Effects of agricultural cropping systems on soil water capacity : the case in cross-border Altai

Abstract

Temperate grasslands are called the breadbaskets of the world. Due to most continental climate conditions, humus-rich soils have been developed. These soils are very well suited for grain production. This is why extensive conversions from natural steppe to arable land have been implemented in this biome. The Kulunda Steppe, in Southwest Siberia and Central Asia, occupies large parts of the driest regions of the Eurasian Steppe Belt. It was one of the sites of the Virgin Land Campaign realized in the former Soviet Union in the 1950s and 1960s. Intensive agricultural practices have caused significant soil degradation, mainly through humus loss and soil erosion. This results in the degradation of organic carbon, altering the physical and chemical structure of the chestnut soils and impacting their water storage capacity. Against the background of climatic changes, a further intensification of these processes and conditions is to be expected. To stabilize soil carbon and optimize moisture utilization, it is necessary to extensively introduce worldwide experiences in conservation cropping technologies (such as no-till, min-till, and direct seeding) in the area. This study aimed to determine the effects of different cropping systems on soil water storage and water availability. The study’s initial hypothesis was that the soil conservational cropping system has advantages against the traditional deep tillage (24 cm). This hypothesis was based on extensive global experience studying the effects of different agricultural management systems on soil-water balance. In 2013–2016, an experiment was conducted for the first time in the Kulunda steppe to instrumentally measure soil moisture and matrix potential at 30–60–120 cm depth under traditional and conservation technology using innovative meteorological and soil hydrological stations. Statistically significant advantages of no-till over deep tillage (24 cm) in terms of moisture retention were found, confirming the hypothesis of this study. Besides, this groundbreaking study reveals new possibilities for soil monitoring in the region. The acquired data are applicable for predictive models using remote sensing. Moreover, the results on the management effects for the soil water balance provide basic approaches to soil water monitoring, offering important data for evaluating model results and remote sensing products for the region.