EFFECT OF ZEOLITE ADDITION TO CHICKEN MANURE NITROGEN MINERALIZATION IN THE SOIL

Suwardi, L.T. Indriyati and I. Goto (1997)

ABSTRACT

Nitrogen (N) concentration in chicken manure differs with the composting and handling processes. To improve N recycling in chicken manure, N loss from the manure must be reduced. Ten sample of chicken manure were collected from Japanese compost companies for analysis of their total N and organic carbon (C). Using the manure of the highest N concentration, chicken manure equivalent to 0,5 g N in combination with citric acid addition, rapid composting ("bokashi" treatment) and pelletizing, was mixed thoroughly with the air-dried soil equivalent to 1 kg oven-dried soil, then wetted to 60% of its water-holding capacity for a 10 week incubation. The total N concentration varied from 23,1 to 63,5 g N kg^-1 based on dry weight basis; higher after short-term composting and drying. Addition of zeolite and pelletizing of chicken manure decreased the N mineralization. Addition of citric acid to chicken manure before pellezeting did not reduce the N mineralization, but addition of zeolite together with citric acic did. "Bokashi" treatment did not reduce the N mineralization, but reduce the offensive odor of chicken manure during composting.