THE INFLUENCE OF SOIL TYPE AND CULTIVATION SYSTEM ON THE SPATIAL DISTRIBUTIONS OF THE SOIL FAUNA AND MICROORGANISMS AND THEIR INTERACTIONS

The aim of the FAM research network (Forschungsverbund Agrarokosysteme Munchen) is to investigate the ecological effects resulting from two different agricultural cultivation systems. This long-term experiment takes place on a landscape scale of a 143 ha farm which is situated in a hilly landscape derived from tertiary sediments. In April 1991 405 soil samples were taken along a 50 m by 50 m grid. One approach taken was to use geostastistical methods. Semivariograms were calculated, punctual kriging was performed and maps of the spatial distribution of the microbial biomass, soil carbon content and the Collembola were drawn. It was shown that management practice and type of cultivation had more influence on soil biota than different soil types. The higher amounts of organic matter in the top soil of grassland areas were reflected both in higher microbial biomass and in larger individual numbers of Collembola. On the whole experimental farm a high correlation (r=0.79) was found between carbon content (C(t)) and microbial biomass, whereas a value of r of only 0. 36 was found between Collembola and C(t).