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Chicken feathers are hazardous to the environment because of their poor digestibility and potential as a source of environmental contaminants. However, this waste contains valuable plant nutrients that can be recovered and used to improve soil fertility and agricultural productivity. The objectives of this study were to evaluate how effective vermicomposting is at recovering nutrients and changes in enzymatic activity during vermicomposting of hydrolysed chicken feather residues (HCFR). The study included four treatments with three replications at different HCFR and pelletized wheat straw (PWS) mixing proportions: (T1) 25% HCFR+75% PWS with earthworms, (T2) 25% HCFR+75% PWS without earthworms, (T3) 50% HCFR+50% PWS with earthworms, and (T4) 50% HCFR+50% PWS (w/w) without earthworms.

Urbanization threatens biodiversity mostly in developing nations where rural-urban migration is high and urban planning is poor to consider nature conservation. Lacks of adequate information on how to integrate urban expansion and nature conservaion is aggravating environmental problems and making mitigatory actions difficult. Here we quantified how Jimma city, a typical fast growing city in Ethiopia, expanded over the past 35 years, predicted change for the next 50 years and mapped priority areas for conservation. Landsat satellite images of 1985 and 2020 were used to map major land cover types and to quantify temporal changes during this period. We used Markov chain model to predict changes over the next 50 years and GIS-based multi-criteriato identify conservation priority areas. Our finding showed adverse effect of urban expansion on the natural habitats. Over the past three decades, built-up areas were expanded by sevenfold (721%; 2227 ha) while croplands were expanded by 34% (4155 ha). In contrast, a substantial shrinking noticed to the natural habitats: forest cover declined by 39% (5209 ha), grass land by 20% (655 ha) and wetland by 28% (638 ha). Our projection of the current trend to the next 50 years indicated the built-up areas may further increase by fourfold (436%; 13565 ha). However, open water, wetland, natural forest and cropland are predicted to decline by 81% (120 ha), 40% (660 ha), 42% (3455 ha) and 55% (8848 ha), respectively. Under current rate of population growth and rural-urban migrations, urban expansion is inevitable. Our study indicated the importance of delineating at least 9040 ha (28%) of the land within city administration which we categorized as high and very high priority areas for conservation of biodiversity. To build inclusive, safe, resilient, and sustainable cities, the urban administrations in developing nations are in need of sound policy, strategies, and planning that support the integration of urban development and nature conservation especially maintaining the existing key biodiversity areas.

Background Adverse drug reaction (ADR) of medications remains an obstacle to achieving optimal disease outcomes. This study aimed to assess the prevalence and associated factors of ADR among Heart failure (HF) patients hospitalized at Mbarara Regional and Referral Hospital. Method A prospective observational study was conducted among hospitalized HF patients from November 2021 to January 2022. Univariate and multivariate logistic regression was employed to determine factors associated with the ADR. Result Overall, 118 HF patients were included in the study with a median age of 43 years. A total of 164 ADRs were identified during the follow-up period of 1011 days. The incidence of new ADRs was 106 ADRs/1000 person-days. The prevalence of ADR was 59.3%. Of the 164 ADRs, 118(71.9%) were probable. The gastrointestinal system was the most frequently (27.5%) affected system. Over half (86, 52.4%) of the ADRs were mild and 96(58.5%) were preventable. Age group 19–59(AOR 0.15[0.03–0.35] at 95%CI, p = 0.013), herbal use (AOR 3.07[1.01–9.32] at 95%CI, p = 0.048), poly-pharmacy (AOR 8.7[2.4–15.77] at 95%CI, p p = 0.004) were significantly associated with ADRs among HF patients. Conclusion More than half of the hospitalized HF patients experienced at least one ADR during their hospital stay. The use of herbal medicines, poly-pharmacy, and drug-drug interaction were associated with a high risk of ARDs whereas the age group 19–59 years was less likely to experience ADRs.

