Water regime of ordinary chernozem in the cultivation of sunflower in the Volga region

Abstract

The results of research on the study of five variants of sunflower cultivated according to the ExpressSun ™ production system (the predecessor of barley) on ordinary chernozem for 2013-2020 in the Middle Volga region are presented. The purpose of the research is to identify the optimal water regime of the soil with various technologies for growing sunflower in the arid conditions of the Volga region. It was found that the variants with deep non-tillage tillage, in comparison with the traditional technology, to the appearance of sunflower seedlings on average over the years of research provide an increase in the reserves of productive moisture by 7.4-14.3 mm (3.8-8.0 %). The advantage in moisture reserves was established in all layers of the soil and ranged from 2.6 to 20.0 %. The reserves of productive moisture during the sunflower germination period on the variants without the use of complex mineral fertilizers significantly depended on the amount of liquid precipitation for the non-growing period (September-April) preceding the sunflower sowing (r=0,84-92**). The use of fertilizer systems in crop rotation reduced the dependence of spring reserves of productive moisture on the conditions of humidification in the autumn-spring period to 5 % of the significance level (r=0.78*-0.82*). The use of complex fertilizers contributed to a more rational consumption of moisture per unit of production with resource-saving and traditional technologies, compared with other options by 6.2-21.2 %, up to 1075.9-1084.7 m³/ha. The highest conditional net income was established against the intensive background of resource-saving technology – 27422.2 rubles/ha, the maximum profitability for deep loosening of the soil with the use of a biological product – 253.5 %. Based on the obtained data, a low-cost sunflower cultivation technology has been developed, which provides the most rational moisture consumption and the greatest efficiency.