Exposure to fluoride beyond the recommended level for longer duration causes both dental and skeletal fluorosis. Thus, the development of cost-effective, locally available, and environmentally benign adsorbents for fluoride removal from contaminated water sources is absolutely required. In the present study, diatomaceous earth (diatomite) locally available in Ethiopia, modified by treating it with an aluminum hydroxide solution, was used as an adsorbent for fluoride removal from aqueous solutions. Adsorption experiments were carried out by using batch contact method. The adsorbent was characterized using FT-IR spectroscopy. Effects of different parameters affecting efficiency of fluoride removal such as adsorbent dose, contact time, initial fluoride concentration, and pH were investigated and optimized. The optimum adsorbent dose, contact time, initial fluoride concentration, and pH values were 25 g/L, 180 min, 10 mg/L, and 6.7, respectively. The performance of the adsorbent was also tested under optimum conditions using groundwater samples taken from Hawassa and Ziway. Langmuir and Freundlich isotherm models were applied to describe the equilibrium data. Compared to Langmuir isotherm (R² = 0.888), the Freundlich isotherm (R² = 0.985) model was better fitted to describe the adsorption characteristics of fluoride on Al-diatomite. The Langmuir maximum adsorption capacity was 1.67 mg/g. The pseudosecond-order model was found to be more suitable than the pseudofirst-order to describe the adsorption kinetics. The low correlation coefficient value ofR² = 0.596 for the intraparticle diffusion model indicates that the intraparticle diffusion model does not apply to the present studied adsorption system. The maximum fluoride removal was observed to be 89.4% under the optimum conditions which indicated that aluminum hydroxide-modified diatomite can be used as efficient, cheap, and ecofriendly adsorbents for the removal of fluoride from contaminated water.

Coffee forests are the most valuable land-use systems that provide multiple benefits such as biodiversity conservation, carbon sequestration and source of income. This study aimed to estimate the carbon stock of coffee agroforestry systems and the contribution of coffee plants (Coffea arabicaL.) to carbon sequestration in the entire coffee agroforestry systems in southwestern Ethiopia. The carbon stock in trees was estimated by field-based measurements and allometric equations, whereas the carbon stocks in litter and soil were determined using field sampling and laboratory analysis. The carbon stocks of the coffee agroforestry systems in the study site ranged from 254.9 t C/ha in the Syzygium-shaded coffee forest to 321.8 t C/ha in the Albizia-shaded coffee forest. The overall mean carbon sequestration in the present coffee agroforestry systems was 287.1 t C/ha. The net carbon sequestered by coffee plants in the agroforestry systems ranged from 18.8 t C/ha in the Syzygium-shaded coffee stratum to 48.5 t C/ha in the Albizia-shaded coffee stratum. This demonstrates that Albizia is the most compatible shade tree for coffee plants. On average, coffee plants contributed 37.5 t C/ha, accounting for approximately 12.8% of the total carbon sequestered in the coffee agroforestry systems. Hence, we recommend coffee forests for all-in-one benefits such as climate change mitigation, sustainable landscape management and income generation.

Assessment of the Severity of Acid Saturations on Soils Collected from Cultivated Lands of East Wollega Zone, Ethiopia

Poor soil fertility status and inappropriate agronomic practices are the major factors for low crop productivity like legumes. Thus, the experiment was conducted to evaluate the effect of the P fertilizer rate and rhizobium inoculation on selected soil properties and yield of faba bean. In order to achieve this objective, a field experiment was laid out in a randomized complete block design in a factorial arrangement with replication. The treatments consisted of five P levels (0, 23, 46, 69, and 92kg P₂O₅ ha⁻¹) and two rhizobium inoculants (Fb₁₇ and Fb₁₈). Faba bean (Moti variety) was used as the test crop. Soil samples were collected before and after planting for laboratory analysis. All soil and agronomic data were subjected to the analysis of variance (ANOVA) using statistical analysis software version 9.2. The main effect of strain positively improved soil porosity, but soil bulk density was negatively influenced. Soil chemical parameters such as organic carbon, total N, available P, available sulfur, Ca, Mg, and K were positively influenced. The interaction effects of the P fertilizer rate and rhizobium inoculation significantly influenced organic carbon, total N, available P, and yield parameters (pod per plant, numbers of nodules per plant, biomass yield, straw yield, and grain yields). The combined application of 69kgP₂O₅ ha⁻¹ and Fb₁₈ rhizobium inoculants gave the highest grain yield (4.4t ha⁻¹) of faba bean. Thus, the integrated application of strain and P₂O₅ fertilizer improved soil fertility and faba bean crop yield. Therefore, reducing soil fertility constrains of the soils through the integrated application of strain and P₂O₅ fertilizer could be a possible option to reduce the yield gap seen between smallholder farmers and experimental fields. So as to maintain soil fertility and sustain faba bean crop production, farmers of the study area are advised to make integrated use of strain type Fb₁₈ and P₂O₅ fertilizer at 69kg/ha⁻¹ with appropriate agronomic practices.

