Productivity of grain crop rotations in the landscape conditions of the Central Ciscaucasia

Abstract
Increasing the yield of the most profitable field crops and their placement in crop rotations is an urgent problem of agriculture. The purpose of the studies is to study the productivity of grain crop rotations with various saturation of winter wheat on various power backgrounds and landscape taxons in the zone of unstable moisturizing of the Stavropol Territory. Productivity of grain crop rotations depends on the developing weather conditions, the introduction of mineral fertilizers, saturation of crop rotations with winter wheat and location in the relief. The maximum yield of grain units was observed in crop rotations with winter crops. In crop rotation with a spring barley, they were collected by 3.5–4.2 с less. The use of fertilizers increased the collection of grain units on average by 4.9–6.1 c/ha. On the outskirts of the placard (A1) due to lower soil fertility the minimum collection of grain units was obtained (20.2 с). On average (A2) and lower (A3) slopes their fee increased by 11.7 c, or 57.9%, and by 14.5 c, or 71.8%. In the first crop rotation with 60% saturation of winter wheat the maximum yield of the grain of this culture was obtained. In the second and third crop rotation with 40% grain saturation wasassembled by 6.2–6.3 c less. Putting fertilizers in a dose of N40P40K40 increased the grain collection in the first crop rotation by 4.1, in the second — by 2.2 and in the third — by2.4 c, and according to taxons: on A1 — by1.4,on A2 — by3.6 and onA3 — by 3.8 c. According to the landscape taxons, the release of grain of winter wheat differed at 7.9–10.2 c with the maximum value on the lower slope. Upon the exit of the grain and feed units on all power backgrounds, 1st and 3rd crop turns were leading, and in the exit of the grain of winter wheat — crop rotation with 3 fields of winter wheat.