The humus status of cultivated soddy-podzolic soils of Northwestern Russia and its transformation under modern conditions

摘要

The humus status of most of the cultivated soddy-podzolic soils in Northwestern Russia is unsatisfactory. It approaches the optimal level by the main parameters only at the stage of good cultivation. The calcareousness of parent materials is an additional optimizing factor. The use of mineral fertilizing systems on well cultivated soils results in quite a rapid degradation of their humus status, while it ensures the maintenance of the initial parameters of weakly cultivated soils.