The effect of “Build-up” P-K-fertilization on the cellulolytic activity of some soil types

Summary In field experiments on 3 typical Hungarian soils (acid brown forest soil, calcareous chernozem, calcareous sandy soil) the effect of N-, P- and K-fertilization on the cellulolytic activity of the soil, furthermore the interaction between the latter and the grain yield of winter barley, winter wheat and maize were studied. It can be stated that the soil microorganisms need a similar level of nutrient supply to display a more intensive activity as the higher agricultural plants do to bring a higher yield. The one-sided fertilization with high doses causes a depression in the microorganisms, as it appears in the case of the agricultural plants, too. Thus, the biological testing of the soil may serve in some cases, under the conditions of intensive fertilization, as an index of the soil fertility level. Yet the data gained by the cellulose-test cannot be adapted to the fertilizer recommandation system, because they depend very much on soil properties, climatic conditions, etc. of the experimental places. For diagnostic purposes, however (e.g. to detect unfertile parts of field), it may be used as an index-value of soil fertility.