Intensity of grass stand formation on simulation models of pastures for different seasons of use

Abstract

Abstract. The purpose of the research is to substantiate the relationship between the parameter of the greatest growth of plants with a specific rate of grazing of animals on pasture. It is necessary to solve problems with the intensity of animal grazing, and also to establish, according to the data, a statistical relationship between the parameters of the logistic equation that describes the average statistical growth of plants on natural pastures. Research methods. The experiments were carried out at the research sites of the lysimetric complex of the FSC of Agroecology RAS with various soil substrates (Kumskiy sand, Bazhiganskiy sand, chernozem-like sandy loam substrate). Sowing mixtures of multicomponent herbs of the Stavropol selection was performed for further analysis of plant growth and development, taking into account the different season of use. Results. The article presents the equation of the course of growth of the grass stand for the growing season, which proves that even after the removal of part of the phytomass, the plant growth law is preserved according to the principle of the sigmoid curve. The maximum plant height after simulating phytomass etching was recorded on a lysimeter No. 6 and averaged: with phytomass removal of ⅓ – 121 cm, ½ – 97 cm, ⅔ – 61 cm. The smallest average plant height was noted on lysimeter No. 13 – 64 cm. The highest height on this lysimeter was 110 cm with ⅓ removal. The average growth at the end of the growing season of plants for all simulation models was distributed as follows: with the withdrawal of 33 % – 73 %; 50 % – 53 %; 67 % – 31 %. The experiments showed that it is not recommended to remove more than ⅓ of the plant phytomass. The main role is played by the rate of phytomass removal (grazing rate) for the stable restoration of the grass stand of degraded pastures, and it is also necessary to take into account the vegetative period of the plant. Scientific novelty. The relationship between plant growth parameters has been established. It allows you to predict the characteristics of further growth, improve the natural degraded grass stands, establish the sequence of grazing in different areas in accordance with the species composition of plants.