We have been studied the effects of crop-rotation, fertilization and irrigation on the yields of maize in different cropyears characterized
by different water supply (2007 year=dry; 2008 year=optimum) on chernozem soil. Our scientific results proved that in water stress
cropyear (2007) the maximum yields of maize were 4316 kg ha^-1 (monoculture), 7706 kg ha^-1 (biculture), 7998 kg ha^-1 (triculture) in non
irrigated circumstances and 8586 kg ha^-1, 10 970 kg ha^-1, 10 679 kg ha^-1 in irrigated treatment, respectively. In dry cropyear (2007) the
yield-surpluses of irrigation were 4270 kg ha^-1 (mono), 3264 kg ha^-1 (bi), 2681 kg ha^-1 (tri), respectively. In optimum water supply cropyear
(2008) the maximum yields of maize were 13 729-13 787 (mono), 14 137-14 152 kg ha^-1 (bi), 13 987-14 180 kg ha^-1 (tri) so there was no
crop-rotation effect. In water stress cropyear (2007) fertilization caused yield depression in non irrigated treatment (control=2685 kg ha^-1;
N240+PK=2487 kg ha^-1). Our scientific results proved that the effects of abiotic stress could be strongly reduced by using the optimum crop
models in maize production. We obtained 8,6-11,0 t ha^-1 maximum yields of maize in water stress cropyear and 13,7-14,2 t ha^-1 in optimum
cropyear on chernozem soil with using appropriate agrotechnical elements.