Assessment of a Cattle Manure Vermicomposting System Using Material Flow Analysis: A Case Study from Uganda
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Date
2019
Journal Title
Journal ISSN
Volume Title
Publisher
Sustainability
Abstract
Growth in cattle population is associated with increased manure generation whose current
management in low-income countries is associated with health and environmental problems as
well as low utilization rates. This trend can be reversed by promoting better manure management
technologies. This study assessed vermicomposting as one of the technologies to manage organic
wastes, using the case study in Uganda. A vermicomposting system using cattle manure and
earthworms (Eudrilus euginea) was monitored for one year with the harvesting of products (compost,
earthworm biomass) after every three months. Vermicompost samples from the beginning of the
experiment and after every harvest were analyzed for the following parameters: pH, ash content,
volatile and total solids, nutrients N, P, K, and C. Emissions of CO2, CH4, NH3, and N2O were also
measured. Material flow analysis was used to determine the flows and retention of nutrients within
the system. Results showed that total solids, ash, N, P, and K content significantly increased, while
contents of volatile solids and C, as well as the pH, significantly decreased over time. Of the materials
that entered the vermicomposting system, 46% went to vermicompost, 2% into earthworms, and 52%
was lost to the atmosphere. Substance flow analysis showed that 30% of C went to vermicompost,
69% was emitted to the atmosphere, and 2% ended up in earthworms while 75% of N was transferred
to vermicompost, 7% went to earthworms, and 18% escaped into the atmosphere. The cumulative
emissions were 102 g CO2 kg1 waste, 7.6 g CH4 kg1 waste, and 3.943 105 g N2O kg1 waste on a
dry basis, while NH3 was not detected throughout the measurement time. Compared to other manure
management methods, vermicomposting demonstrated good potential in conserving nutrients as
well as reducing greenhouse gas emissions.
Description
Keywords
Vermicomposting, Cattle manure, Material flow analysis, Greenhouse gases
Citation
Jjagwe, J., Komakech, A. J., Karungi, J., Amann, A., Wanyama, J., & Lederer, J. (2019). Assessment of a cattle manure vermicomposting system using material flow analysis: a case study from Uganda. Sustainability, 11(19), 5173. doi:10.3390/su11195173