Browsing by Author "Kiiza Kabasiita, Juliet"

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    Decomposition and nutrient release patterns of municipal solid waste compost in two agro‑ecological zones of Uganda
    (Agriculture & Food Security, 2022) Kiiza Kabasiita, Juliet; Opolot, Emmanuel; Sande, Eric; Malinga, Geoffrey Maxwell
    Deteriorating soil fertility is a major constraint to agricultural production and food security among smallholder farmers in Uganda and throughout sub-Saharan Africa, where the majority of the population relies on subsistence farming for its livelihoods. Unfortunately, inorganic fertiliser used as a significant soil nutrient replenishment is unsustainable, causing adverse environmental effects, including soil acidification and pollution of water bodies. Therefore, finding alternative, more sustainable, low-cost nutrient management systems is vital. This study assessed the decomposition and nutrient release patterns of municipal solid waste compost (MSWC) in a 36 weeks litter bag experiment under field conditions in two agro-ecological zones (AEZs) of Uganda. Results: We found a higher rate of decomposition in the South-western Grass Farmlands (SGF) agro-ecological zone (0.041 week− 1, with 20% of initial compost mass remaining after 36 weeks of decay) compared to Southern and Eastern Lake Kyoga Basin (SEKB) (0.043 week− 1, 32% of initial litter mass remaining). The half-life values were 16 and 17 weeks for SGF and SEKB AEZs, respectively. The nutrient release rates differed between the two study sites. The macronutrient release pattern in both sites followed the order K > P > N. The secondary macronutrients release followed the order Ca > Mg in the SGF, while in SEKB, the order was reversed. The micronutrients followed the order Cu > Mn > Fe > Zn and Cu > Mn > Zn > Fe in SGF and SEKB AEZs, respectively. The MSWC mass loss during decomposition was negatively correlated with rainfall in both AEZs and with temperature in SGF AEZ, while it was positively correlated with temperature in SEKB AEZ. However, the relationship with nutrient release rates was inconsistent in both AEZs. Conclusions: Our results showed consistent release of nutrients in all AEZs throughout the study period, which coincides with the two cropping seasons in Uganda, suggesting that smallholder farmers can use MSWC as a soil amendment to address soil fertility decline and improve crop productivity. However, because most nutrients were released almost right away in both AEZs, planting should be done at the beginning of high rainfall months when soil moisture is high to synchronise nutrient release from MSWC with crop demand and maximise nutrient uptake by crops while minimising losses to the environment. Furthermore, the inconsistent relationships between the climatic variables and nutrient release suggest that other factors, such as site-specific microbial composition, influenced MSWC nutrient release. Therefore, long-term research is needed to examine other factors affecting nutrient release in these AEZs.
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    Factors influencing utilization of municipal solid waste compost among urban farmers in western Uganda
    (CABI Agriculture and Bioscience, 2021) Kiiza Kabasiita, Juliet; Malinga, Geoffrey Maxwell; Odongo, Julius C. W.; Opolot, Emmanuel
    Effective management of solid waste is one of the most serious environmental problems confronting urban governments in developing countries due to insufficient financial resources and institutional capacity to provide basic solid waste management infrastructure, impoverished urban populations, low rates and coverage of collection, and rising food consumption rates. Composting has been touted as the most economical solution for reducing organic fraction of urban waste volumes while releasing vital nutrients for the soils. However, there is a paucity of information on utilization and associated factors of urban wastes in Uganda. This study aims to assess the level of utilization of Municipal Solid Waste (MSW) compost produced from Clean Development Mechanism (CDM) plants and associated factors among farmers in Fort Portal and Mbarara Municipalities, western Uganda. Methods: Data was collected using a cross-sectional survey from 359 and 361 randomly selected farmers in Mbarara and Fort Portal, respectively. A semi-structured questionnaire was employed to collect quantitative data and analyzed statistically using SPSS and STATA statistical programs. Probit model was used to determine factors that influence farmers’ decisions to utilize MSW compost as a soil conditioner. Results: The findings revealed a very low level of utilization in both municipalities, 1.7% in Fort Portal and 2.2% in Mbarara. The results indicated that annual farm income, access to other soil conditioners, experience with the use of fertilizers, membership to a farmers’ group and the cost of MSW compost significantly influenced farmers’ decision to use MSW compost. Conclusions: The findings call for government investment in policies aimed at increasing the level of utilization of the MSW compost by improving accessibility to soil conditioners, creating opportunities for maximizing household incomes, farmer-to-farmer experience sharing, dissemination of information through extension programmes and other innovative communication approaches, operationalization of farmers’ groups and introduction of subsidy schemes on the price of compost through operational tax waivers in urban areas of Uganda. Finally, to guarantee quality and to improve the adoption of compost generated at the CDM plants, there is a need for research to assess the quality of MSW compost, undertake a supply chain analysis and cost–benefit study and set a price commensurate with the quality, and develop guidelines and rates of application of the MSW compost.
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    Quality and Fertility Assessments of Municipal Solid Waste Compost Produced from Cleaner Development Mechanism Compost Projects: A Case Study from Uganda
    (Agriculture, 2022) Kiiza Kabasiita, Juliet; Opolot, Emmanuel; Malinga, Geoffrey Maxwell
    Despite the fact that compost projects under the Cleaner Development Mechanism (CDM) have been implemented in Sub-Saharan Africa in recent years, there is a paucity of information on the quality of compost produced from the compost plants. This study fills this gap by evaluating the properties of MSWC produced from 12 CDM plants in Uganda based on quality and fertilizing indices. pH, Pb N, K, P, Mn, Cd, Ca, Mg, Cu, Fe, Cr, Zn, OC, and CN levels differed significantly between locations. MSWC’s Fertility Indices (FI) ranged from 1.9 to 2.9, with Mbarara having the highest (2.9) and Soroti having the lowest (1.9). Fort Portal, Mbarara, Kasese, and Masindi have Clean Indices (CI) ranging from 3.8 to 4.9. According to the results of the fertility and Clean Indices analysis, all MSW composts generated at CDM facilities have low fertilizing capacity and poor quality and are classified as Class RU-1, which does not meet international and national compost criteria. As a result, these composts cannot be utilized as fertilizers and can only be used as soil conditioners under certain conditions. Windrow composting has been proven to be a viable method for lowering huge amounts of organic municipal solid waste in urban areas, and it can be scaled up to other parts of the world according to this study. Authorities must, however, engage urban citizens in waste separation at the source and MSWC enrichment with organic sources. This will aid in improving its quality and fertilizing capacity, as well as in ensuring that the MSWC produced is uniform and suited for use in agriculture and the market.