There is little understanding as to whether the addition of biochar requires less fertilizer to obtain the potential yield. Furthermore, the additional yield ascribed to the non-nutrient effects of biochar is ambiguously quantified. Therefore, this study is aimed to elucidate the influence of biochar application rate and production temperature on (i) marginal agronomic efficiency (AELN), (ii) potential yield (Yopt), (iii) the amount of mineral fertilizer required to obtain the potential yield (Fopt); and (iv) nutrient use efficiency. AELN, Yopt and Fopt were calculated after fitting the yield response at different levels of mineral fertilizer with a second-degree polynomial. Application of biochar reduced marginal agronomic efficiency, implying that the plant utilized the applied nutrient more efficiently without biochar at a low dose of mineral fertilizer. Biochar increased potential yield but required more mineral fertilizer to obtain the optimum yield. The non-nutrient associated effect of biochar reached to 39% and is mainly attributed to its liming effect. The effect of biochar on AELN, Yopt, Fopt, fertilizer use efficiency and soil pH were more pronounced at the higher application rate. Addition of biochar, however, increased soil Mehlich-P and carbon content, irrespective of production temperature and application rate. This study demonstrated that the short-term effect of biochar application on fertilizer utilization should be examined with caution in low-input cropping systems because the biochar effects were dependent on fertilizer level, biochar application rate, production temperature and their interactions. Further manipulative experiments are recommended to identify the mechanisms that explain the non-nutrient effect of biochar on yield.

Owing to rapid population growth, sewage sludge poses a serious environmental threat across the world. Composting and vermicomposting are biological technologies commonly used to stabilize sewage sludge. The objective of this study was to assess the carbon dioxide (CO2) and methane (CH4) emissions from sewage sludge composting and vermicomposting under the influence of different proportions of straw pellets. Four treatments were designed, by mixing the initial sewage sludge with varying ratio of pelletized wheat straw (0, 25%, 50%, and 75% (w/w)). The experiment was conducted for 60 days, and Eisenia andrei was used for vermicomposting. The results revealed that the mixing ratio influenced CO2 (F = 36.1, p = 0.000) and CH4 (F= 73.9, p = 0.000) emissions during composting and CO2 (F= 13.8, p = 0.000) and CH4 (F= 4.5, p= 0.004) vermicomposting. Vermicomposting significantly reduced CH4 emissions by 18–38%, while increasing CO2 emissions by 64–89%. The mixing agent (pelletized wheat straw) decreased CO2 emission by 60–70% and CH4 emission by 30–80% compared to control (0%). The mass balance indicated that 5.5–10.4% of carbon was loss during composting, while methane release accounted for 0.34–1.69%, and CO2 release accounted for 2.3–8.65%. However, vermicomposting lost 8.98–13.7% of its carbon, with a methane release of 0.1–0.6% and CO2 release of 5.0–11.6% of carbon. The carbon loss was 3.3–3.5% more under vermicomposting than composting. This study demonstrated that depending on the target gas to be reduced, composting and vermicomposting, as well as a mixing agent (pelletized wheat straw), could be an option for reducing greenhouse gas emissions (i.e. CH4, CO2).

