Investigations on decomposition of foliage of woody species using a perfusion method

Abstract

The time for half of the total oxidizable carbon to be converted into C02 and other gaseous products (t1/2) was studied for five tree species used in agroforestry. The study was conducted in a perfusion system with continuous aeration, and moisture content maintained at field capacity. This method was found to be suitable for studies of the initial stages of tree foliage decomposition. The overall rate was in the decreasing order: Leucaena > Calhandra > Gliricidia > Prosopis > Cassia. Decomposition started rapidly and then decreased rapidly for 2 to 3 weeks followed by a gradual decrease which continued for the remainder of the time. The time for 50 per cent of total oxidizable carbon to decompose was about 19 days for Leucaena, 30 days for Calhandra and Gliricidia, while Prosopis and Cassia took more than 30 days. Leucaena released the largest quantity of total N into the perfusing solution while Cassia gave the l