A STANDARD CURVE FOR INTER-SITE COMPARISON OF CELLULOSE DEGRADATION USING THE COTTON STRIP METHOD

Abstract

Cotton cloth was buried in contrasting soils for various lengths of time until close to physical disintegration. Cellulose degradation was assessed by comparing the tensile strength of cloth after recovery with that before burial. A curve was derived for loss of tensile strength of cloth, when rotting under constant conditions. The curve was linearized by a mathematical technique analogous to taking logarithms when there is exponential decay. By means of the linearization, rates of degradation were compared between widely differing sites, using both our own data and reworked data from the literature. The time to 50% loss of tensile strength ranged from 3.2 days in an incubator at 29 °C to 1.2 yr in an arctic tundra. A mathematical model of the decay process suggests that the rate of degradation depends mainly on the physico-chemical environment of the cotton in the soil, and is insensitive to the size of microbial inoculum. Key words: Decomposition, cotton strips, site comparison, cellulose degradation, soil burial test