[Ascertaining the effect of KMg fertilization on the organic matter cycle in pine stands with special reference to the cellulose test (author's transl)].

The biological nutrient cycle was activated by applying KMg in relatively young and older pine stands growing in the plain of the GDR on former agricultural sandy soils with substrats from the Younger Pleistocene. Application of KMg stimulated tree growth and had a persistent effect on the microbiological processes of organic matter conversion in the AO horizon and in the humous mineral soil. The cellulose test proved to be suitable for assessing the formation and conversion processes of soil organic matter caused by fertilization as to their effect on soil fertility.