EFFECT OF LONG TERM CROP ROTATION AND FERTILISER APPLICATION ON MAIZE PRODUCTIVITY

The effect of crop rotation and the application of fertilisers on maize yield were investigated in a 12-year study (1998-2009) on the chernozem soil type at Zemun Polje, Serbia. The treatments included four cropping systems: continuous maize cropping (CS1); two crop rotation: maize - soybean (CS2) and maize - winter wheat (CS3), and three crop rotation maize - winter wheat - soybean (CS4) and the following fertilising treatments for maize: F1 - no fertiliser, F2 - 180 kg ha(-1) NPK, F3 - 270 kg ha(-1) NPK and F4 - 360 kg ha(-1) NPK. The amount of applied nitrogen fertiliser in soybean was twice lower than in maize. The grain yield, on the average for all years, was the lowest (5.37 t ha(-1)) in continuous maize cropping. In a dominant type of the cropping system in Serbia (CS3), the maize grain yield was 6.82 t ha(-1) and in CS2, was higher (7.60 t ha(-1)), even though the amount of nitrogen fertilisers applied, was lower by 50%. The highest average yield was obtained in CS4 (9.03 t ha(-1)). The application of fertilisers generally significantly influenced maize yield in comparison with control. These results favoured cropping systems with legumes preceded maize due to lower investments necessary to obtain higher yields.