包膜控释肥养分释放特性的研究

以包膜控释肥为试验材料,通过静水释放试验测定其养分释放速率。结果表明,控释肥的养分累积释放曲线呈“S”形或“抛物线”状;影响控释肥养分释放的控释因子主要是温度、包膜厚度及添加剂等;提高浸提温度其释放速率明显加快,增加包膜厚度其释放速率显著降低。控释肥养分释放机理为:水蒸气透入包膜内,逐渐形成饱和养分溶液,同时包膜被水蒸气膨胀,导致膜上微孔增大,使养分逐渐扩散溶出。

Study on Nutrient Releasing Characteristics of Membrane Wrapping Control-Releasing Fertilizer

Taking membrane wrapping control-releasing fertilizer as testing material,through static water releasing test,its nutrient releasing rate was measured.The result indicates that the nutrient accumulation releasing curve of control-releasing fertilizer is "s" shaped or in "parabolic" shape;the control-releasing factors influencing control-releasing fertilizer nutrient release are mainly the temperature,membrane wrapping thickness and additive etc.;increasing the impregnation temperature could speed up obviously releasing rate,but increasing membrane warping thickness could lower obviously releasing rate.The releasing mechanism of the control-releasing fertilizer nutrient is: water steam is impregnated into membrane wrapping,the saturated nutrient solution is gradually formed,the membrane wrapping is simultaneously expanded by water steam,that leads micro-hole on the membrane enlarged,and makes the nutrient to diffuse out gradually.