Effect of temperature on nitrogen release characteristic of chitosan coated urea

In order to examine the effect of temperature on N release characteristic of CCU(chitosan coated urea),a release experiment was carried out in water at selected temperature(15℃,25℃,35℃,and 45℃).The results showed that there were release differences between CCU and the other coated urea.The lag stage was not observed in the processes of CCU release.Temperature changed the penetrability of coating layer.N release rate of CCU increased with increasing incubation temperature and the temperature enhanced every 10℃,the nutrient release speed enhances approximately 1.5 times,however,the cumulative release curves of CCU at different temperature are of similarity and regularity similar and regulate.Under whatever temperature condition,with the time during dip,the nutrient release rate increased linearly firstly,then kept constant and finally decreased to zero after urea completely solved.There was a linear relationship between the nutrient release and water permeability and the water permeability curves was very similar to the nutrient release curves at any temperature.