The degradation of wood specimen burried in the soil by soft rot fungi is influenced by a number of factors. These are in particular the water holding capacity, water content, content of organic matter, pH, content of mineral nutritive substances etc. The results of the interlaboratory tests, carried out within the IRG/WP let presume that the intensity of wood degradation occurs proportionally inverted to the content of organic matter in the soil. But as the soils used differed also in some other regards, this supposition is not to be depended upon. For this reason a number of degrading tests was carried out with one defined type of soil (EMPA compost soil), to which were added quartz sand and a so called „Einheits-erde“ with a high content of organic matter, in such a way that soil-sand and soil-soil mixtures with graduated contents of organic matter were obtained. The tests are not yet completed. The results obtained up to present show: 1. The degradation of wood by soft-rot occurs proportional to the content of organic matter of the test soil. Within the range examined the wood degradation increases with the higher content of organic matter of the soil samples. 2. The non treated beech wood specimens are approximately twice as quickly degraded as the non treated pine sap wood specimens. The weight losses of the non impregnated pine sap wood specimens after 8 and 16 weeks testing time respectively are approximately the same as those of the beech wood specimens after 4 and 8 weeks respectively. 3. The impregnated beech wood specimens are generally more strongly attacked than the pine sap wood specimens with the same retention of preservative. 4. The protective effect of the CKB-salt at identical concentration is considerably higher on the pine sap wood than on the beech wood. Independent from the test time and from the test soil, all impregnated pine sap wood specimens proved to be protected, whereas the beech wood blocks showed no attack only at higher salt-retentions in soil of low biological activity and at short testing times. 5. The results of the bending tests will be given in a later report. 6. It is intended to investigate the influence of other factors of the soil on the degradation of the wood.

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