The Distribution of Nitrogen in Peat-Based Composts of Manure Slurries and Fisheries Wastes

Abstract

ABSTRACT Slurries of manures from sheep, dairy cows and poultry and their composts with peat moss, and composts made from fish and crab scraps with peat moss or brown peat, were characterized for the distribution of different N forms. The total-N in the composts varied from 1.09 to 3.72%, with the fish scrap composts being the richest. The mature composts contained 13 to 44% of the total N as NH4 − and NO−3 + ions, immediately available to plants. The crab scrap composts were richest in mineral N. The distribution of organic N in the mature composts was generally within the ranges found in mineral agricultural soils, except that amino sugar-N was low in the composts, with the highest (up to 2.75% of total N) in those produced from crab and shrimp wastes which are rich in chitin (a N-acetyl glucosamine polymer). It was concluded that the organic N in the composts would be less amenable to losses than the N in easily hydrolyzable biopolymers in the original wastes.