INFLUENCE OF CELLULOLYTIC ACTIVITY OF THE SOIL AND NUTRIENTS ON THE YIELD OF DURUM WHEAT IN THE STEPPE ZONE OF THE SOUTHERN URALS

Abstract

The yield of durum wheat depends on many factors and the identification of the main ones is an important area of agrotechnological research. The cellulolytic activity of the soil and the content of macronutrients are one of these factors in the conditions of the southern chernozems of the steppe zone of the Southern Urals. Research on durum wheat is being conducted for the first time at the long-term stationary experimental site for crop rotations and permanent crops, established in 1988. In the experiment, such research methods as field, application, ionometric, and Machigina are used. Field experiments were conducted from 2002 to 2020 according to the method of B.A. Dospekhov. Positive results for nineteen years of research are observed in the second version of the experiment, which are manifested in an increase in the yield of durum wheat after black steam in a six-field crop rotation. The yield of wheat grain is 0.92 tons, feed units are 1.17 tons and energy units are 0.69 tons per 1 ha. The increase in yield depends on the cellulose-decomposing activity of microorganisms and the content of nutrients (NO3 -, P2O5, K2O) in the soil and the share of influence is 51.62, 52.43, 35.27 and 36.80 %. A decrease in the cellulolytic activity of the soil leads in the seventh variant of the experiment to the lowest yield and the yield of grain is 0.51 tons, feed, energy units-0.65; 0.38 t/ha. The formation of a low yield of durum wheat occurs despite the influence of nitrates, mobile phosphorus, and exchangeable potassium in the arable layer (0-30 cm) of the soil and the share is 45.45, 31.91, and 42.63 %. The level of the degree of decomposition of linen according to the experimental variants is in the range from 5.4 to 12.6 %. The range of nutrient content is nitrates from 5.1 to 8.0 mg, phosphorus-4.0-4.5 mg, potassium - 31.9-41.0 mg per 100 g of soil. The studied factors are the reason for the change in the yield of durum wheat.