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Due to continuous cultivation, high soil acidity, and low nutrient inputs, soil fertility depletion has been a major threat to northwest Ethiopia's crop productivity and food security. This study aimed to examine the effects of vermicompost and lime rates on soil properties and malt barley (Hordeum distichum L.) productivity under a furrow irrigation system on acidic soil in the Mecha district, northwest Ethiopia. The treatments were combinations of three levels of vermicompost (0, 2.66-, and 5.31-tons ha-1) and three levels of lime (0-, 2.16-, and 3.24-tons ha-1) arranged in a randomized complete block design with three replications. The results showed that the integrated application of 5.31 tons of vermicompost and 3.24 tons of lime ha-1 provided the highest soil pH (6.20), available phosphorus (8.55 mg kg-1), total nitrogen (0.25%), and organic carbon (3.40%). On the other hand, adding vermicompost and lime in combination or separately noticeably decreased the exchangeable acidity and aluminum toxicity. Besides, the integrated application of 5.31 tons vermicompost (VC) and 3.24 tons lime (L ha-1 provided the highest dry biomass (12.22 tons ha-1), grain yield (5.30 tons ha-1), and net benefit (197, 246 Ethiopian Birr (ETB). Overall, the integrated application of vermicompost and lime can substantially increase soil fertility and crop yields. However, this study needs further testing and validation at varied rates in other areas. [ABSTRACT FROM AUTHOR]

Soil fertility depletion has significantly reduced the yields of various crops in Ethiopia, mainly the yield of malt barley in the district. To address this issue, integrated applications of vermicompost and mineral nitrogen (N) fertilizers were tested. Therefore, this study aimed to evaluate the effects of vermicompost and mineral nitrogen fertilizers application on malt barley yield (Hordeum distichum L.), soil properties, and economic benefits. The experiment was arranged in a randomized complete block design with three replications. The treatments were nine in various combinations of vermicompost (VC) and N fertilizer (N): (69 kg N; 0.79 t VC + 58.65 kg N; 1.59 t VC + 48.30 kg N; 2.39 t VC + 37.95 kg N; 3.19 t VC + 27.60 kg N; 3.98 t VC + 17.25 kg N; 4.78 t VC + 6.90 kg N; 5.31 t VC ha−1 and control). The highest soil pH was recorded by applying 5.31 t of vermicompost ha−1 alone. The highest total nitrogen (0.34%), available phosphorus (15.58 mg kg−1), grain yield (4950 kg ha−1), and net benefit (4255.74 USD) were recorded from the application of 2.39 t VC plus 37.95 kg N, while the highest soil organic carbon (3.38%) and cation exchange capacity (26.17 cmol (+) kg−1) were recorded from 3.19 t VC plus 27.60 kg N ha−1 compared to the control. This study concludes that applying 2.39 t VC and 37.95 kg N ha−1 in combination improves soil fertility, malt barley yield, and economic benefits for smallholder farmers in the study district and adopts this in similar soil types and agroecologies. Core Ideas: Effects of vermicompost and N fertilizer integration on soil properties, yield, and economic benefits were evaluated.Integrated application of 2.39 t VC and 37.95 kg N ha−1 increased total N, available P, soil organic carbon, and cation exchange capacity.Combined application of 2.39 t VC and 37.95 kg N ha−1 gave 30% yield advantage over 100% recommended nitrogen.Application of 2.39 t VC combined with 37.95 kg N ha−1 N fertilizer generates greater net benefits to farmers. [ABSTRACT FROM AUTHOR]

Soil erosion debilitates soil fertility and agricultural productivity in Ethiopia. Soil and water conservation (SWC) measures have been implemented to address this issue, but their effects have not been evaluated in different parts of the country. This study was therefore conducted to evaluate the effects of SWC structures and slope position on soil properties in the Gelda watershed, northwestern Ethiopia. Core and disturbed composite soil samples were collected at a depth of 0–20 cm from the upper (15–20%), middle (10–15%), and lower (4–10%) slope positions of cultivated fields treated with soil bund (SB), stone‐faced soil bund (SFSB), and stone‐faced soil bund stabilized by Sesbania sesban (SFSBS) and from untreated fields (control). The samples were analyzed by soil analytical techniques. The results revealed that the clay particles, pH, soil organic matter (SOM), total nitrogen (TN), available phosphorus (AvP), cation‐exchange capacity (CEC), and exchangeable Ca2+, Mg2+, and K+ were significantly (p < 0.05) increased, while bulk density (BD) and the sand fractions decreased in SWC‐treated plots. On the lower slope, significantly higher (p < 0.05) clay, silt, pH, SOM, TN, AvP, CEC, and exchangeable bases were recorded, while the upper slope had the highest sand and BD values. The interactions of slope and SWC structures affected the distribution of sand, TN, AvP, exchangeable Ca2+, and Mg2+. The SWC structures implemented in the watershed improved soil fertility, but the impact was stronger when stone‐faced soil bunds were integrated with Sesbania sesban plant species. Therefore, during the implementation of SWC structures, the integration of soil physical structures with plant species aligned with slope positions should be considered, as both factors have an impact on soil fertility improvement and soil erosion in the study area and similar agroecologies. The impacts of SWC structures on crop yield, their economic implications, and environmental benefits for the studied watershed and for the region as a whole need further investigation. [ABSTRACT FROM AUTHOR]

