Resource - saving technology for growing woody species in lowland landscapes of light chestnut soils in southern Russia

Introduction. Environmental factors that limit the growth and development of planting material in the dry steppe and semi - desert are low precipitation, summer droughts, high evaporation, and alkalinity of the soil. The applied agricultural technology often does not provide optimal environmental conditions for rooting of seedlings. In order to eliminate the shortcomings of the existing technology for growing planting material, polymeric materials are of interest that can create optimal conditions for retaining moisture in the soil, enhance growth and increase the resistance of seedlings and saplings to adverse environmental conditions. Materials and methods. Experiments to study the effect of hydrogels and film on the rooting of cuttings were laid out on light chestnut, heavy loamy soil with a humus content of 0.2-0.3% (coordinates of the experimental plot 48.6482, 44.4354). The following options were included in the experiment: I - hydrogel + film; II - film; III - hydrogel; IV - control. Dry granules of SPG were scattered evenly over the surface at the rate of 100 g/m2 and embedded together with fertilizers in a 0-30 cm soil layer (options I and III). After harrowing, the soil surface in options I and II was covered with a black water - permeable film. Results. In conditions of flat relief, cuttings should be planted on clean or green manure fallow, where the soil is freed from weeds. However, in heavily weeded areas, it is not possible to completely get rid of weeds. A particularly large number of weeds in the experiments was found in options without film coverage: white amaranth (Amaranthusalbus L.), wild oats (Avenafatua L.), shepherd’s purse (Capsella bursa - pastoris (L.) Medik.), creeping wheatgrass (Elytrigiarepens L.) Desv.exNevski). In the variants with film mulch, weeds are almost absent throughout the growing season. Under the protection of the film, more lateral roots appear throughout the underground part of the cuttings, the root system is highly branched. It has been established that the mulching film not only suppresses the growth of weeds, but also, together with the hydrogel, improves the hydrothermal and air regimes of the soil. Cutting seedlings growing against the background of hydrogels and film have a higher water - holding capacity and leaf hydration compared to the control, which increases their resistance to drought. Discussion. When cutting willows and poplars in open ground, under the influence of hydrogel and black water - permeable film, the rooting of cuttings significantly increases, the development of root systems improves, and the growth rate of shoots increases. By the end of the growing season, the willow and poplar cuttings rooted under the action of gels and films significantly surpassed in their development the cutting seedlings growing in the control. When dug up, some of the swollen hydrogel granules are firmly retained on the roots, which reduce stress during storage, transportation and planting of plants and contribute to good survival of seedlings. Conclusion. It was revealed that the use of hydrogels allows, by increasing the moisture capacity of light soils, reducing the bulk density of heavy soils, reducing evapotranspiration, to reduce irrigation rates by 20-40%, reduce nutrient losses and fertilizer consumption by preventing their leaching from the soil. It was confirmed that mulching films prevent the formation of a soil crust, eliminate the need for soil loosening, preserve its structure, and reduce crop care costs. The introduction of hydrogels into the arable soil horizon a year before planting allows for the accumulation of precipitation moisture and the creation of an optimal water and air regime for the growth of seedlings. Abstract. The article presents the results of the application of an original resource - saving technology in the cultivation of tree species valuable for forest reclamation and landscaping in an experimental nursery located on a flat landscape of light chestnut soils in an arid region. Proposals for practical application and directions for future research. The research results may be useful in the cultivation of tree seedlings in conditions of limited moisture in the dry steppe.