Analysis of the soil hydrological function of steppe agrolandscapes: mathematical models of migration processes

Abstract

Mathematical models of the processes of migration and accumulation of moisture in the soils of steppe agrolandscapes were developed according to the results of the analysis of soil hydrological function. As an example, chernozem ordinary was taken on the territory of the experimental field of the Sinelnikovsky experimental station in a typical steppe agrolandscape with a periodically leaching water regime. Methodical approaches. Mathematical modeling for hydrological processes of migration and accumulation of moisture in different layers of soil to a depth of 1000 cm. A square matrix of analysis was used. The calculations were performed using archival and published results of studies and observations conducted from 1967 to 2000. According to the results of field determination of moisture balance in chernozem ordinary with periodically leaching water regime, it was found: in a soil layer 0-10 cm from 497 mm of precipitation 33.5 % (240 mm) consumed for evaporation from the soil surface; 5.5 % (37 mm) go to stock; 23.7 % (160.4 mm) - for transpiration by plants; 8.8 % (59.6 mm) − filtered in deep layers. Mathematical-statistical models of moisture accumulation were developed for four vertical zones (layers) of the studied soil under black fallow: (1) zone of formation of the main root mass (0-150 cm); (2) zone of the soil texture weighting (150-320 cm); (3) zone of low moisture content (320-500 cm); (4) capillary moisture area (deeper than 500 cm). For a layer of 0-150 cm, the leading factors are established and the share of their participation in the soil moisture balance is calculated: soil bulk density (57.2 %); the content of particle size fraction <0,001 mm (26.8 %); total content of fractions <0.01 mm (9.1 %); soil porosity (5.6 %); field water capacity (1.3 %). Based on the research results, practical recommendations for land users were formulated: improvement of the soil hydrological regime and creation of reserves for moisture accumulation in the deeper layers can be achieved by forming a wide range of ecological niches with leaching water regime on arable lands (for example, a system of reclamation forest belts). Thus, the efficiency of moisture accumulation in the agrolandscape was achieved by ensuring the interaction of various agricultural backgrounds with forest-reclamation methods.