Results of fifteen-year monitoring of winter oilseed rape (Brassica napus L.) production in selected farm businesses of the Czech Republic from the viewpoint of technological and economic parameters

The paper presents field trials focused on technological and economic comparison of conventional tillage (CT) and reduced tillage (RT) technologies of soil cultivation and drilling of winter oilseed rape (Brassica napus L.). During fifteen production years starting in 2001/02, trials were set up in 520 fields of around 40 farm businesses located in all of the districts of the Czech Republic. With respect to average seed yields, no significant differences were proved with respect to tillage systems, to the application of organic fertilizers and to the fertilization during sowing. Irregular distribution of trial fields into the individual production areas influenced the outcomes thou. Concerning winter rape seed yields, costs per production unit, and earnings per hectare, the most suitable production area proved still to be the potatoes one, but particularly over the recent period also beet production area. The corn production area produced, despite some exceptions, worst results. Over the fifteen-year time, the average oilseed rape yield of all 520 monitored fields was 3.72 t ha–1 . Reduced tillage attained average yield of 3.73 t ha–1 , i.e. matched almost exactly the one of 3.70 t ha–1 attained by conventional tillage. Unit production costs realized by conventional tillage surpassed by 4.1% those gained by reduced tillage. Related earnings per hectare were on the other hand lower by 17.0%. With respect to fuel and labour consumption, reduced tillage brought significant savings reaching in average 20.2%, respectively 24.0%. In terms of yields, reduced tillage with deeper soil loosening proved repeatedly favourable results.