Influence of irrigation on the temperature regime of chernozem

Abstract

Abstract. The role of irrigated agriculture around the world is increasingly increasing due to the need to ensure the growth of food production in the conditions of climate aridity and soil degradation. The resource potential of the territory of Russia with the current fundamental change in the scientific and technological strategy requires a deeper fundamental study of the problems of irrigation of chernozem soils. Global climate change towards aridization, insufficient natural soil moisture requires the study of the effect of irrigation on the thermal regime of the soil. The purpose of the research is to study the impact of irrigation regimes on the temperature regime and productivity of spring wheat, the primary object of irrigation of the Northern Kulunda – southern light loamy chernozem. Methods. In microplot experiments, variants were tested with a lower moisture threshold of 80 %, 70, and 60 % of the lowest moisture capacity (LW) and a wetted layer thickness of 40 cm, 60, 80 cm, and with a differentiated wetted layer thickness depending on the phase of plant development. Methods for studying the temperature regime and the root system of plants are generally accepted. Scientific novelty. The optimal depth (0–40 cm) and the degree of moistening of the southern light loamy chernozem (HB-60 % HB) were determined, which ensure a favorable temperature regime of the soil under the conditions of Northern Kulunda and a high yield of spring wheat grain. Results. The temperature regime of the southern light loamy chernozem differs in the level of moisture, but remains favorable both during the day and during the growing season. Humidification of the 0–40 cm layer in the range of HB-70 % HB and HB-60% HB is the most optimal, feasible in practice and provides a conditional grain yield of 4.3–4.2 t/ha. To maintain such a regime of soil moisture, 4–7 irrigations are required with a total irrigation rate of 1700–2200 m3/ha, respectively. The largest share of wheat roots (62–76 % of the total mass) is concentrated in its upper part.