YIELD AND QUALITY OF WINTER WHEAT, DEPENDING ON CROP ROTATION AND SOIL TILLAGE

Wheat (Triticum) grain is generally used for food due to its grain quality. The two-factorial trial was conducted in the Research and Study farm `Peterlauki', Latvia, with an aim of finding out the soil tillage and crop diversification in rotation effect on winter wheat grain yield and quality. Two soil tillage systems (traditional and reduced) and three crop rotation schemes with different winter wheat (Triticum aestivum) fore-crops (wheat, oilseed rape (Brassica napus ssp. oleifera), faba bean (Vicia faba)) were used. The trial started in 2009. For this paper data from 2016/2017 and 2017/2018 growing seasons was used. Yields harvested in 2017 were significantly (p<0.001) higher than those in 2018 (on average 7.17 t ha(-1) in 2017, 6.18 t ha(-1) in 2018). The highest yield (8.06 t ha(-1)) was gained in the variant where the fore-crop in 2017 had been faba bean. Crop rotation, including only repeated wheat sowings in both years, showed the lowest yield (on average 5.81 t ha(-1)). Crop rotation with oilseed rape and wheat showed a significant wheat yield increase in the following two-year period in comparison to to repeated wheat sowings. A year as a factor had a significant (p<0.05) impact on crude protein content (%), Zeleny index, volume weight (g L-1) and 1000 grain weight (g). Both, volume weight (g L-1) and 1000 grain weight, were influenced (p<0.05) by the crop rotation and forecrop. Zeleny index depended on all researched factors. Crude protein content was influenced by soil tillage method (p<0.0016) and fore-crop (p=0.0052). Hagberg falling number was not influenced by any of the investigated factors.