The Development And Evaluation Of Controlled Release Fertilizer For Turfgrass On Coating Material And Technique

In this study, it mainly focused on developing controlled-release fertilizers (CRFs). A new approach was explored to determine the release characteristics of CRFs according to the research of our work-group in China Agricultural University. Investigations on the coating technique, preferences and working conditions of the technique have been described. A new type of coating material and solvent were developed. The evaluation of CRFs on turfgrass was involved in this work. The fluidized bed (STREA-1^TM Aeromatic-Fielder AG, Switzerland) was employed to produce CAU-controlled release fertilizers. New coatings were screened out and 96 kinds of controlled release fertilizers were obtained. The release characteristics of these controlled release fertilizers were also investigated. The main results in this work were as follows:1. Using relative electric conductivity to evaluate the release characteristics of CRFs is feasible. This method is more convenient and reduces the cost.2. It could evidently improve the efficiency of encapsuling fertilizer granules by heating the coating solution with coating material I ,solvent A and B, while no effects on the release rate of CRFs. The optimal heating temperature is 60℃.3. The controlled release fertilizer with coating material Ⅰ and Ⅱ was developed in this study. It shows predominance in price of the coating materials and solvent compared with CAU51. The release rate of CAU61 is slower than that of CAU51 under the same coating thickness.4. Field experiment on turgrass using CAU-controlled-release fertilizers (CAU-CRFs) demenstrates that CRFs has more advantages than traditional compound fertilizers. CAU-CRFs of 61p-2-1-1 and 61p-2-2-2 could improve the growth and apparent quality of turfgrass and it may be used as special fertilizers for turfgrass. For 61p-2-2-3, it is better to apply with split method. 61p-2-2-3 improves the growth of turfgrass more than the special fertilizer Floragard. Additionally, turfgrass grows with 61p-2-1-1 combined with Com-Cat than that of only using 61p-2-1-1.