Soil fertility is the controlling factor of agricultural production worldwide including Waghimera zone, Ethiopia. However, it has been diminished from time to time and leads to low crop yield. Measuring of soil nutrient inflow-outflow affords necessary information about the current nutrient status of the soils, and to take appropriate nutrient management practices. The study was conducted to estimate the full soil nutrient balance of cultivated farms in the northern, of Ethiopia, in the 2020/21 main season. Inflow and Outflow of N, P, and K into, and out of farms were measured through the interview, field measurement, laboratory analysis, USLE model, and pedo-transfer functions. The full N balance of barley, tef, and wheat were -66.7, -8.9, and - 47.1 kg ha-1 yr-1, respectively. P full balance was -5.4, 1.4, and -1.9 kg ha-1 yr-1 for barley, tef, and wheat farms, respectively. Whereas, K balance was also -12.4, -3.3, and -6 kg ha-1 yr-1 for barley, tef, a nd wheat, respectively. The balance quantification was done by subtracting nutrient outflows from the inflows. The results revealed that N, P, and K had negative balances except for P in tef. Grain yield and crop residue removal were the major paths of nutrient loss. To sustain, and boost agricultural production, reversing the imbalance between inflows, and outflows is critically essential for the study area. The current highly depleted nutrient should be corrected by adding sufficient organic, and inorganic nutrient sources, like in situ manuring, biochar, green manure, and remaining crop residue in the fields. [ABSTRACT FROM AUTHOR]

Application of biochar on acidic soils may improve soil fertility and crop productivity. This study aimed to explore the relevance of parthenium biochar-induced changes in the physicochemical properties and agronomic performance of the selected wheat varieties in acidic soils. A pot trial was used in determining the effect of slow pyrolysis parthenium biochar on acidic soils and the agronomic performance of wheat varieties. A general linear model (GLM) of multivariate analysis and principal component analysis (PCA) was used to compare functional variation among soil assayed parameters with biochar dosages and years. Biochar-treated acidic soils did not show significant differences in their physical properties. However, a significant incremental trend was observed in the soil moisture content. The biochar-amended acidic soils showed noticeable differences in the soil pH, available phosphorous, and exchangeable bases (Ca, K, and Na) compared to the control. In all soil samples, a decreasing trend in the soil micronutrients was observed with an increase in the biochar amounts. The analysis also unveiled significant changes in root length, root and shoot dry biomass, and plant height of wheat varieties in response to the biochar amendments. The application of 19.5 t/ha and 23 t/ha dosages of biochar gave the maximum changes in the agronomic performance of Kekeba and Ogolcha varieties, while the minimum was obtained in the 26.5 t/ha and the control. Furthermore, PCA axis 1 accounted for 74.34% of the total variance within a higher eigenvector value (10.4076), and most of the soil parameters were positively correlated with CEC (0.29), available phosphorous (0.29), and soil pH (0.28); however, the micronutrients were negatively correlated. In conclusion, Parthenium hysterophorus biochar has the potential to amend acidic soils, and thus, the application of 16.0, 19.5, and 23 t·ha-1 biochar dosages are considered suitable to reduce the soil acidity level and improve the agronomic performance of wheat varieties. However, extensive research will be needed to determine the effects of biochar on soil properties and crop production in field conditions. [ABSTRACT FROM AUTHOR]

