Sources and Forms of Soil Chemical Degradation

Abstract

The main sources of soil pollution, the types and the forms of chernozem degradation are presented in the present article. It was established that in a period of 100 years, as a result of the mineralization processes, 40–47% of the initial humus reserves were lost, which constitutes 0.5–0.6 t/ha or 0.013–0.018% annually. In the course of 105 years, 3.4 t/ha of N, 0.9 tons of P₂O₅ and 6.8 t/ha of K₂O were extracted and exported with the harvest from the soils of the Republic of Moldova. The chemical degradation of the soils led to the intensification of the physical and biological degradation processes, and as consequence the production capacity of the agricultural fields decreased. In order to stabilize or to increase the humus contents in the chernozems, it is necessary to minimize the soil erosion to the admissible limits, to observe the scientifically proven crop rotation system with the quota of perennial grasses of 10–15% and to incorporate an average of 10 t/ha manure and 150–180 kg/ha of NPK per crop rotation annually.