缓释和控释肥料快速检测方法及养分释放特性评价研究

Evaluation Study of Rapid Detection Methods for Slow and Control Release Fertilizers and Nutrient Release Characteristics

采用水中浸提释放法,按照缓释肥料国家标准(GB/T 23348—2009)和欧洲标准化委员会(CEN)推荐的控释肥料评价标准,对9种缓释和控释肥料的氮素释放特性进行了评价。结果表明:采用25℃常温浸提法测定与100℃快速浸提法测定,后者的养分释放率加快。用100℃快速浸提法建立预测预报缓释和控释肥料在常温(25℃)下的释放期的回归方程(一元二次方程,相关系数>0.98),预测值与实测值相差1～3 d。对于25℃常温浸提法测定释放期分别为66,84,142,88,218和130 d的包膜肥料样品CRF1,CRF2,CRF3,CRF4,Nutricote和Osmocote,用100℃电导率法预测的养分释放期分别为65,81,142,86,216和134 d,相对误差<3.5%,说明电导率法也可准确快速地预测包膜控释肥料的养分释放率和释放期。

The water leaching and release method is used, and in the light of the national standard the appraisal for slow and control release fertilizers （ GB/T 23348-2009） and the appraisal standards for slow and control release fertilizers recommended by the European Standardization Committee （CEN）, an appraisal is carried out for the nitrogen release characteristics of 9 slow and control release fertilizers. The results show that the determination by leaching at 25 ℃ and by rapid leaching at 100 ℃ indicates a faster nutrient release rate by the latter. The rapid leaching at 100℃ is used to establish the regression equation （ linear quadratic equation, related coefficient 〉 0.98 ） in the release period at 25 ℃ of slow and control release fertilizers, and the difference between the predicted and actual values is 1 ~ 3 d. The coated fertilizer samples are CRF1, CRF2, CRF3, CRF4, Nutricote and Osmocote, with their respective release period determined by leaching at 25 ℃ of 66, 84, 142, 88, 218 and 130 d. The nutrient release period predicted by electric conductivity at 100 ℃ is respectively 81,142,86,216 and 134 d, and the relative error is 〈 3.5%, showing that electric conductivity can also predict accurately and quickly the nutrient release rate and release period of coated control release fertilizers.