控释肥料养分释放动力学及其机理研究 第1报 温度对包膜型控释肥料养分释放的影响

研究 4种包膜型控释肥料养分释放及温度对释放过程的影响。供试 4种肥料具有指数线形和 S线形释放特征曲线。指数线型控释肥料与 SU GIHARA方程和 S线型控释肥料与 ISHIBASHI改进方程有良好的拟合性。4种包膜型控释肥料的养分释放曲线符合初始诱导期校正参数 tau的一级反应模型。具有指数释放特征曲线包膜型控释肥料的 tau可给出零。为了养分的开始释放 ,需要一定量的水分透入包膜肥料内 ,HCRF S70需要透入的水比HCRF E5 0的多。养分释放呈指数曲线形的 HCRF E5 0和养分释放呈 S曲线形的 HCRF S70在释放机理上没有差异。与指数曲线形的 HCRF E5 0相比较 ,S曲线形的 HCRF S70养分释放推迟是由于养分开始释放时所需水分量较大。因此 ,养分释放呈 S曲线形的控释肥料的诱导期依存于温度。

Nutrient- releasing kinetics of controlled release fertilizer and its mechanism-Part 1. Effect of temperature on nutrients release of film -coated controlled release fertilizer

The effect of temperature on nutrient release of four types of filmcoated controlled fertilizer in laboratory is dealed with, which have exponential and sigmoid release patterns.The nutrient release data with exponential release pattern are fitted to the reaction model proposed by SUGIHARA, the data with sigmoid release patterns are fitted to the model proposed by ISHIBASHI with a slight modification.Their nutrient release patterns obey the firstorder reaction model, with a parameter of t \- au to correct for the initial lagperiod. Zero is given to the t \- au for the fertilizer with exponential release pattern. To initiate the release nutrients, a certain amount of water needs to permeate into the filmcoated controlled release fertilizer , HCRFS70 needs more water to permeate than HCRFE50.There is not major differences in the film involved in the release between the HCRFE50 with exponential releasing pattern and the HCRFS70 with sigmoid releasing pattern. Delay in the release from the sigmoidtype HCRFS70 is due to its larger amount of water requirement to start the nutrient release as compared to the exponential type HCRFE50. The initial lagperiod always depends on the temperature.