Comparison of composting dynamics of bovine manure, equine manure, and new shoots of Ulex europaeus L

Abstract

ABSTRACT Ulex europaeus L. is a species worldwide distributed, without commercial use, but has desirable chemical properties for composting, such as suitable carbon/nitrogen ratio; however, its composting dynamics have not been characterized in new shoots. Thus, we compare composting dynamics of U. europaeus new shoots (UE), bovine manure (BM), and equine manure (BM) in physicochemical terms. The composting process was carried out in piles of 1 m3 during 168 d for each individually raw material, and the measurement was performed every 2 d for temperature and 14 d for physicochemical parameters. Also, the electrical conductivity (EC) and toxicity were determined at the end of the composting period. The thermophilic phase was reached only by UE at least two times in the period. Besides, UE had lower moisture and higher pH than EM and BM. A decreasing trend was observed in organic matter, carbon, nitrogen, and carbon/nitrogen ratio, where UE had higher values than EM and BM. The EC was lower in UE, meanwhile, toxicity was slightly higher in UE than EM and BM. These results indicate that the dynamics composting process of UE is better than EM and BM; however, UE requires more time to reach complete compost maturity.