Phosphorus Impacts on Yield and Nutritional Status of Maize

The field experiment with three rates of phosphorus (P) fertilization for maize (OsSK444 and OsSK552 hybrids) up to 2000 kg P2O5/ha were conducted in the spring 2002. For the next growing seasons (2003 and 2004) only ordinary fertilization was applied. In general, maize yields were independent on applied fertilization. Only application of the highest P rate had residual influences on maize yields for the 2003 growing season. Probably very favorable weather conditions for 2002 and 2004 could be resposible factor for low influences of fertilization on maize yields. Also, maize hybrid OsSK552 yielded more than OsSK444. The ear-leaf of maize at beginning of silking (the 2002 growing season only) was taken for chemical analysis. Leaf P, Mg, Mn and Fe concentrations increased by application of the highest rate of P. At the same time, K, Ca, Zn, Cu and Fe concentrations significantly decreased. Especially influences of P fertilization were found for Zn status in maize leaves (70 and 40 ppm Zn, for the control and 2000 kg P2O5/ha, respectively). OsSK552 hybrid characterized by the higher K, Ca, Mg, Cu and Fe, as well as the lower Zn concentrations in comparison with the OsSK444 hybrid.