EFFECTS OF Fe AND DIFFERENT FORMS OF NITROGEN ON UPTAKE AND DISTRIBUTION OF MINERAL ELEMENTS IN CORN PLANTS I. On the N, P, K, Ca, and Mg

The effects of Fe and different forms of nitrogen on uptake, translocation and efficiency of N, P, K, Ca, Mg in corn plants were studied in solution culture under the controlled conditions. The results showed that the different forms of nitrogen could influence contents of N, P, K, Ca, Mg obvirously under the Fe-deficient condition. Comparing to supply with NO3--N using NH4+-N caused a sigificant decline of Ca and Mg contents In young leaves, but under the Fe sufficient condition, this difference was not. found. K content in young leaves declined by using NH4+-N content in young leaves also decreased under the Fe-deficient condition. Under the Fe-deficient condition, NO3--N induced the young leaves to turn to chlorosis, and the P content in them was also higher than that when using NH4+-N. The contents of N, P, K, Ca, and Mg in old leaves, stem and roots were also discussed.