Soil acidity is one of the most serious constraints limiting crop productivity in regions with high rainfall in Ethiopia. To address this issue, field experiments were conducted during the 2024 main cropping season in farmers’ fields in two distinct ecological locations. This study aimed to explore the response of soil chemical properties and wheat (Triticum aestivum L.) to organic and inorganic amendments of acidic soils in Jaldu district and Cheha district in central Ethiopia. Application rates of 0, 2.5, 5, and 7.5 t/ha vermicompost; 0, 2, 4, and 6 t/ha agricultural lime; and 0, 50, 100, and 150 kg/ha NPS fertilizer were applied to acidic soils of the study areas. Soil chemical properties related to acidity were determined using standard laboratory procedures, which indicated low pH, available phosphorus (P), organic carbon (C), total nitrogen (N), total exchangeable bases, and cation exchange capacity, along with high exchangeable acid before planting. After harvesting, agricultural lime improved acidity-related soil conditions, including pH, organic C, available P, and total exchangeable bases, while reducing exchangeable acids in both districts. Vermicompost specifically improved soil organic C and total N in the soil of Jaldu district. The improvement in soil acidity due to liming was greater than that achieved by vermicompost or NPS fertilizer. Wheat yield increased in response to all rates of agricultural lime, vermicompost, and NPS-fertilizer applications. The highest yields of 5.71 t/ha and 4.62 t/ha were obtained with the application of 6 t/ha of agricultural lime in Cheha district and Jaldu district, respectively. The study demonstrated that sustainable agricultural practices soil amendment with agricultural inputs decreases soil acidity and improve wheat grain yields. Locational disparities in soil physical–chemical properties and wheat production with limited amendment options can limit the applicability of the findings from the selected study districts to wider regions. Therefore, investigations over diverse locations, seasons, and wheat varieties are needed to examine the effects on soil fertility and crop yield returns, and the economic viability of using diverse agricultural inputs.

Land is a non‐renewable resource that has a finite quantity, and efficient use of this resource is imperative for food security, development, and adaptation to climatic change. In this regard, land suitability analysis is a fundamental decision‐support system that ensures the allocation of this resource for an optimal production agenda while sustaining a clean environment. The research aims to address the important gap in site‐specific information on land suitability for the production of sugarcane ( Saccharum officinarum L.) in Ethiopia, a major factor underpinning poor performance in terms of output despite heavy investment. Working with the Food and Agriculture Organization methodology of land evaluation, this research was conducted to examine the physical suitability of lands for growing sugarcane in the area covering Arjo‐Dhidhesa Estate Sugar Factory in Western Ethiopia. Land suitability evaluation was conducted using the minimum–maximum constraint method in the ArcGIS mapping tool. Land mapping units (LMUs) were identified based on topography, soil depth, texture, and morpho–physico–chemical properties, and then evaluated against sugarcane requirements. Additionally, agro‐climatic information for the 1983–2022 period was evaluated. The analysis shows that agro‐climatic factors in this region support a level of “high suitability” (S1) for sugarcane, but soils bring in some degree of restriction in different LMUs. The LMU 1Ahc and 1Cc showed a degree of “moderate suitability” (S2) restriction based mainly on acidity and shallowness of soils, respectively. However, LMU 3Ahc and 2Bscl were “marginally suitable” (S3) based mainly on low content of organic carbon (C), total nitrogen (N), and available phosphorus (P). Topography, drainage, and millability constraints had minimal impact and did not significantly limit suitability in any of the LMUs. As this research finds, despite climatic suitability, using this site‐specific methodology in soils to alleviate different physical and chemical restrictions may have a major role in ensuring sugarcane sustainability in this region through a balanced application strategy in soils.