INTENSIVE METHODS OF GROWING PLANTING MATERIAL OF SMALL-SEEDED WOODY SPECIES IN SEMI-DESERT CONDITIONS

Abstract

Background. The issue of the use of hydrophilic polymers in forestry in the arid conditions of the Volgograd region has been little studied and remains very relevant. The changing natural and climatic conditions of the region require careful selection of an assortment of tree and shrub species and preparations that improve their growth, development and resistance to environmental factors. Purpose. Study of the influence of polymer materials on the species of hanging birch (Betula pendula Roth.), branched tamarix (Tamarix ramosissima Ledeb.), black poplar (Populus nigra L.) in arid conditions. Materials and methods. The effect of three forms of Hydrosous polyacrylamide (HS) was studied: granular in doses 0, 30, 60, 120, 480, 960, 1920 kg/ha, powdered at a dose of 480 kg /ha, saturated with macro- and micro-fertilizers at a dose of 480 kg/ ha on birch and tamarix with the use of fine-drip irrigation, the distance between the centers of the seed rows are 40 cm . The seeding rate of class 1 seeds was 7 g/1 m of the seeding groove. The experiment also included options with mulching birch crops with sawdust 1-2 mm thick, peat 1-2 mm and straw 2-3 cm. In the variant of the experiment with black poplar, sowing seeds in a hydrogel suspension, sowing seeds in water, sowing seeds with dry hydrogel granules, sowing dry seeds (control) were used. Freshly harvested seeds, stirring periodically, were germinated for 36 hours in a hydrogel suspension and an aqueous medium. 5 kg of hydrogel polymer, 100 kg of peat, 10 m3 of water and 40 kg of seeds were used for the preparation of the hydrogel suspension, 0.5 polymer, 10 g of humus and 4 g of seeds were added per 1 ha or 1 liter of water. Results. According to the results of the experiment, birch seedlings grew and developed better in the variant with the introduction of a granular polymer of 960 kg / ha – the diameter of the root neck was 4.8 mm, when the polymer was applied at a dose of 1600 kg / ha, the first shoots after sowing appeared after 14 days. When taking soil samples in tamarix crops, its moisture content was 25.8% in the experiment variant with a polymer dosage of 1600 kg/ha, the best density was observed in the experiment variant with a polymer dosage of 3200 kg/ha. The size and yield of 2-year-old tamarix seedlings when hydrophilic polymers were introduced into the soil turned out to be better in the experiment variant with a dose of 1600 kg/ha. The black poplar showed the best growth results in the variant of sowing in a suspension of hydrogels, the linear growth of seedlings in height was 9.6 cm. Conclusions. Sowing germinated seeds of black poplar (Populus nigra L.) in a liquid medium in the presence of hydrogels and fertilizers allows to increase seed germination, reduce the time of emergence of mass seedlings, accelerate growth rates, improve the quality of seedlings. Polyacrylamide Hydrosous allows you to increase soil moisture, lower its density, which is important for the arid conditions of the research region. During the growth and development of plants under the influence of Hydrosous, the diameter of the root neck of seedlings increased, the dynamics of growth in height and the dates of the appearance of the first shoots decreased.