СРЕДОУЛУЧШАЮЩЕЕ ЗНАЧЕНИЕ КЛЕВЕРА В УСЛОВИЯХ МИНИМИЗАЦИИ ОБРАБОТКИ ДЕРНОВО-ПОДЗОЛИСТОЙ ПОЧВЫ

Abstract

In 2017–2019, the authors studied the influence of the meadow clover on the density, soil structure and biotic activity of sod-podzolic medium loamy lightly-eroded soil under plowing and minimal tillage in a stationary field experiment in the fourth rotation in the conditions of the Udmurt Republic. During the period of clover growth with minimal tillage, the topsoil density was reduced to the optimal parameters for cereal crops (1.29 g/cm3) and overcompaction of the uncultivated soil layer (1.59 g/cm3). Under these conditions, the clover formed a reliable increase in the yield of green mass of 8.9 t/ha relative to the yield obtained during plowing. The structural condition of the soil was described as good. A year later after the application of clover green mass, an aggregate analysis showed an improvement in the structure of the plough layer. The content of the lumpy fraction by plowing decreased by 6.0% in the 0–10 cm layer and 3.0% in the 10–20 cm layer, with minimal tillage of 7.6 and 16.0%, respectively. This made a positive effect on the biotic soil activity. Also, the decomposition level of cotton cloths was in a close positive relationship with the accumulation of small mesoaggregates of 0.5–1 mm in size (in topsoil r = 0.83, in the lower layer r = 0.80). An increase in the fine structure content of 0.25–0.5 and 0.5–1 mm was observed in both versions of soil tillage. As a result, the plow layer acquired an excellent structural condition. The barley of the 2019 yield on clover manure formed 3.70 t/ha of grain during plowing and 3.82 t/ha under the minimum tillage. The obtained results indicate the formation of optimal growing conditions for grain crops with minimal tillage of sodpodzolic medium loamy lightly-eroded soil of the Udmurt Republic due to the environment-improving properties of clover with the application of its green mass for green manure production.