Influence of crop rotations on weed infestation of spring durum wheat crops in the steppe zone of the southern Urals

The effect of 6-fields crop rotations in the 6th rotation and permanent sowings of spring durum wheat on their contamination during prolonged use of mineral fertilizers and without their application was studied. In crop rotations with different types of vapors, with appropriate agricultural techniques, a decrease in the contamination of crops by various groups of weeds was noted. The replacement of clean vapors by occupied ones caused a change in the ratio of weeds in the agrocenosis and led to an increase in the number of perennial weeds. The use of mineral fertilizers in crop rotations contributed to an increase in contamination on a fertilized background. In the variants with soil–protective steam, the increase in the contamination of crops for harvesting was 50.2 pcs. on a fertilized background, 49.0 pcs./m² on a non-fertilized background, 61.6 and 66.6 pcs./m² on a sideral steam, respectively. The biological yield of spring durum wheat when cultivated in crop rotations was 2.08–4.32 c/ha on a fertilized background, – 4.31–5.24 kg/ha. Crop yield after sideral steam was 4.32 on a fertilized background, and 5.24 c/ha on a non–fertilized background. The decrease in durum wheat yields in permanent sowing on a fertilized background was primarily due to the high density of the weed component of the agrocenosis.