聚合物硫包尿素的养分释放特征

Nutrient Release Characteristics of Polymer-Sulphur Coated Urea

对聚合物硫包尿素(简称PSCU)产品的养分释放特性进行了试验研究。试验结果表明,PSCU在抗冲击性和耐磨性上均明显优于硫包尿素(简称SCU);PSCU能明显克服SCU的“破裂释放”模式的缺点,使养分释放更加平缓;硫膜的厚度对PSCU的养分释放期起决定性作用,养分初期溶出率随着硫膜厚度的增加而降低, 养分释放期相对延长;在相同涂硫量的条件下,PSCU养分初期溶出率随着外层聚合物用量的增加而降低,养分释放期相对延长。因而可以通过改变硫膜和聚合物的厚度来调节其养分释放特性,生产具有不同养分释放特性的控释肥料。

Experiments and researches are carried out on the nutrient release characteristics of polymer-sulphur coated urea（PSCU）. The experiment and research results show that the resistance to impact and abrasive resistance of PSCU are better than that of sulphur coated urea（SCU）. PSCU can eliminate the short-coming of ＂burst releasing＂ pattern evidently, which results in the nutrient of PSCU to be released more smoothly. The thickness and percentage of the sulphur coating of PSCU play a key role in its nutrient release duration, the initial releasing rate decreases and the nutrient releasing duration is prolonged as-its thickness and percentage increasing. Under the condition of same percentage of sulphur being coated, the initial releasing rate of PSCU is reduced, and the nutrient release duration is relatively prolonged as the percentage of outer polymer coating is increased. Therefore, the release characteristics of PSCU can be adjusted by changing the thickness and percentage of the sulphur and outer polymer coating.