THE INFLUENCE OF AGRONOMIC FACTORS ON THE GRAIN YIELD OF WINTER WHEAT

In the conditions of the Czech Republic, winter wheat is one of the most widely grown crops as well as cereals on arable land. The aim of the contribution was to find out the influence of different agronomic factors (pre-crop, soil tillage) as W ell as the year on the subsequent winter W he at grain yield in the conditions of dry land of Southern Moravia. The field experiment was conducted at the Field Trial Station in Zabeice (Czech Republic) in 2015-2017, located in the maize production area. The pre-crops for winter wheat included winter wheat, pea, alfalfa and silage maize. Two ways of soil tillage were used in the experiment, namely ploughing (to a depth of 0.24 m) and shallow loosening (to a depth of 0.15 m). From the results obtained in three years it was found that 1,vinter 1,yheat grain yield was influenced especially by the year, the pre-crops and by combination of these two factors with soil tillage. On the other hand, statistical significance for the influence of soil tillage was not found. The yield difference between both methods of soil tillage amounted to negligible 0.1 1 t/ha. In teiiiis of pre-crop, the highest winter wheat grain yields were achieved after alfalfa as a pre-crop (10.60 tlha), the lowest yields were after winter wheat as a pre-crop (9.53 t/ha). Statistical significance was found among the pre-crops. The results from 2015-2017 also showed that the year is one of the generally most unpredictable factors which can cause different results and play an important role in generating yields. Statistical significance among individual interactions was also confirmed.