BackgroundInappropriate Anti-diabetic Medication Therapy (IADT) refers to a drug-related problem and includes ‘ineffective drug therapy’, ‘unnecessary drug therapy’, ‘dosage too high’, and ‘dosage too low’. This study aimed to determine the prevalence and factors associated with IADT among T2DM patients at Mbarara Regional Referral Hospital, Uganda (MRRH).MethodA prospective cross-sectional study was conducted at the medical and surgical wards of MRRH from November 2021 to January 2022. One hundred and thirty-eight adult patients aged 18 years and above, with T2DM, were recruited using consecutive sampling. Patient file reviews and interviewer-administered questionnaire was used for data collection. The data were entered into and analyzed using SPSS version 25. Descriptive analysis was employed to describe the population and determine the prevalence of IADT. Types of IADTs were identified using Cipolle’s DRP classification tool. A univariate and multivariate logistic regression analysis was used to identify factors significantly associated with IADT. The P-value of < 0.05 was considered statistically significant at 95% confidence interval.ResultsA total of 138 hospitalized T2DM patients were studied. Eighty (58.0%) were females, and 70 (50.7%) were ≥ 60 years of age. Out of a total of 138 participants, 97 experienced at least one IADT, with an estimated prevalence of 70.3%. ‘Dosage too high’ (29.2%) and ‘dosage too low’ (27.9%) were the most common type of IADTs. Age ≥ 60 years (AOR, 8.44; 95% CI, 2.09–10.90; P-value = 0.003), T2DM duration of < 1 year (AOR, 0.37; 95% CI, 0.11–0.35; P-value = 0.019), and HbA1c of < 7% (AOR, 9.97; 95% CI, 2.34–13.57; P-value = 0.002) were found to be factors significantly associated with the occurrence of IADTs.ConclusionThe overall prevalence of inappropriate anti-diabetic medication therapy among T2DM patients admitted to medical and surgical wards of MRRH was 70.3%. The most common type of IADT in this study was ‘dosage too high’, accounting for almost one-third followed by ‘dosage too low’ accounting for a quarter of total IADTs. Age greater or equal to 60 years, T2DM duration of < 1 year, and HbA1c of < 7% during the current admission were found to be factors significantly associated with the occurrence of IADTs in hospitalized T2DM patients.

It is critical to develop technologies that simultaneously improve agricultural production, offset impacts of climate change, and ensure food security in a changing climate. Within this context, considerable attention has been given to climate-smart agricultural practices (CSA). This study was conducted to investigate the effects of integrating different CSA practices on crop production, soil fertility, and carbon sequestration after being practiced continuously for up to 10 years. The CSA practices include use of soil and water conservation (SWC) structures combined with biological measures, hedgerow planting, crop residue management, grazing management, crop rotation, and perennial crop-based agroforestry systems. The landscapes with CSA interventions were compared to farmers’ business-as-usual practices (i.e., control). Wheat (Triticum sp.) yield was quantified from 245 households. The results demonstrated that yield was 30–45% higher under CSA practices than the control (p &lt, 0.05). The total carbon stored at a soil depth of 1 m was three- to seven-fold higher under CSA landscapes than the control. CSA interventions slightly increased the soil pH and exhibited 2.2–2.6 and 1.7–2.7 times more total nitrogen and plant-available phosphorus content, respectively, than the control. The time series Normalized Difference Water Index (NDWI) revealed higher soil moisture content under CSA. The findings illustrated the substantial opportunity of integrating CSA practices to build climate change resilience of resource-poor farmers through improving crop yield, reducing nutrient depletion, and mitigating GHG emissions through soil carbon sequestration.

Termites can play a localized prominent role in soil nutrient availability and cycling because mound materials are often enriched in nutrients relative to surrounding soil. Mound materials may thus prove to be useful amendments, though evidently mound spatial arrangement needs to be considered as well. Furthermore, it is not known if gradients of soil properties exist from termite mound to interspace sites. Studying both aspects would be required to decide whether spreading of mounds or spatially differentiated management of surrounding crop to accommodate soil fertility gradients would be valid nutrient-management strategies. Mound abundance and mass were estimated at 9 and 4 mounds ha−1, representing 38.9 and 6.3 t ha−1 on Nitisols and Vertisols, respectively. Soil physical and chemical properties were measured on samples collected from internal and external parts of mounds and adjacent soils at 0.5, 1 and 10 m away from mounds. In general, termite mounds were enriched in plant nutrients and SOC on Vertisols but not on Nitisols. Termite mounds constituted only 0.3 to 1.3% of the 0–15 cm SOM stock on a per ha basis but nevertheless the immediate vicinity of termite mounds was a relative fertile hotspot. Hence, under the studied condition, we suggest spatial arrangement of crop around termite mounds according to soil fertility gradient and spatially differentiated nutrient management strategies. Our result suggests recommendation of termite mound spreading for soil nutrient amendment has to consider plant nutrient stock in termite mounds on per ha basis besides their nutrient enrichment. Interesting topics for future investigation would be growth experiment for different crops with mound materials treatment. It would also be interesting to study the effect mound building termite on soil properties under different soil conditions, slope class and land use.

