Pilot Study On Coated Slow/Controlled Release Fertilizer And The Determination Of Slow/Controlled Fertilizer

As a representative of the fertilizer, slow/controlled release fertilizer has the high utilization rate and little pollution to the environment and low resource consumption. This study involved the following three parts.1.Slow/controlled release fertilizer pilot study using modified waste oil as the coated material.The production was prepared by modified waste oil as coated material A, polyisocyanate and same additives as coated material B on the surface of large granular urea.The results show that the coating process is film temperature was 60℃,spray pressure was1.5MPa, injection velocity was 0.5kg/h,coated material A and coated material B were mixed for coating,and accounts for 6 wt% of the total product, the material mixture were fed in three times with different loading of 3%, 2%, 1% respectively.In this way,the new product not only reached the GB standard, but also show the potential to in lower cost.2.With the coated slow/controlled release fertilizer and nugget slow/controlled release fertilize as studying objects,this study analyzed the correlation between release in water and in field soil of them.Under the same accumulative releasing ratio,the time of release in water as variable(x),the time of release in field soil as variable(y).For coated Slow/controlled release fertilize,the results show that the time release in water and in field soil are linear relationship.The theoretical equation is y=1.0458x-0.9029(R2=0.99).For nugget Slow/controlled release fertilize, the results show that the time release in water and in field soil are linear relationship.The theoretical equation is y=6.6579x-2.0414(R2=0.99).3.Effects of different soil water content and different environment temperatures on release rule of coated slow/controlled release fertilizer and nugget slow/controlled release fertilize.For coated Slow/controlled release fertilize,the results show that when soil water content increased from 10% to 70%,the cumulative nutrient release rate become greater with the soil moisture increasing When soil moisture was 70%, the cumulative nutrient release rate of coated Slow/controlled release fertilize was the greatest.When soil water content increased from 70% to 100%,the cumulative nutrient release rate become decreasing with the soil moisture increasing.For nugget Slow/controlled release fertilize,the results show that the cumulative nutrient release rate become greater with the soil moisture increasing form 10% to 100%.Effects of different environment temperatures on release rule of coated slow/controlled release fertilizer has obvious characteristics of period.In the range of 0~10℃and 20~30℃,temperature did not show definitely influence on the cumulative nutrient release rate.In the range of 10~20℃and 30~40℃,temperature has prominent effects on the cumulative nutrient release rate.For nugget Slow/controlled release fertilize,In the range of 0~40℃,temperature has prominent effects on the cumulative nutrient release rate.