PERFORMANCE OF FORCED, PASSIVE, AND NATURAL AERATION METHODS FOR COMPOSTING MANURE SLURRIES

Abstract

Poultry manure slurry amended with sphagnum peat was composted by forced aeration (FA), passive aeration(PA) and natural aeration (NA) under high moisture conditions (76%). For each method three replicated piles were builtand monitored over a period of three months. The compost piles had an initial volume of 5 m3 and were 1.2 m in height.Temperature profiles of replicated positions showed a high degree of similarity suggesting that the raw compost wasuniform and the process was reproducible. An ANOVA test was carried out to compare the three treatment methods usingthe weighted average of temperatures inside each pile. The results showed that, for the selected configuration of aerationpipes and schedule, PA (1) had a higher process rate than NA; (2) provided adequate oxygen without the adverse effect ofcooling as observed in the case in FA; (3) was less laborious than FA; (4) was more effective in conserving nitrogen thanFA; and (5) maintained high temperatures (>55C) for a longer time than the other two methods. FA and PA reached to atemperature of 15C, 19 days (29% reduction) and 16 days (25% reduction) sooner than NA method.