The contribution of biodiversity to the global economy, human survival, and welfare has been increasing significantly, but the anthropogenic pressure as a threat to the pristine habitat has followed. This study aims to identify habitat suitability, analyze the change in habitat quality from 1988 to 2018, and to investigate the correlation between impact factors and habitat quality. The InVEST habitat quality model was used to analyze the spatiotemporal change in habitat quality in individual land-use types in the Winike watershed. Remote sensing data were used to analyze the land use/land cover changes. Nine threat sources, their maximum distance of impact, mode of decay, and sensitivity to threats were also estimated for each land-use cover type. The analysis illustrates that habitat degradation in the watershed was continuously increasing over the last three decades (1988 to 2018). Each threat impact factor and habitat sensitivity have increased for the last 30 years. The most contributing factor of habitat degradation was the 25.41% agricultural expansion in 2018. Population density, land-use intensity, elevation, and slope were significantly correlated with the distribution of habitat quality. Habitat quality degradation in the watershed during the past three decades suggested that the conservation strategies applied in the watershed ecosystem were not effective. Therefore, this study helps decision makers, particularly regarding the lack of data on biodiversity. It further looks into the conflict between economic development and conservation of biodiversity.

Central Rift Valley (CRV) Ethiopia is an important region in terms of its vast ecosystem services (ES)and enriched biodiversity. However, its ES and biodiversity are under terrific pressure from hurried population growth, unsustainable developmental activities, unplanned urbanization, aggressive agricultural expansion, climate change, and the associated changes in land use and land cover (LULC). This study was aimed at analyze LULC changes in the Ethiopia CRV areas from 1985 to 2015 through Geographic Information System (GIS) and Remote Sensing (RS) techniques. Satellite images were accessed, pre-processed and classified. Field observations, discussion with dwellers (elders) were also employed to validate results from remotely sensed data. Major LULC types were detected and change analysis was executed. Consequently, nine LULC changes were successfully evaluated. The classification result revealed that in 1985 the area was covered by 44.34% with small-scale farming followed by mixed cultivated/acacia (21.89%), open woodland (11.96%), and water bodies (9.77%), respectively. Though the area measure varied among land use classes, the trend of share occupied by the LULC types in the study area remained the same in 1995 and 2015. In this research increase in small and large-scale farming, settlements and mixed cultivation/acacia while a decrease in water bodies, forest, and open woodlands is noted. Accordingly, the overall accuracy of this study was 84.46, 86.86 and 88.86 with kapa value of 0.82, 0.84 and 0.87, respectively. Lastly, the DPSIR framework analysis was done and integrated land use and policy reform are suggested as a response for sustainable land use planning and management.

The success of soil management depends on understanding of how soils respond to agricultural land use practices over time. Nitisols are among the most extensive agricultural soils in the Ethiopian highlands but soil degradation threatens their productive capacity. In this study, the effects of two land use systems, intensive cereal and agroforestry systems, and slope class on physical and chemical characteristics of some Nitisol profiles were investigated. In total 12 sample profiles were described and soil samples were collected from each of the identified master horizon. Soil physical characteristics evaluated were particle size distribution, structural aggregate stability, water holding capacity and bulk density. Chemical characteristics determined were exchangeable bases and cation exchange capacity, soil pH and the contents of organic carbon (OC), total nitrogen (TN), available phosphorus (AP) and some micronutrients. Among the physical characteristics, land use and slope significantly (p < 0.05) affected particle size distribution and plant available water content. The mean sand (28%) and silt (26%) particles in the intensive cereal system were significantly (p < 0.05) higher compared to 15% sand and 18% silt in the agroforestry system. Conversely, the mean values of fine grained texture materials including 39% fine sand, 42% fine silt and 67% clay in the agroforestry system were significantly higher than 30% fine sand, 21% fine silt and 46% clay in the cereal system. Similarly, the lower slope had significantly (p < 0.05) higher fin texture materials (39% fine sand, 30% fine silt, and 63%) clay) compared to 17% fine sand, 14% fine silt and 51% clay fractions in the upper slope. The proportion of water stable aggregate (WSA) were highlight (63–94%) and there was no significant difference between land types and slope classes. Following from high structural aggregate stability, the soils have high water holding capacity that ranged from 22 to 32% at PWP to 34–49% at FC while plant available water content (AWC) was in the 120–230 mm m−1 range. Considering the chemical characteristics, land use significantly affected soil pH, total nitrogen (TN), exchangeable magnesium (Mg2+), potassium (K+), percent base saturation (PBS), and available micro nutrients—iron (Fe2+), manganese (Mn2+) and zinc (Zn2+). The mean pH value (5.29) in the intensive cereal system strongly acidic while the pH value for the agroforestry system (6.12) was taken moderately acidic. The mean OC content was 2.0 and 2.1% for the intensive cereal and agroforestry systems that were rated very low. The mean TN values were 0.15 and 0.22% for intensive cereal and agroforestry systems that were taken as low to very low. Similarly the mean values for AP were 8 and 10 mg kg−1 for cereal and agroforestry systems that were rated low. On the other hand, the CEC, exchangeable bases (Ca2+, Mg2+, K+) and PBS of the soil were rated high while Na+ appeared only in trace amount, and there was no significant difference between land use type and slope classes except for Mg2+, K+ and PBS. Mean values of Mg2+ and K+ (15 and 3 cmol(+) kg−1) and PBS (75%) in the agroforestry system were significantly higher than those in the cereal system (6 and 1.6 cmol(+) kg−1 of Mg2+ and K+ and 51% PBS). Among micronutrients, land use significantly (p < 0.05) affected available Fe2+, Mn2+ and Zn+. The mean values of Fe2+ (97 mg kg−1) and Mn2+ (68 mg kg−1) in the agroforestry system were taken as excessively high while they were moderately sufficient (37, 39 mg kg−1, respectively) in the cereal system. Slope effects were significant for OC, TN and AP having higher mean values (2.5% OC, 0.22% TN and 17 mg kg−1 AP) in the lower slope than in the upper slope (1.5% OC, 0.13% TN and 8 mg kg−1 AP). Land use and slope had significant effect on some soil physical and chemical characteristics. The land use practices in the intensive cereal system are adversely affecting important soil characteristics as compared to the soil under the agroforestry system. These include alteration of particle size distribution, strongly acidic soil reaction, organic matter and nutrient depletion (N, P, K and Zn) and low plant available water content. Among the inappropriate land use practices include repeated cultivation to create fine seedbed that predisposes the soil to erosion, unbalanced fertilizer application, rotation of maize with potato that are depleting soil nutrient stocks (e., K and Zn), and removal of crop residues from fields. Therefore, a more balanced fertilizer blend application that contain N, P, K and Zn combined with liming to raise soil pH, organic matter management and integrated soil water conservation are recommended.

