THE INFLUENCE OF POSTAGROGENIC TRANSFORMATION ON BIOLOGICAL PROPERTIES OF SODDY SHALLOW CLAY LOAM PODZOLIC SOIL IN THE PREDURALIE

The aim of this study was to assess changes in biological properties of a postagrogenic soddy shallow clay loam podzolic soil of a 45 years old stationary field experiment of the Perm State Agricultural Academy (Russia) in a grain-grass-tilled crop rotation. The design of the experiment facilitated an evaluation of the ecological recovery of fertilized soils as well as of discontinued tillage, where particular emphasis was put on the soil biota. Discontinuation of tillage and high availability of phosphorus and potassium were found to significantly enhance carbon dioxide production and urease activity, and to reduce phosphatase activity. We conclude that elevated amounts of available nutrients enhanced soil biological activity beyond its natural levels, and that preferential recultivation of such areas would minimize the risks of nutrient losses to neighboring environments.