Climate-Smart Villages (CSVs) were established by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) in the East African countries of Kenya, Tanzania and Uganda to test and promote a portfolio of climate-smart agriculture (CSA) practices that have climate change mitigation potential. This study evaluated the soil carbon sequestration potential of these CSVs compared to the control land use that did not have CSA practices. At the one-meter depth, soil carbon stocks increased by 20&ndash, 70%, 70&ndash, 86%, and 51&ndash, 110% in Kenya, Tanzania and Uganda CSVs, respectively, compared to control. Consequently, CSVs contributed to the reduction of emissions by 87&ndash, 420 Mg CO2 eq ha&minus, 1. In the topsoil (0&ndash, 15 cm), CSVs sequestered almost twice more soil carbon than the control and subsequently emissions were reduced by 42&ndash, 158 Mg CO2 eq ha&minus, 1 under CSVs. The annual increase in carbon sequestration under CSVs ranged between 1.6 and 6.2 Mg C ha&minus, 1 yr&minus, 1 and substantially varied between the CSA land use types. The forests sequestered the highest soil carbon (5&ndash, 6 Mg C ha&minus, 1), followed by grasslands and croplands. The forest topsoil also had lower bulk density compared to the control. The findings suggest that CSA practices implemented through the CSVs approach contribute to climate change mitigation through soil carbon sequestration.

There is a research gap related to the combined effects of compost produced from coffee husks and inorganic nitrogen fertilizer (urea). The objective of this study was to evaluate the yield and yield components of wheat (Triticum aestivum L.) under the integrated application of compost and nitrogen fertilizer (urea). A pot experiment was conducted in a lath house to determine the effects of the integrated use of compost produced from coffee husks and nitrogen fertilizer (urea) on the yield and yield components of wheat. The experiment consisted of nine treatments: T1, control (untreated); T2, 5 t ha−1 (8.12 g pot−1) compost; T3, 10 t ha−1 (16.24 g pot−1) compost; T4, 0 t ha−1 compost + 50 kg ha−1 nitrogen fertilizer (NF) (0.09 g pot−1); T5, 5 t ha−1 compost + 50 kg ha−1 NF; T6, 10 t ha−1 compost + 50 kg ha−1 NF; T7, 0 t ha−1 compost + 100 kg ha−1 (0.18 g pot−1) NF; T8, 5 t ha−1 compost + 100 kg ha−1 NF; and T9, 10 t ha−1 compost + 100 kg ha−1 NF. The treatments were arranged in a completely randomized design (CRD) with three replications. The compost was prepared from coffee husks and applied in wet conditions. The findings showed that the addition of compost had little effect on wheat yield and yield components in the absence of nitrogen fertilizer (urea). However, the application of the highest amount of nitrogen fertilizer (urea), which is equivalent to the recommended field rate (100 kg ha−1) (equivalent to 0.18 g pot−1), and compost (5 t ha−1) (equivalent to 8.12 g pot−1) led to a significant (P≤0.05) increase in grain yield. Under this treatment, the grain yield was 26 g pot−1 (equivalent to 14.741 t ha−1) which is a 66.29% increase compared with the control (8.9 g pot−1 (4.969 t ha−1)); in the treatment in which only the recommended amount of nitrogen fertilizer was used (21.98 g pot−1 (12.273 t ha−1)) grain yield increased by 16.74%. Spike length and dry matter yield also significantly (P≤0.05) increased with the application of integrated compost and nitrogen fertilizer (urea). The results of this experiment revealed that compost-based soil management strategies can enhance wheat production, thereby contributing positively to the viability and benefits of agricultural production systems. However, nutrient-compost interactions should receive special attention due to the great variability in the properties of compost, which may depend on the type of organic materials used.

