Search

Land suitability assessment plays an important role in identifying biophysical constraints and evaluating potential capacity of land and its sustainable use. Physical land suitability evaluation for irrigation was carried out in the lower Alwero river area of Abobo, western Ethiopia, following FAO methodology for general irrigation farming. The irrigation suitability of five land mapping units (LMUs): 1Ac, 1Bc, 1Ecl, 2Cc and 3Ccl were assessed by considering slope, drainage, top soil texture, sub soil texture, surface stoniness, surface coarse fragments, subsurface coarse fragment, rockiness, depth to solid rock or hardpan, lime, gypsum, electrical conductivity (EC) and exchangeable sodium percentage (ESP). The result revealed that LMU 1Ac, 1Bc and 2Cc, with total area of 22,367.9 ha (83.7%), were moderately suitable (S2). The moderate limiting factors were drainage, top soil texture and subsoil texture. On the other hand, LMU 1Ec1, covering an area of 3,677.6 ha (13.8%) was not suitable (N) for irrigation due to subsurface coarse fragments and depth to solid rock or hardpan. For all LMUs, parameters like lime, gypsum, EC and ESP were not considered as limiting factors.

Assessing land use-induced changes in soil properties are essential for addressing issues of agro-ecosystem transformation and sustainable land productivity. In view of this, a study was conducted to assess the impact of land use/land cover on the physicochemical properties of soils of Abobo area, western Ethiopia. Three adjacent land use types, namely forest, grazing and cultivated lands each falling under four land mapping units (1Ac, 1Bc, 2Cc and 3Cl) were considered for the study. A total of 40 random soil samples (0-20 cm depth) were collected to make three composite samples for each land use type across the land mapping units and analyzed for selected soil physical and chemical properties. The results of the study, on one hand, revealed that soil OM, total N, CEC, PBS and available micronutrients (Fe, Mn, Zn and Cu) contents of the cultivated land was significantly (P < 0.001) lower than the adjacent forest land. For instance, soil OM, total N, CEC, PBS, exchangeable Mg and available micronutrients (Mn, Zn and Cu) contents of cultivated land was significantly lower than the adjacent forest land by 32.98, 33.33, 16.16, 17.81, 21.88, 29.47, 40.05 and 53.92%, respectively. On the other hand, the results of the study revealed that exchangeable cations (Mg, K and Na), PBS and available micronutrients (Fe, Mn, Zn and Cu) contents of the gazing land was significantly (P < 0.001) lower than the adjacent forest land. However, significant differences were not observed between the forests and grazing lands in soil OM, total N, CEC and available P. From the present study, it could be concluded that the soil quality and health were maintained relatively under the forest, whereas the influence on most parameters were negative on the soils of the cultivated land, indicating the need for employing integrated soil fertility management in sustainable manner to optimize and maintain the favorable soil physicochemical properties.