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In the field stationary trial in the maize growing region in chernozem soils in two six-plot crop rotations (Al biological with 1/3 of lucerne, 1/3 cereals and 1/3 manured crops - sugar beet and silage maize; A2 cereal and leguminous) winter wheat, the Viginta variety of ecostable type at limited inputs of soil tillage (C1 control, conventional; C2 protective soil tillage) and fertilization (B1 control, 0 NPK or in A2 after spring barley manure 40 t.ha(-1); B2 reduced fertilization, N according to N-an in soil; B3 medium intensity of NPK) was cultivated. Average emergence rate in the trial was 80%. In different years it ranged from 70 to 90%. It was affected statistically significantly by weather, in arid conditions of summer and autumn of 1991/1992 as well as soil cultivation (highly significantly). Other factors, such as a forecrop and nutrition had no more significant effect. On average for six-year period 593 spikes (Fig. 1) and 32.47 grains per spike (Fig. 2) were included in the trial. Average TKW (1000-kernel weight) amounted to 43.02 g (Fig. 3). Average yield of winter wheat after spring barley was 7.31 t.ha(-1) (Tab. III and IV), after lucerne 7.52 t.ha(-1), after pea 6.81 t.ha(-1) and for the six-year period 7.12 t.ha(-1). The yield in treatments of soil tillage was practically identical. In treatments of fertilization the yield was increasing with intensity of fertilization by fertilizers. The difference in yield between the control (treatment B1) and conventional fertilization at medium intensity of fertilization (treatment B3) was 7%. In the given soil-ecological conditions grain yield was most affected by emergence rate and weather. Significant dependence was between grain yield and emergence rate. Statistically significant difference was also recorded between grain yield and precipitation in May. The share of factors which affected significantly the grain yield changed in experimental years and entered into interactions, particularly with weather as well as with a forecrop, fertilization and soil tillage. Greater year stability of grain yield was recorded in protective soil tillage and in the treatment when fertilizers were not applied compared with conventional soil tillage and mineral fertilization. In the years 1991 to 1996 in the Zone of Hygienic Protection of underground waters of grade II Borovce wheat after fabaceous forecrops without fertilizers gave the grain yield of 7.11 t.ha(-1). The growing season of wheat lasted 255 days on average during which 399 mm of precipitation were recorded and sum of positive temperatures attained 1787 degrees C. In protective soil tillage better economic efficiency (Tab. V) was achieved when compared with protective one.