Effect of zinc on fertilizer utilization rates of nitrogen，phosphorus and potassium ，grain yield and quality in maize

The application of ZnO 4．2kg／hm² has a very obvious synergism function on N and K absorption and utilization of maize，and can increase the fertilizer utilization rates of N and K by 35．84％ and 141．07％ respectively．thus increasing the yield by 7．63％，and can also enhance the contents of protein，fat，starch and total sugar in corn grain by 5．63％，5．37％，2．69％ and 2．29％ respectively．Zn has an antagonistic action on P absorption and utiliza tion．and decreases P utilization rate．