Study on Releasing Mechanics of Resin -Coated Controlled-release Fertilizer in Soil Based on SUGIHARA Model

To estimate and forecast the nitrogen dissolving rate of resin-coated controlled-release fertilizer in soil plays an important role in recommending fertilization.Laboratory and field trials were carried out to study effects of tempera-ture and water content on nitrogen dissolving rate of controlled-release fertilizer(resin coated,L1),based on SUGI-HARA model.We forecasted L1's nitrogen release on different fertilization dates.Results showed the water content would not be restrictive factor when soil water content exceeded 35% of field capacity,and temperature was the most important influencing factor on nitrogen release.SUGIHARA model was suitable for forecasting L1 nitrogen release re-gression,in which K(the nitrogen dissolution rate constant) was decided by temperature,so different fertilization dates were matched with different K values.This method was simple,practical and high precision on releasing mechanics of resin-coated controlled-release fertilizer in soil.