Land-use changes under poor management practices are among the major causes of decline in soil fertility and agricultural productivity in south-central Ethiopia. Therefore, the study of soil properties variations across land-use types will have implications for planning proper soil management strategies. This study assessed the effects of land-use types on soil physicochemical properties in the Cheha district, south-central Ethiopia. Seven land-use types, eucalyptus plantation, cultivated, grazing, shrub, enset (Ensete ventricosum), khat (Chata edulis), and natural forest, were considered in describing soil fertility. A total of 21 soil samples (0–20 cm depth) were collected randomly from three representative soil sampling plots across each land-use type and examined for their analysis of soil physicochemical properties. Results showed that land-use changes induced significant (p < 0.05) differences in the soil OC, total N, CEC, pH, aluminum saturation, and Fe among land-use types were observed. Soils under eucalyptus plantation were considerably low in the sand (23.44%), silt (24.00%), and available water content (111.13 mm/m), whereas high in clay (52.56%) content and bulk density (1.39 g cm−3) as compared to enset land-use type. Compared to natural forest, soils under enset land-use type were high in soil OC (2.41%), total N (0.23%), and CEC (37.61 cmol (+) kg−1) followed by khat land-use. Correlation analysis also showed a highly significant positive relationship between soil OC and CEC but negative with bulk density, soil pH, and aluminum saturation. Total N in eucalyptus plantation, cultivated, khat, and enset lands were depleted by 56.0%, 40.0%, 36.0%, and 8.0%, respectively. Relative to forest land, lower exchangeable Ca, Mg, and Na contents were recorded in soils of cultivated land use. The extractable Fe, Mn, and Zn contents of soils were generally high and are not limiting for crop production. The intensive exploitation of land resources and improper soil management systems in the area could be the major factors for variations in soil properties across land-use types. Therefore, there is a need to develop integrated soil management practices that could help to restore soil nutrients and thereby minimize the continuing soil degradation for sustainable agricultural productivity.

The study was carried out to evaluate the productivity of maize-soybean intercropping system and to identify the best combination that maximize productivity of the system. Maize hybrid (BH540) at 44,444 plants ha-1 and three soybean varieties (AFGAT, Awassa-95 and Crawford) in a factorial combination of three planting densities (25%, 50% and 75%) of the recommended population density of soybean with the respective sole of each variety of component crops were arranged in a randomized complete block design with three replications. Sole cropped maize grain yield (3189.80 kg ha-1) was non-significantly greater than intercropped (2753.70 kg ha-1) by means of 13.67%. Soybean seed yield of 1993.61 and 747.48 kg ha-1 was obtained from sole and intercropped soybean, respectively. In all combinations, LER was greater than one justified that a yield advantage of (14-32%) and (6-28%) as depicted by LER 1.14-1.32 and 1.06-1.28 due to varieties and planting densities, respectively. Generally, as LER was superior in all intercrops evaluating that the productivity of maize-soybean intercropping showed a higher relative yield advantage of 32% over sole cropping. The GMV of the intercrops was increased with an increase in planting density of soybean. Furthermore, the GMV of intercrops (ETB 12176.00 per ha) was greater by means of 41.05% over sole cropped maize whilst lower than that of soybean sole cropped GMV by ETB 3772.90 per ha or 23.66%. However, MA had not significantly varied due to varieties and planting densities and cropping system. In additive intercropping system, maize intercropped with Awassa-95 at 50% planting density showed a yield advantage of 23.71% over sole cropped maize.