Comparative assessment of the yield of grain crops depending on limiting factors in the conditions of soil conservation agriculture

Abstract. The aim of work – to identify the influence of limiting factors on increasing the yield of grain crops in crop rotations and soil fertility in a sloping landscape. The following methods were used during the study: field, Kosyrev, thermostatic-weight, ionometric, Machigin, Tyurin, quantitative, balance calculations of yield. Scientific novelty. For the first time, the yield of field crops in grain-steam crop rotations was estimated from the influence of meteorological conditions, moisture, mobile forms of nutrients, humus, seedlings and weed infestation in the arid conditions of the Orenburg Trans-Urals. Results. As a result of research (2021–2023), it was revealed that during the growing season (May-August), the average monthly air temperature (18.6 ℃) and the number of dry days (76) adversely affect (55.85 and 67.50 %) the yield (1.00 t/ha) of barley in the lower part of the slope. In the upper and middle parts of the slope, dry days (56.75 and 64.45 %) negatively affect the yield (1.44 and 1.20 t/ha) of barley. Precipitation in the form of rain (116 mm) during the growing season has a beneficial effect (53.05 %) on the yield (1.34 t/ha) of durum wheat in the middle part of the slope. Spring moisture reserves (152.1 mm) in a meter layer of soil have a positive effect (75.15 %) on the yield (1.30 t/ha) of soft wheat in the upper part of the slope. The increase in yield (1.45 t/ha) of durum wheat and (1.44 t/ha) of barley in the upper part of the slope is due to the influence of (72.30 and 56.05 %) phosphorus content (4.7 and 4.1 mg / 100 g) in the arable soil layer by the end of the growing season. In the middle and lower parts of the slope, the yield of soft wheat (1.20 and 1.10 t/ha) depends on the effect (65.50 and 54.01 %) of the residual content (4.7 and 4.4 mg / 100 g) of phosphorus. The use of agrotechnical soil protection techniques increases the yield of grain crops in crop rotations and soil fertility on the slope, especially on the upper part.