Although microbial inoculants are promoted as a strategy for improving compost quality, there is no consensus in the published literature about their efficacy. A quantitative meta-analysis was performed to estimate the overall effect size of microbial inoculants on nutrient content, humification and lignocellulosic degradation. A meta-regression and moderator analyses were conducted to elucidate abiotic and biotic factors controlling the efficacy of microbial inoculants. These analyses demonstrated the beneficial effects of microbial inoculants on total nitrogen (+30%), total phosphorus (+46%), compost maturity index (C:N ratio (-31%), humification (+60%) and the germination index (+28%). The mean effect size was -46%, -65% and -40% for cellulose, hemicellulose, and lignin respectively. However, the effect size was marginal for bioavailable nutrient concentrations of phosphate, nitrate, and ammonium. The effectiveness of microbial inoculants depends on inoculant form, inoculation time, composting method, and experimental duration. The microbial inoculant effect size was consistent under different feedstock types and experimental scales. These findings imply that microbial inoculants are important for accelerating lignocellulose degradation. Higher mean effect sizes have tended to be published in journals with higher impact factors, thus researchers should be encouraged to publish non-significant findings in order to provide a more reliable estimation of effect size and clarify doubts about the benefits of microbial inoculants for composting.

Composting is an effective method to recycle biodegradable waste as soil amendment in smallholder farming systems. Although all essential plant nutrients are found in compost, a substantial amount of nitrogen is lost during composting. This study therefore investigated the potential of reducing N losses by (i) delaying the addition of nitrogen-rich substrates (i.e. poultry manure), and (ii) reducing the turning frequency during composting. Furthermore, we tested the effect of compost application method on nitrogen mineralization. Sugarcane-waste was composted for 54days with addition of poultry manure at the beginning (i.e. early addition) or after 21days of composting (delayed addition). The compost pile was then turned either every three or nine days. Composts were subsequently applied to soil as (i) homogeneously mixed, or (ii) stratified, and incubated for 28days to test the effect of compost application on nitrogen mineralization. The results showed that delayed addition of poultry manure reduced total nitrogen loss by 33% and increased mineral nitrogen content by >200% compared with early addition. Similarly, less frequent turning reduced total N loss by 12% compared with frequent turning. Stratified placement of compost did not enhance N mineralization compared to a homogeneous mixing. Our results suggested that simple modifications of the composting process (i.e. delayed addition and/or turning frequency) could significantly reduce N losses and improve the plant-nutritional value of compost.

Municipal waste is usually composted with an N-rich substrate, such as manure, to increase the N content of the product. This means that a significant amount of nitrogen can be lost during composting. The objectives of this study were (i) to investigate the effect of split addition of a nitrogen-rich substrate (poultry manure) on nitrogen losses and greenhouse gas emissions during composting and to link this effect to different bulking agents (coffee husks and sawdust), and (ii) to assess the effect of split addition of a nitrogen-rich substrate on compost stability and sanitisation. The results showed that split addition of the nitrogen-rich substrate reduced nitrogen losses by 9% when sawdust was used and 20% when coffee husks were used as the bulking agent. Depending on the bulking agent used, split addition increased cumulative N2O emissions by 400–600% compared to single addition. In contrast, single addition increased methane emissions by up to 50% compared to split addition of the substrate. Hence, the timing of the addition of the N-rich substrate had only a marginal effect on total non-CO2 greenhouse gas emissions. Split addition of the N-rich substrate resulted in compost that was just as stable and effective at completely eradicating weed seeds as single addition. These findings therefore show that split addition of a nitrogen-rich substrate could be an option for increasing the fertilising value of municipal waste compost without having a significant effect on total greenhouse gas emissions or compost stability.

