Study on determination of nutrient release characteristics of coated urea

Several medias (water, sand and boric acid) were used to study the nutrient release characteristics of two controlled-release fertilizers. The result showed that, with different medias, there is not significant difference in the release rate of the same fertilizer simples. The method that boric acid be used as leach media, can improve experiment speed, and can be a effective measure in detecting long-term Slow/Controlled-release fertilizers simples.