Abstract : During 2004-2006, the nutrient balance of crop rotation pattern under conventional and minimum tillage and influence of different fertilization treatments at the experimental station of Slovak Agricultural University in Nitra was investigated. The crop sequence of maize (Zea mays L.) - winter wheat (Triticum aestivum L.) - spring barley (Hordeum vulgare L.) under seeded with red clover - red clover (Trifolium pratense) - common pea (Pisum sativum L.) and mustard as catch crop was used. The most serious deficit of nitrogen (-57.4 kg ha -1 yr -1 ), phosphorus (-21.8 kg ha -1 yr -1 ) and potassium (-87.8 kg ha -1 yr -1 ) was in control treatments under conventional tillage. Deficit of nitrogen was also found-out in treatments with mineral fertilizers application. However higher deficit of nitrogen (-34.6 kg ha -1 yr -1 ) in an average was noted under conventional tillage. Combination of mineral fertilizers together with incorporation of forecrop plant biomass into soil (PZ) produced small surplus in the nitrogen balance (5.7 kg ha -1 yr -1 in conventional tillage and 6.7 kg ha-1 yr -1 in minimum tillage treatments). The positive results in the phosphorus balance achieved in treatments with incorporation of forecrop plant biomass into soil in both soil tillage treatments, in an average value of 5.25 kg ha -1 yr -1 , contribute to the good soil phosphorous supply. The negative balance of potassium varying from -87.8 kg ha -1 yr -1 (control) to -14.6 kg ha -1 yr -1 (PZ) is acceptable owing to high content of available soil potassium of experimental stand.

Key words: nutrients balance, crop rotation, soil tillage, mineral fertilizers, post harvest residue, nutrients uptake

Presentation: oral