The use of agricultural waste for soil amendment is limited in developing countries. Competition between fuel and feed is the major cause for the insufficient application of agricultural waste on cropland. The aims of this study were therefore (i) to investigate variation in agricultural waste allocation between groups of farmers with different livelihood strategies and link this allocation with the nutrient balances of their production systems, (ii) to identify farm characteristics that influence utilisation of agricultural waste for soil amendment, and (iii) to assess demand for urban waste compost. A total of 220 farmers were selected randomly and interviewed using standardised semi-structured questionnaires. Four groups of farmers, namely (i) field crop farmers, (ii) vegetable producers, (iii) ornamental-plant growers, and (iv) farmers practising mixed farming, were identified using categorical principal component and two-step cluster analyses. Field crop farmers produced the largest quantity of agricultural waste, but they allocated 80% of manure to fuel and 85% of crop residues to feed. Only

Dissolved organic carbon (DOC) has recently been proposed as an indicator of compost stability. We assessed the earthworms' effect on DOC content and composition during composting, and linked compost stability to greenhouse gas emissions and feeding ratio. Earthworms reduced total DOC content, indicating larger stability of vermicompost than of thermophilic compost. The concentrations of humic acid and fulvic acid were reduced by earthworms, whereas there was no significant effect on hydrophobic neutrals and hydrophilics. The humic acid fraction was depleted more quickly than the other compounds, indicating humic acid degradation during composting. The optimum feeding ratio decreased DOC content compared to the high feeding ratio. The lowest N2O emissions were also observed at the optimum feeding ratio. Our study confirmed the use of DOC content and composition as an indicator of compost stability and suggested that feeding ratio should be considered when assessing the earthworms' effect on stabilisation and greenhouse gas emissions.

Organic amendments are used to improve soil fertility and maintain agricultural fields in a productive state. Despite these benefits, the use of organic amendments is limited in many developing countries. The overall objective of this thesis is therefore to provide a better understanding of current waste management practices in developing countries and ensure sustainable crop production via the biotransformation of urban waste into a high-quality soil amendment. First, I aimed at determining the causes for the limited use of organic amendments in small-scale urban farming systems. I interviewed 220 urban farmers in Ethiopia and found that competition for agricultural waste between fuel, feed and soil amendment is a major cause for the limited use of organic amendments. I demonstrated that allocation of agricultural waste for soil amendment is linked with farmers’ livelihood strategies. I also studied variation in compost demand among different farmer groups, and the socio-economic variables which explained these variations. Gaseous losses of ammonia and greenhouse gas (GHG) emissions occur during composting of nitrogen-rich urban waste. Several technologies could reduce these losses. However, these technologies are inadequate to fit within the broader farming systems because they are expensive. The second aim of this thesis was to develop low-cost methods to mitigate N losses and GHG emissions from composting, while retaining its fertilising value. Composting by earthworms (vermicomposting) is proposed as a low-cost strategy for minimising N losses and GHG emissions. Using a wide range of substrate qualities (C:N ratio, labile C sources) and other factors (earthworm density, amount of input, and moisture), I showed that vermicomposting reduced N losses and GHG emissions compared with traditional thermophilic composting, but the magnitude of the earthworm effect varied between substrates. Earthworms also change the quantity and composition of dissolved organic carbon during composting. Another low-cost strategy is to delay the addition of N-rich substrates during composting. I demonstrated that addition of nitrogen-rich substrate after the thermophilic phase reduced N losses. Delayed addition of N-rich substrates increased N2O emissions, but reduced CH4 emissions. Delayed addition resulted in compost that was as stable and effective at completely eradicating weed seeds as traditional composting. In conclusion, urban waste compost should be considered as alternative source for soil amendment, particularly in developing countries with competition for agricultural waste. Technologies such as vermicomposting and delayed addition of N-rich substrate are recommended to increase or maintain the nitrogen content of compost, reduce N losses and mitigate GHG emissions.

