硫包衣尿素养分释放特性及国际标准制定的可行性研究

采用蒸馏后滴定法和折射仪法测定了4种不同类型硫包衣尿素的初期养分释放率和静态氮溶出率,并进行了实验室比对工作,探讨了硫包衣尿素养分释放特征及国际标准制定所需的数据处理问题。结果表明:2种测定方法均可获得较好的精密度,并且无显著性差异,但折射仪法操作更便捷、快速,适合企业在线检测。实验室比对试验结果的精密度由ISO 5725—2∶1994测量方法与结果的准确度(正确度与精密度)的第2部分(确定标准测量方法重复性与再现性)获得,符合国际标准制定的要求。

Nutrient Release Characteristics of Sulfur Coated Urea and Feasibility Study of Establishment of International Standard

The initial release rate of a nutrient and dissolution rate of 4 different types of sulfur coated urea are determined using titrimetric method after distillation and refractometer method, and laboratory comparison work is performed, and nutrient release characteristics of sulfur coated urea and data processing problems needed by establishing international standard are discussed. Results show that the two determination methods can obtain better precision, and no significant difference is seen, but the operation of refractometer method is more convenient and quick and is suitable for online testing of enterprises. The result precision of laboratory comparison work is obtained in accord with the second section （determining repeatability and reproducibility of testing standards） of ISO 5725--2：1994 measuring methods and result precision （accuracy and precision）, which meets the requirements of establishing international standard.