The effect of selected factors of production on yields and contents of N-substances in malt barley grain

The objective of the three-year small-plot trial was to assess the effect of the weather of the year, forecrop, variety, form of sulphur (elementary and sulphate) and additional nitrogen fertilising on the yields and the content of N-substances of the malt barley varieties Jersey and Sebastian. The trial was carried out in 2006–2008 at the experimental site of the Mendel University of Agriculture and Forestry in Brno, the Žabčice locality. The Jersey and Sebastian varieties were grown after three different forecrops – winter wheat with ploughed down straw, sugar beet with ploughed down tops and maize for grain with ploughed down straw. The fertilising treatments differed in the form of sulphur (elementary and sulphate) and date of the additional nitrogen fertilising. As the sulphate form we chose ammonium sulphate (40 kg . ha−1 N and 45.6 kg . ha−1 S) and the same amount was supplied in the form of elementary sulphur; nitrogen was in the form of urea. A dose of 30 kg . ha−1 of ammonium nitrate with limestone (ANL) was applied as additional nitrogen fertilising. The results show that the weather conditions of the respective years had an almost 94 % effect on yields. The very strong effect of the weather overshadowed the effect of the forecrop (3.8 %); the effect of the variety was only half that of the forecrop (1.8 %). The form of additionally applied sulphur and nitrogen during cultivation had a relatively little effect on the yields (0.2 %). The forecrop affected the content of N‑substances most of all (47.3 %). The quality of barley grain is markedly dependent on the course of the weather of the year (40.1 %); the effect of the variety on the content of N‑substances was relatively low (1.6 %). Applications of various forms of sulphur had a small effect on the grain quality (0.01 %), while the effect on additional nitrogen fertilising on the content of N-substances was 8.5 %.