Response of soil microbial community to compost amendment in an organic pear orchard: preliminary data

The effect of a commercial municipal solid waste compost amendment at two rates on some soil microbial parameters in an organic system was studied in a three-year field experiment. The compost enrichment at highest rate significantly increased the total soil microbial activity (measured by FDA test), whereas did not change the density of cultivable bacteria and fungi (measured by standard plate count technique). The soil suppressiveness assessed under controlled conditions using the pathosystem Pythium - Beta vulgaris, was improved by the highest rate of compost, even if significant differences were not found.