ± 0.12%), Ultisols (0.61 ± 0.14%), Mollisols (0.75 ± 0.23%), Inceptisols (0.78± 0.46 %), Entisols (1.76 ± 1.33%), and Andisols (1.82 ± 0.71%) respectively. Soil quality index (SQI) of dryland in Aceh Besar District vary from a low to high with SQI range of 0.45-0.79. To increase the organic matter content and quality of the soils, adding organic amendments and biofertilizers is necessary.