THE EFFECT OF MINERAL FERTILIZATION ON GRAIN YIELD OF MAIZE IN VARIOUS EARLINESS CLASS

The research aimed to determine the effect of mineral fertilization (NPK) on grain yield of maize in various earliness classes. The field experiment was conducted on very good wheat soil complex (degraded chernozem formed from loess) in the years 2006-2009. The analysed factors were NPK fertilization with 150; 300; 450 kgha-1 and non-fertilized treatment. The second order factor was three maize cultivars: early Fido c.v., medium early Grom c.v. and medium late PR38F70. Increase in mineral fertilization (NPK) level influenced a growth of maize grain yield from 8.39 tha-1 on the non-fertilized treatment to 10.69 tha-1after the application of the highest fertilizer dose.