The Influence of Forecrops, Tillage Techniques and Chemicalization Levels on Soil Moisture, Spring Wheat Grain Dockage and Yield in the Forest-Steppe conditions of Irkutsk Region

Abstract

The aim of the studies was to assess the influence of forecrops, tillage techniques and chemicalization levels on soil moisture, spring wheat grain dockage and yield. The studies were carried out in 2019–2020 in the forest-steppe zone of Irkutsk region. The three-factor experiment scheme included the forecrops: annual grasses (pea-oat mixture) and corn; the basic tillage methods: PLN-4-35 ploughing by 18–20 cm and BDT-3 disk plowing by 8–10 cm; chemicalization level: no fertilizers, mineral fertilizer N45P45K45 (diammofoska and ammonium nitrate) and mineral fertilizer N45P45K45 and herbicides. Differences in the moisture accumulation efficiency between corn and annual grasses, as well as in tillage techniques, have not been established. Decrease in wheat plantings dockage for annual grasses in relation to corn is from 6.2 to 10 pcs/m2. The use of disk plowing leads to an increase in wheat plantings dockage for corn by 23.7–24.3 pcs/m2, for annual grasses by 19.9–27.4 pcs/m2. The use of the herbicide has significantly reduced the number of weed plants for all forecrops, both in terms of ploughing and disk plowing. The wheat yield for corn has ranged from 2.15 to 2.67 t/ha, depending on the tillage and fertilization techniques. The yield after annual grasses has been significantly lower and ranged from 1.62 to 2.26 t/ha. The use of disk plowing has led to a significant decrease in wheat yield for annual grasses by 0.18–0.29 t/ha, and for corn by 0.21-0.23 t/ha. The application of mineral fertilizers has increased the yield for corn by 0.28–0.29 t/ha, for annual grasses by 0.35–0.37 t/ha. The forecrop has had the greatest influence on the yield–45.8%, the share of the chemicalization level influence has been 30.4%.