Aims: The objectives of this study were to evaluate (1) the fertilizer potential of bone char, (2) the effects of wood biochar on plant-available phosphorus (P), and (3) the role of root-mycorrhizae-biochar interactions in plant P acquisition from a P-fixing soil. Methods: Incubation and pot experiments were conducted with a P-fixing soil and maize with or without root hairs and arbuscular mycorrhizae (AM) inoculation. Olsen-, resin-P and plant P accumulation were used to estimate P availability from bone char, co-pyrolyzed bone char-wood biochar, and separate bone char and wood biochar additions produced at 60, 350 and 750 °C, and Triple Superphosphate (TSP). Results: Maize inoculated with AM showed similar P accumulation when fertilized with either 750 °C bone char or TSP. Pyrolyzing bone did not increase extractable P in soil in comparison to unpyrolyzed bone, apart from a 67 % increase in resin-extractable P after additions of bone char pyrolyzed at 350 °C. Despite greater Olsen-P extractability, co-pyrolysis of bone with wood reduced maize P uptake. Wood biochars reduced resin-P from bone char by 14–26 %, whereas oven-dried wood increased resin-P by 23 %. Conclusions: Bone char is an effective P fertilizer, especially if root-AM interactions are simultaneously considered. Biochar influences plant access to soil P and requires careful management to improve P availability.

Thermophilic composting produces a significant amount of greenhouse gases. The objectives of this study were (i) to evaluate the effectiveness of vermicomposting to reduce nitrogen losses and greenhouse gases emissions compared to thermophilic composting, and (ii) to determine the effect of different variables (i.e. carbon:nitrogen ratio, earthworm density, moisture content and carbon quality) on greenhouse gases emissions and earthworm growth during vermicomposting. The results showed that vermicomposting significantly reduced nitrogen loss by 10–20% compared to thermophilic composting. Vermicomposting decreased nitrous oxide emissions by 25–36% and methane emissions by 22–26%. A higher earthworm density increased carbon dioxide emissions by 3–14%, but decreased methane emissions by 10–35%. Earthworm density had a marginal effect on nitrous oxide emissions. Vermicomposting decreased nitrous oxide emissions by 40% with higher moisture and by 23% with lower moisture. Vermicomposting also decreased methane emissions by 32% and 16% with higher and lower moistures respectively. This study showed that the addition of labile carbon sources increased carbon dioxide and methane emissions and earthworm growth, but did not affect nitrous oxide emissions. In conclusion, vermicomposting is effective at reducing nitrogen losses and greenhouse gas emissions from composting. Therefore, vermicomposting could represent an option for reducing greenhouse gas emissions from composting, particularly in developing countries where the existing technical solutions are expensive and difficult to implement.

To investigate the contribution of coffee agroecosystem to soil fertility, soil samples were collected at the depth of 0 to 20 and 20 to 40 cm from four different land usages: coffee agroecosystem, eucalyptus plantation, grazing and cultivated lands. The soil samples were analyzed for texture, active and exchangeable acidity, organic carbon, total nitrogen, available forms of nitrogen and phosphorus, CEC, exchangeable cations and micronutrients. The results indicated that land use systems significantly (P < 0.05) affected all soil quality indicators except sand content, available Fe and Mn. Except for the exchangeable Mg, available Cu and Zn soils at coffee agroecosystem were superior for all soil quality indicators than other land use systems. The highest values of exchangeable Mg, available Cu and Zn were observed at grazing lands while the lowest values were recorded at coffee agroecosystem. Hence, the existing coffee agroecosystem in the study area contributes a significant role to improve the fertility status of the soil. Therefore maintaining the existing coffee agroecosystem, reducing overgrazing and intensive cultivation and integrated use of inorganic and organic fertilizers are recommended to replenish the degraded soil quality parameters in the study area. Key words: Coffee agroecosystem, land use systems, soil quality, Ethiopia.