Features of development of root systems of plants of various cenosis in dry areas of the Volga region

Abstract

The aim of the study was to establish the growth rate of the root and vegetative mass of cenoses (virgin land, fallow land, arable land under spring wheat) in the slope agricultural landscape of the Saratov region at various levels of moisture and fertilizer application. The study of the root systems of cenoses was carried out according to the Taranovskaya method. Samples of spring wheat were taken at the end of the growing season, on phytocenoses - during the flowering period of 75% of plants. The botanical composition of phytocenoses has been determined. The differences in the productivity of plant mass and root mass, in years with different SCC, as well as the introduction of nitrogen fertilizer. The rates of phytocenosis biomass humification are estimated. The proportions of the dominant families on the virgin land and the fallow land were cereals 25%, legumes 45% and complex flowers 30%.On average, the maximum root mass in a meter-thick layer of soil was observed on virgin lands - 1.9 t / ha, the minimum on spring wheat - 1.1 t / ha, intermediate - on deposits - 1.2 t / ha. Under drought conditions, the largest mass of roots in a meter-thick layer of soil was found on the deposit — 0.8 t / ha, with sufficient moisture — on virgin soil — 2.6 t / ha. Under drought conditions, the bulk of the roots are concentrated in the lower soil layers, with high moisture in the upper layers. The introduction of 60 kg / ha of nitrogen in the form of ammonium nitrate increased the mass of the roots of all cenoses by 27.3%. For an average of three years, the maximum amount of humus during humification of plant residues on fertilized (0.40 t / ha) and unfertilized (0.20 t / ha) background is formed under virgin soil.