STUDY OF BIOCHEMICAL AND MICROBIOLOGICAL PARAMETERS DURING COMPOSTING OF PINE AND EUCALYPTUS BARK

To study the possibility of some residues from pulp and paper industry being used as substrates to pro-duce seedlings in containers, three composting experiments were carried out using: eucalyptus bark, pine bark and a mixture (60:40, v:v) of pine bark + eucalyptus bark. Biochemical parameters studied were: acid and alkaline phosphatases, lipase (C10), protease, urease, β-glucosidase and total cellulases. The microbio-logical populations of total aerobic bacteria, total fungi, actinomycetes, nitrifying bacteria, cellulolitic bac-teria and fungi were also evaluated. At the end of the process physico- chemical characterisation of com-posts was also performed. Results showed that in general the highest microbiological populations as well as for enzymatic activities occurred during the thermophilic phase (>40 ºC) of process. According to the physico-chemical characteristics of composts pine bark seems to be the one that can be used more success-fully in the formulation of substrates to produce plants in containers