Cost reduction in plant production, as well as ecological aspects, force farmers to apply numerous modifications in tillage. Usually, they consist in shallowing ploughing and replacing it with cultivating measures not overturning the soil. The aim of the study was determination of the effect of conventional and reduced tillage systems as well as of two levels of mineral fertilization on the yield of spring wheat in the second cycle of crop rotation: potato spring wheat field pea (edible form) winter wheat. The research was carried out in the years 2003-2006 on lessive soil formed from loess included in the good wheat complex. Autumn tillage under spring wheat, cultivar Helia, included the following cultivation measures: A pre-winter ploughing (18-22 cm), B cultivatoring (10-15 cm), C heavy harrowing (8-10 cm). In spring, harrowing was conducted on all plots as well as cultivatoring, harrowing, seeding and harrowing. The second experimental factor was mineral fertilization on two levels: 117.3 kg NPK (50 kg N, 17.5 kg P, 49.8 kg K) and 175.9 kg NPK (75 kg N, 26.2 kg P, 74.7 kg K). The conducted research indicated that replacing pre-winter ploughing with cultivatoring (B) or heavy harrowing (C) resulted in a statistically insignificant yield decrease, by 4.3% and 7.1% respectively, as well as in a deterioration of its structural components. On lessive soil formed from loess, an increase in fertilization with nitrogen, potassium and phosphorus by 50% did not vary significantly the spring wheat yield or its components. Under conditions of a higher fertilization level, the yield increased by 4.1%. Spring wheat yield was significantly modified only by weather conditions in particular years of research. An increase in the yield and its structural components was indicated in the second cycle of crop rotation in all experiment variants, compared to the research from the years 1999-2002. Therefore, it may be concluded that reduced tillage, consisting in conducting shallow cultivating measures not overturning the soil, is well tolerated by spring wheat.

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