INFLUENCE OF CROP ROTATIONS ON SOIL DENSITY

Abstract

The survey objective is to study and evaluate soil density as one of its most important agrophysical properties. А two-factor experiment was conducted with two establishment of trial in 1996-2021 yrs.: factor A – crop rotations (one grain-grass and three fruit-changing), factor B – the level of mineral fertilizers. For the first time in the Mari El Republic, it was studied and found that the soil bulk density under perennial legumes in a layer of 0-20 cm was 1.34-1.28 g/cm³, under winter crops 1.29-1.28 g/cm³, spring crops 1.26-1.24 g/cm³, potatoes 1.15-1.12 g/cm³. Soil density decreased by the end of the growing season. Long-term fertilizations promotes the root development and leads to soil decompaction. The lowest average density per rotation was under the crops of the second crop rotation, where manure was used for potatoes. It was 1.24-1.23 g/cm³ at the beginning of the growing season. Potato cultivation increased soil density by 0.01 g/cm3 without organic fertilizations in crop rotations I and III. Perennial grasses without growing potatoes further increased the soil density at the vegetation beginning to 1.27-1.26 g/cm³. This trend persisted under crop rotations by the middle of the growing season. The difference between the soil density of grain-grass and fruit-changing crop rotations was 0.03-0.04 g/cm³ by the vegetation end.