| The comprehensive effects of N, P, K and Ca concentrations on growth, yield, quality, and total N, P and K content of Ipomoea aquatica Forsk were verified by means of Deep Flow Technique (DFT) under energy saving greenhouse condition.The results showed that the conbination of four optimazied factors promoted the grwoth, root activity, yield, quality, and N, P, K content of Ipomoea aquatica Forsk as compared with control.The optimal ration of N, P, K and Ca to achieve highest yield of individual Ipomoea aquatica Forsk was 9.0, 0.5, 4.5 and 4.0 mmol/L respectively.This ration was verified because the growing trend, root vigor, yield, quality and total N, P and K content of Ipomoea aquatica Forsk were superior to CK. |