2021/07/22 by Fantaw Yimer, Yimer, Fantaw
Arts and Humanities · Health Professions · #Hermeneutics and Narrative Identity #Aging, Elder Care, and Social Issues #Health, Medicine and Society
paper · doi:10.20372/230amn42
This study addressed the effects of landscape positions on morphological, physicochemical properties of soils in the Main Rift Valley of Ethiopia. Three landscape positions: upper, middle and lower; and three profile horizons: A, B and buried Ab were considered along a transect line. Nine soil profiles; three in each landscape position, were opened, described and samples collected from each of the observed diagnostic horizon and analyzed. The average thickness of the A- horizon was 34 cm in the upper, 10 cm in the middle and 50 cm in the lower landscape positions. Gravels and high sand fractions (average, 41.4%) dominated the B-horizons, indicating the low rate of weathering. The clay fractions and soil bulk density (p<0.001), available water capacity (AWC) (p=0.050), soil organic carbon (SOC) and total N (p= 0.004 and 0.025, respectively), Available P (p=0.004), Exchangeable Ca2+ (p=0.019) and CEC (p=0.010) varied significantly with horizons. Landscape positions also influenced the textural fractions of clay, bulk density, AWC, SOC, total N, available P, exchangeable Ca2+ and CEC. However, the SOC concentration across the profiles were low due to the combination of lower inputs because of less biomass return on harvested land, increased aeration by tillage and crop residue collection for fire. The low available P might be due to the high P-fixation behavior of andosols. Continuous cultivation without appropriate soil management practices has resulted in more complex and non-systematic patterns of soil nutrient distribution. Thus, landscape level management practices are required to replenish soil nutrients for sustainable agriculture.