聚合物包膜肥料养分控释研究进展

聚合物包膜肥料的养分控释机理研究对包膜肥料的开发与应用起着重要作用,国内外研究学者在Fick扩散定理的基础上建立了包膜肥料控释理论和多种数学模型,探索了影响养分释放的因素。聚合物包膜肥料按扩散机制释放养分。养分释放速度的控制因素主要有两种不同看法,一种是养分扩散速率控制,另一种是水蒸气渗透速率控制。肥料包膜层厚度、包膜材料吸水性、温度、水蒸汽压、土壤含水量等均影响养分释放。

Research advances on controlled-release of nutrients in polymer-coated fertilizers

It is important to research the controlled-release mechanisms of nutrients in polymer-coated fertilizers for their exploitation and application.Some models were established on nutrients release in polymer-coated fertilizers according to Fick diffusion theory.There are two different views on the control factors of nutrient release rate： one is that nutrient diffusion rate is the control factors of nutrient release rate,while the other is water vapor permeation rate is the control factors of nutrient release rate.Ideal polymer-coated fertilizers release nutrients by S-shaped curve.The factors affecting the nutrient release of polymer-coated fertilizers include the thickness and water absorption of coating layer,temperature,vapor pressure,soil water content etc.