Forests in Ethiopian highlands have been degraded by diverse anthropogenic factors. In response to this, exclosures have been implemented widely as a vegetation restoration strategy for decades. However, studies that show the potential of exclosures in restoring degraded forests in the study area are scarce. Here, we evaluate the woody species diversity, structural attributes, and responses of functional traits in dry Afromontane forests of northern-eastern highlands of Ethiopia under varying forest exclosure ages. A systematic transect sampling method was employed to gather woody species data from four treatments, including open woodland (OWL), exclosure for ten years (EX10), twenty years (EX20), and thirty years (EX30). Within each treatment, we sampled from two slope orientations. Diversity, stand attributes and functional traits data were collected from 185 plots, each with a size of 20 m × 20 m, at all study sites. Smaller nested plots were established to account for seedlings and saplings. We used Generalized Linear Mixed-effect Models (GLMMs) to test variation in diversity metrics between slope orientations and forest exclosure ages. Non-metric multidimensional scaling (NMDS) and one-way permutational multivariate analysis of variance (PERMANOVA) were performed to visualize the difference in species composition among forest exclosure ages. Sixty-one woody species belonging to 34 families were identified from OWL, EX10, EX20 and EX30. Species richness (0D) indicated a considerable increasing trend with increasing forest exclosure ages. Shannon diversity index (1D) showed significant differences (p<0.001) among exclosure ages and slope orientations, while evenness and inverse Simpson (2D) were only different within exclosure ages and slope orientations, respectively. EX30 had the highest Shannon diversity (1D), while OWL had the lowest. The study found that species composition increased with forest exclosure ages, with higher species similarity observed between EX20 and EX30. Our results showed that exclosure treatment substantially (p<0.05) increased woody species density, basal area, seedling density, and sapling density. However, the variation in diameter at breast height (DBH) among exclosure ages was insignificant. According to the DBH distribution, an inverse-J shape pattern was found across all forest exclosure ages, indicating a healthy regeneration status. Juniperus procera and Dodonaea angustifolia had high importance values (IVI) in exclosure areas. Despite their insignificant variation, most functional traits showed an increasing trend with increasing exclosure ages. In general, the study highlights that exclosures can enhance ecosystem restoration in degraded landscapes and thus offers crucial insights for forest management in other areas by prioritizing biodiversity hotspots and threatened species. • Exclosure ages on woody diversity, structure and functional traits were quantified. • Exclosure ages were shown to enhance richness, diversity and stand attributes. • North-facing slope affected diversity, while the south-facing slope influenced evenness. • We found no significant variation in functional traits with increasing exclosure ages. • Expert-based forest management strategies are crucial for ensuring ecosystem benefits. [ABSTRACT FROM AUTHOR]

Qimbaba, a prioritized forest area in the northwest of Ethiopia. However, it is experiencing deforestation that limits restoration possibilities. Hence, a detailed assessment of soil seed bank composition and regeneration potential could permit to improve the management of the forests. The study aimed at comparing native with plantation relative to the soil seed bank, as well as their effect on soil properties. A total of 40 circular sample plots (314 m2) were established, half in the natural and half in the plantation forests. Aboveground vegetation was recorded in each plot. Samples were collected for the soil seed bank analysis in the litter layer and the top 9 cm of the soil (3 cm layers) and for soil analysis down to 30 cm (15 cm depths). Vegetation and soil seed bank composition were compared and the effect of forest type (natural vs plantation) on soil seed bank and soil physical and chemical parameters was evaluated. A total of 14 plant species (11 families) were recovered from the soil seed bank (12 species in the natural and 7 in plantation forest). The soil seed bank was not similar according to the Sorenson's similarity values. There were 11,022 and 10,667 seeds/m2 in the soil seed bank of the natural and plantation forest, respectively. There was no significant difference between the two forests in bulk density, CEC and P but SOC, N, and K were significantly higher in natural. Plantation forest pH was significantly lower than the natural forest. [ABSTRACT FROM AUTHOR]

Application of biochar on acidic soils may improve soil fertility and crop productivity. This study aimed to explore the relevance of parthenium biochar-induced changes in the physicochemical properties and agronomic performance of the selected wheat varieties in acidic soils. A pot trial was used in determining the effect of slow pyrolysis parthenium biochar on acidic soils and the agronomic performance of wheat varieties. A general linear model (GLM) of multivariate analysis and principal component analysis (PCA) was used to compare functional variation among soil assayed parameters with biochar dosages and years. Biochar-treated acidic soils did not show significant differences in their physical properties. However, a significant incremental trend was observed in the soil moisture content. The biochar-amended acidic soils showed noticeable differences in the soil pH, available phosphorous, and exchangeable bases (Ca, K, and Na) compared to the control. In all soil samples, a decreasing trend in the soil micronutrients was observed with an increase in the biochar amounts. The analysis also unveiled significant changes in root length, root and shoot dry biomass, and plant height of wheat varieties in response to the biochar amendments. The application of 19.5 t/ha and 23 t/ha dosages of biochar gave the maximum changes in the agronomic performance of Kekeba and Ogolcha varieties, while the minimum was obtained in the 26.5 t/ha and the control. Furthermore, PCA axis 1 accounted for 74.34% of the total variance within a higher eigenvector value (10.4076), and most of the soil parameters were positively correlated with CEC (0.29), available phosphorous (0.29), and soil pH (0.28); however, the micronutrients were negatively correlated. In conclusion, Parthenium hysterophorus biochar has the potential to amend acidic soils, and thus, the application of 16.0, 19.5, and 23 t·ha -1 biochar dosages are considered suitable to reduce the soil acidity level and improve the agronomic performance of wheat varieties. However, extensive research will be needed to determine the effects of biochar on soil properties and crop production in field conditions., Competing Interests: The authors declare that there are no conflicts of interest., (Copyright © 2022 Meseret Muche et al.)