The soil fertility improvement of the marginal lands depending on kind of amendments

The major goal of this case study was to estimate the impact of two soil amendments on soil fertility, grain crops yield, and quality. The greatest effect of increasing sweet sorghum biomass produced in loess like loam has been obtained using sewage sludge (SS) at the rate of 80t/ha. Such a reaction has become appropriate to the introduction of nutrients into the "young" soil. The SS applying by rate of 60 t/ha had little effect on the increase in the content of zinc and copper in sunflower seeds in the experiment managed on black soil. Trace concentrations of lead and cadmium are recorded. The addition of vermicompost and a solid fraction of digestate at a rate of 40 t/ha led to an increase in the corn grain yield obtained on black soil at the 20.1 and 35.0%, respectively. The greater starting effect on urease activity was recorded from the introduction of vermicompost compared to the solid fraction of the digestate. The application of the solid fraction of the digestate had a positive effect on the activity of phosphatase in the topsoil in the first part of the season of vegetation.