YIELD AND QUALITY OF WINTER WHEAT IN VARIOUS FORECROPS AND NUTRIENT STATUS IN THE LANDSCAPE CONDITIONS OF THE CENTRAL CISCAUCASIA
Studying ways to increase food grain production in different landscape conditions is relevant. The study was carried out in 2016-2019 on the experimental plot «Agrolandscape» Federal state scientific institution «North-Caucasian Federal Scientific Agricultural Center» in the zone of unstable moistening of the Stavropol territory. The aim of the research was to identify the effect of forecrops and conditions of mineral nutrition on yield and grain quality of winter wheat on different taxon in Tashlyansky landscape. The best forecrop of winter wheat was peas. Due to fertilizers application the gain for winter rape was 0.77 t/ha, for peas - 0.82 t/ha and for winter wheat - 0.92 t/ha. Significant difference in the nutrient status was observed for all forecrops, by taxa A<sub>2</sub> and A<sub>3</sub>, and between peas and winter rape and winter wheat, and taxa A<sub>1</sub> and A<sub>2</sub> and A<sub>3</sub>. The yield size and grain quality increased from less fertile to more fertile taxon. Yield compared to A<sub>1</sub> increased in A<sub>2</sub> by 1.9, and A<sub>3</sub> - 2.1 times, and the amount of wet gluten - by 4.1 and 5.4% respectively. This trend was observed in the efficiency of fertilizers as well. Gain after their introduction for A<sub>1</sub> was 0.52 t/ha, for A<sub>2</sub> - 0.95 t/ha and for A<sub>3</sub> - 1.04 t/ha. The highest grain quality was formed by the forecrop peas. For the other forecrops the amount of wet gluten was reduced by 1,7-2,0%. Fertilizer application increased its content for the forecrop peas by 1.8%, winter rape - 2.5%, bastard fallow - 2.1%, for A<sub>1</sub> - 2.4%, A<sub>2</sub> - 1.8% and A<sub>3</sub> - 1.9%. On the average grains for A<sub>3</sub> corresponded to rank 3, A<sub>2</sub> - 4 and A<sub>1 </sub>- 5. Significant differences in the wet gluten content were observed between the taxa A<sub>1</sub> and A<sub>3</sub>.