The biological characteristics of soil offer an indication of its fertility. The following experiments mostly cover soil microflora which, in regard to the number of organisms/g of soil and the live weight (kg/ha), is substantially higher than the soil fauna. In addition to characterisation of the organism groups - both quantitative and qualitative - tests of carbon and nitrogen conversion as well as a number of different physical and chemical parameters are significant for evaluation of biological cycles in soil (Urban in Kuntze et al 1994).