Water Security of Grain Agroecosystems in the Steppe and Forest-Steppe Regions of Russia: 2. Historical Period, Direct Seeding Technology

Abstract

A methodology has been developed for assessing the water security characteristics of grain agroecosystems (by the example of winter wheat crops) in the grain belt of the Russian Federation, using a no-till strategy. The method is based on simulating the hydrothermal regime of an agroecosystem by the SWAP land surface model using standard meteorological information and data on the hydrophysical parameters of the soil and its mulch cover applied within the no-till system. Using the developed methodology, long-term simulations of the water balance components of winter wheat crops grown under rainfed conditions by direct seeding technology were performed for a number of agrometeorological stations located in the steppe and forest-steppe territories of the grain belt of Russia for the historical period from 1977 to 2023 with a daily step. The obtained series of water regime characteristics enabled us to calculate the water security indicator for winter wheat crops, the risk of a moisture supply deficit, the coefficient of the efficient use of natural water resources by the agrocenosis, and the risk of crop failure due to insufficient water supply for crops. These parameters were compared with the corresponding values previously obtained for winter wheat fields cultivated by traditional moldboard plowing technology.