Abstract
Currently, various types of livestock manure composts have been developing for application to farmlands as an organic fertilizer. Nutrients released from these newly developed composts play an important role in the overall chemical dynamics in soils. In the traditional methods, such as an incubation method, the nutrient release patterns were measured under soil-compost mixing conditions, in which the major cations and anions were not analyzed precisely. Thus, in this study, a new method for measuring early nutrient release pattern from composts was developed using sand column mixed with manure compost and was applied for analyzing the nutrient release patterns for four kinds of cattle manure compost. A sand column of 9.3 cm height and of 5 cm diameter, having the unsaturated sand layer of 2.3 cm height mixed with compost overlain the saturated sand layer of 7 cm height, was prepared. Distilled water was supplied to the top of the column at a constant rate and the pattern of the nutrient concentration in drained water was measured. This could be evaluated as BTC normalized with pore volume. This method performed well in detecting the delayed release of nutrients and the increase in the released K in the pelletized composts compared with the traditional ones.
