Influence of composition species of green manure crops on soil fertility

Abstract

Abstract The selection of green manure crops for the zones with insufficient and unstable moisture is an urgent issue of agriculture. The purpose of the work is to establish the influence of the species composition of green manure on soil fertility. The research on southern low-humus chernozem was conducted in FSBI “Research institute of agricultural chemistry” in 2016-2019. The climate of the area is continental, semi-arid. The average annual air temperature is 10.8°C, the amount of precipitation is 428 mm. Conducting the experiment, statistical processing of data was performed according to B.A. Dospekhov. Layout of the variants - systematic, repetition is three times. The area of the plots is 720 m2. The subject of the research is agrocenoses of green manure crops. The object of the study is the soil fertility change processes. Agrocenoses of winter rye and triticale, melilot and sainfoin ensured the highest dry matter yield (6-6.3 t/ha). The maximum entry of organic matter into the soil occurred when using agrocenoses of winter rye - 5.88 t/ha and triticale - 5.72 t/ha. Mixture of crops on the entry of organic matter into the soil was inferior to rye and triticale, but outperformed vetch by 17.9%. The greatest amount of nitrogen was contained in the biomass of melilot and Sainfoin - 156 and 142 kg/ha, and in the mixture of winter crops - 108 kg/ha of nitrogen. The mixture combined the positive properties of its constituent crops: high and stable yield of dry and organic matter, nitrogen, phosphorus and potassium. Due to mineralization of the organic matter of green manure crops, there was an increase in nitrate nitrogen in the arable horizon from 1.0-2.4 to 12.0-22.8 mg/kg of soil.