3riedman S P,Mualemy D Diffusion of fertilizers from controlled-release-sources uniformly distributed in soil,Fertilizer Research,1994,39:19~30
4Wang XiuFeng,Ito T,Wang XF.Effect of lowering nitrate nitrogen and elevating potassium concentrationsin the nutrient solution on the growth,yield,and NO3 content in spinach grown in hydroponics.Journal of the Japanese Society for Horticultural Science,1998,67(1):74~80