Soil fertility depletion is emerging as a serious challenge causing low crop yields and food insecurity in Ethiopia. An on-farm experiment was conducted in 2017/2018 cropping season to investigate the effects of combined application of compost and mineral fertilizer on selected soil properties and maize yield in North-western Ethiopia. Treatments were factorial combinations of three rates of Urea/NPSB (0/0, 50/50 and 100/100 kg ha−1) and three rates of compost (0, 5 and 10 t ha−1). The field experiment was arranged in randomized complete block design (RCBD) with three replications. Results showed that combined application of compost and mineral fertilizer significantly (p < 0.05) increased soil pH, organic carbon (OC), total nitrogen (TN), available phosphorus (AP), available sulphur (AS) and cation exchange capacity (CEC) compared to sole mineral fertilizer application and the control. On the other hand, there was significant (p < 0.01) decrease in soil bulk density. Plots amended with 10 t ha−1 compost and 100/100 kg ha−1 Urea/NPSB provided the highest maize dry biomass (18.62 t ha−1) and grain yield (6.07 t ha−1). Conversely, the lowest biomass (5.70 t ha−1) and grain (1.17 t ha−1) yields were obtained from the control. The partial budget analysis also showed that the highest net benefit (32700 Birr ha−1) was obtained from combined addition of organic and mineral fertilizer which was significantly higher than applying the highest rate of sole mineral fertilizer (27438 Birr ha−1), highest rate of sole compost (9011.3 Birr ha−1) and the control (7660 Birr ha−1). Therefore, we concluded that integrated fertilizer management improves soil properties and crop yield in the highlands of north-western Ethiopia.

Understanding organic carbon accumulations in soils is crucially essential concerning carbon sequestration, fighting climate change, increasing land productivity, improving soil properties, providing energy to the microbial community, enhancing ecological restoration, and reversing global environmental damage. This study was aimed at assessing the effects of land-use-cover change (LULC) on soil organic carbon (SOC), its' stock potential, and bulk-density (BD) along slope position in the Coka watershed. Replicated soil samples had been collected and composited from 30 cm depth topsoil of five major land use types and three slope positions. This result showed that significantly (P < 0.001) lowest and highest mean of soil organic carbon stock (SOCS) was observed under bare lands (37.835 Mg ha⁻¹) and bushlands (144.582 Mg ha⁻¹), respectively which was the same for SOC concentration. Barelands lose 3.82 times (3.82x) higher SOCS than bushland and 2.68x more SOCS than forestland. Both SOC-stock and SOC showed significant (P < 0.001) differences among slope positions, which were the highest in lower-slope followed by middle-slope, which had 1.8 and 2.6x higher than in middle-slope and upper-slope positions, respectively. Thus, the multivariate-test result divulges that LULC along slope positions has a strongly significant (P < 0.05) main and interaction effect on SOCS in the area. Therefore, the potential contribution of bushland and forestland uses should be improved for SOC sequestration, soil productivity improvement, and environmental protection.