A study was conducted to determine the effect of different land use systems on soil physical and chemical properties in Sodo Zuria Woreda of Wolaita zone Southern Ethiopia. Differences in soil properties in different land use types at two depths (0-15 and 15-30 cm) were observed on many soil properties important to crop growth. Enset (Ensete Ventricosum) fields had higher pH, electrical conductivity (EC), available P and Zn, exchangeable Ca and K which is attributed due to the addition of manure, whereas maize fields had lowest average K and Mg, cation exchange capacity (CEC), percentage of base saturation (PBS), total N and OC. These results suggest that land use has persistent, multi-decadal effects on the spatial heterogeneity of soil resources and also the need of land use and landscape research to determine ecologically sound and sustainable land use and management strategies.

Crop response to phosphorus (P) application is often erratic in most acidic soil types. The main processes for P losses from agricultural fields are fixation, crop removal, erosion, surface runoff, and subsurface leaching. The purpose of this experiment was to evaluate adsorption properties of selected soils, determine the external phosphorous requirements (EPRs) of the soils, and identify factors contributing to P sorption in two soils in North Ethiopia. In this experiment, separately weighed 1 g soil samples were equilibrated with KH2PO4 at rates of 0.5, 5, 10, 20, 30, 40, and 50 mg PL−1. The P sorption data were fitted well with both Langmuir and Freundlich models with average r2 values of 0.91 and 0.88, respectively. The adsorption maximum (Xm) of the Langmuir isotherm ranged from 588.20 mg P kg−1 soil in Luvisols to 833.3 mg P kg−1 soil in Nitisols. The EPRL values ranged between 86.20 to 93.28 mg P kg−1 for soils of the study area. Among the soil properties, clay content and Ex. Al were positively correlated with Xm. The path analysis revealed that clay, pH, and Av. P had a direct effect on P sorption parameters. The EPRL of the studied soils was 3.44 to 3.6 times greater than the blanket P fertilizer rate recommendation. It is concluded that P sorption models can effectively be used to discriminate soils based on P fixation ability. The result further indicates that the current P fertilizer application rate of 50 kg P ha−1 being practiced across all soil types should be revised after validating the models and EPR values estimated in this study for each soil both under greenhouse and in-the-field conditions.

Background: Phosphorus (P) availability is commonly assumed to limit productivity in many tropical soils, yet there is relatively little information on the phosphorus chemical forms, distribution, and transformations that P undergoes in Ethiopian soils. We used a sequential fractionation scheme to assess phosphorus fractions of acid soils of Southern Ethiopia. The study area called Hagereselam is characterized by high soil acidity, and the availability of P in the study area is relatively low. As crop production in Ethiopia is dominated by low external input practices, native P remains the main contributor to plant P nutrition in many locations.Result: Although the total P concentration is 829.7 mg kg −1 , the organic P content was relatively low (58 mg kg −1 ) and constituted on average less than 7% of the total P. The ratio of organic carbon to organic P was generally greater than 240, suggesting the potential for immobilization of P. The Al + Fe-associated P was the dominant inorganic P pool. The majority of the P occurred in recalcitrant form (568.3 mg kg −1). Readily available, exchangeable phosphate, as extracted by anion-exchange resin membranes, was present in very low concentrations (3.3 mg kg −1 ); moreover, labile P accounted for less than 2% (9.9 mg kg −1 ) of the total soil P. Conclusion:Lime was used as a reclamation material for acid soils, and the application of lime significantly affected the different P fractions and was involved in the transformation of P fraction. Organic P forms were significantly lower for higher levels of lime application, suggesting that lime amendment enhanced organic P decomposition. Moreover, application of lime increased Ca-P and decreased Al + Fe-P for acid soils.

Despite the ecosystem functioning they provide, termite pedoturbation along toposequence is overlooked in the genesis of semiarid soils. Therefore, we aimed to describe morphological and physicochemical properties that lead to the classification of termite-mediated soils. In this study, representative pedons, one on each slope class, were described and classified for five different topographical positions, and the soil properties of genetic horizons were compared to those obtained from respective mounds. The result showed that the soils were heavily manipulated by termites except for the pedon at the toe slope. Cambisols were formed on the summit and back slope and resulted from slow pedogenic processes. Luvisols on the toe slope showed redoximorphic features, and gleization and clay synthesis formed the soil, while the upward movement of coarse particles enhanced textural differentiation. Luvisols at the foot of the slope are formed by the partial destruction of iron-bearing minerals accompanied by eluviation-illuviation processes. Accumulation of calcium carbonate following calcification formed Calcisols on the bottom slope. Comparing the mounds and reference pedons, much of the mound’s soil is mined from the subsoil, usually from B horizons. However, their influence on soil properties depended mainly on the topography. Moreover, the morphological and physicochemical properties of the studied pedons exhibited various degrees of variation along topography and clearly showed topographic effects. In conclusion, termites can be a potent mediator of soil genesis across toposequences, and their activities should be considered in the classification and management of semiarid soils. A further retrospective examination of micromorphological evidence is recommended to support this finding.

Integrated nutrient management, which primarily involves the combined application of organic and inorganic nutrient sources, is one of the simplest approaches to handle declining soil fertility challenges and increase crop productivity and production. Keeping in view this fact, a pot experiment was conducted to evaluate the effects of compost and inorganic nitrogen fertilizer and their mixture on soil properties, growth, and nitrogen uptake of maize on loam and clay textured soils at the Awada Agricultural Research Subcenter. Treatments comprised factorial combinations of five compost rates (0, 5, 10, 15, and 20 t·ha−1) and four rates of inorganic nitrogen fertilizer (0, 46, 92, and 138 kg·N·ha−1) laid out as a completely randomized design with three replications. Results showed that both the main and interaction effects of compost and mineral N fertilizer rates significantly affected the selected soil chemical properties and yield, and nitrogen concentration of maize. There were significant associations between plant parameters and soil nitrogen contents. The addition of 92 kg·ha−1·N + 10 t·ha−1 compost and 46 kg·ha−1·N + 10 t·ha−1 compost was the best treatments for loam and clay textured soils of the study areas, which improved shoot dry matter by 179.5 and 284.5%, compared to the unfertilized pot, respectively. From the results of this experiment, we concluded that the integrated application of compost and mineral nitrogen fertilizer enhanced soil chemical properties and thus improved nitrogen uptake and sustainable production of maize in the study areas.