The features of the formation of the phytocenosis of perennial grasses in the Far North

Currently, there are different points of view on the issue of biological recultivation of disturbed land. Some experts practically deny the need for recultivation, which is justified by the hypothesis of self-restoration of disturbed landscapes within 3-4 years. Others consider it necessary to carry out a complete engineering and biological. Neither approach fully corresponds to the real picture. The study presents the results of long-term (2016-2018) research on the peculiarities of growth and development of perennial grasses in the forest-tundra zone of the Yamal-Nenets Autonomous district. It is shown that the number of productive shoots of perennial grasses in 4 years after sowing with the introduction of 0.5-1.0 thousand m3/hectare of peat exceeds by 2 times their value in the control, 1.5 thousand m3/hectare - by 3 times. Liming on the background of 0.5 thousand m3/hectare of peat increases the number of shoots by 6.1-11.0 %, 1 thousand - by 24.1-41.7 %, 1.5 thousand - by 19.5-37.8 %. Combined application of peat (0.5-1.0 thousand m3/hectare) and dolomite fl (6-8 t/hectare) increases the root mass in the 0-10 cm layer by 0.52-0.78 and 0.70-0.96 t/hectare, respectively. For the 0-30 cm layer, these values are 1.15-1.60 and 1.42-1.92 t/hectare. The maximum increase in dry matter of grasses (0.89-1.24 t/hectare) is obtained with the introduction of 0.5-1.0 thousand m3/hectare of peat. Dolomite flour has a positive effect on the yield of perennial grasses, especially at the rate of 2 t/hectare. Additional collection of dry matter of grasses here is equal, depending on the peat norm, from 0.4 to 0.65 t/hectare. It is established that mineral fertilizers are the main factor in the formation of a full-fledged grass stand. The highest yield of grass dry matter (3.86-4.36 t/hectare) is obtainedby introducing N135P135K135