EFFECT OF SOIL CONSERVATION PRACTICES ON SELECTED PHYSICO-CHEMICAL PROPERTIES OF SOILS IN UWITE WATERSHED, HADERO TUNTO DISTRICT, SOUTHERN ETHIOPIA

Abstract

Soil is invaluable natural resource, meeting the basic necessaries of life for mankind. Its degradation due to ever increasing anthropogenic influences is, however, threatening food security and quality of the environment in many regions. The present investigation was, therefore, initiated with an objective of assessing the effect of soil bund (SB) and fanya juu terraces (FT), compared to no conservation practice (NC), on physicochemical properties of cultivated soils of Uwite watershed in Hadero Tunto Zuria District of the Southern Region of Ethiopia. Soil sampling sites were selected both from the farm fields where soil conservation structures were raised and from fields where there was no conservation practice. A total of 18 composite soil samples (3 soil conservation practices x 3 replications x two soil depths (0-15 cm and 15-30 cm) were collected for laboratory analyses and the data was subjected to analysis of variance using the two-way ANOVA by RCBD with factorial arrangement. The survey questionnaires were prepared to gather information on farmers’ perception towards usefulness of SWC measures. Among 425 total households in the study area, only 80 farmers were selected for interview based on systematic random sampling techniques. The collected soil samples were analysed for soil particle size fractions, BD (g/cm3), TP (%), SMC (%), pH(H2O), Ex.A, EC, SOM (%), TN (%), C/N ratio, Avail.P (mgkg-1), Avail.S (mgkg-1),SMC (%), pH(H2O), Ex.A, EC, SOM (%), TN (%), C/N ratio, Avail.P (mgkg-1), Avail.S (mgkg-1), PBS (%), CEC (cmol(+)/kg),Ca+2, Mg+2, K1, Na+ and micronutrients following standard laboratory analysis. The results indicated that soils under SB and FT had significantly better soil texture, bulk density, soil moisture content and total porosity than did the soil under NC. Likewise, the chemical properties viz., pH, soil organic matter content, exchange acidity, cation exchange capacity, percent base saturation and nutrient contents (total N and available P, K, Ca, Mg, S) were significantly improved under SB and FT compared to NC. It was, therefore, concluded that adoption of mechanical soil conservation practices like SB and FT could improve the physical and chemical attributes of soils of degraded cultivated lands of Uwite watershed. The 75 % farmers of the area had a positive outlook, based on the questionnaire survey. However, further studies are required to verify the soil fertility gains under soil conservation practices in terms of increasesin crop yield and overall profit.