Dynamics of Organic Carbon and Nutrients after Organic Waste Addition in an Acid Soil

Organic waste from agricultural industries such as effluent from palm oil mills contains high organic material and can be used as a source of organic material to improve soil quality. The incubation experiment was carried out to evaluate the effect of organic waste from a mixture of palm oil mill effluent with zeolite and chicken manure on pH, total organic C, labile organic C, humic acid C and nutrient in an acid soil. The treatment consisted of a control and the addition of organic waste at 5, 10, 15 and 20 t/ha arranged in a randomized block design with three replications. The incubation experiment was performed for 10 weeks. The addition of organic wastes significantly increased the soil pH, total organic C, labile organic C, humic acid C and nutrients (N, P, and K) and cation exchange capacity (CEC). The addition of organic waste also showed a significant decrease in the exchangeable Al, which is a toxic element found in acid soils. Changes in soil organic C, nutrients and other soil chemical properties showed different trends during incubation. Increased incubation time led to the decreasing trend in pH, total organic C, labile organic C and available P. In contrast, total N, humic acid C, exchangeable K, Al and cation exchange capacity tended to increase with increasing incubation time. The results of this study indicated that organic C, nutrients and other acid soil chemical properties could be improved by the addition of organic waste.

The addition of organic waste could ameliorate soil organic carbon and nutrients of acid soil

The content of soil total organic C, labile organic C, pH, and available P showed the decreasing trend while soil humic C, total N, exchangeable K, exchangeable Al, and CEC had the increasing trend with the increasing incubation time.