Effects of Soil and Water Conservation Measures on Soil Quality Indicators: The Case of Geshy Subcatchment, Gojeb River Catchment, Ethiopia

Adane Abebe,Asfaw Kebede,Awdenegest Moges,Melku Dagnachew

doi:10.1155/2020/1868792

Abstract

Land degradation is a global negative environmental process that causes the decline in the productivity of land resources’ capacity to perform their functions. Though soil and water conservation (SWC) technologies have been adopted in Geshy subcatchment, their effects on soil quality were limitedly studied. The study was conducted to evaluate the effects SWC measures on soil quality indicators in Geshy subcatchment, Gojeb River Catchment, Ethiopia. A total of 54 soil samples (two treatments–farmlands with and without SWC measures ∗ three slope classes ∗ three terrace positions ∗ three replications) were collected at a depth of 20 cm. Statistical differences in soil quality indicators were analyzed using multivariate analysis of variance (ANOVA) following the general linear model procedure of SPSS Version 20.0 for Windows. Means that exhibited significant differences were compared using Tukey’s honest significance difference at 5% probability level. The studied soils are characterized by low bulk density, slightly acidic with clay and clay loam texture. The results revealed that farmlands with SWC measures had significantly improved soil physical (silt and clay fractions, and volumetric soil water content (VSWC)) and chemical (pH, SOC, TN, C : N ratio, and Av. phosphorus) quality indicators as compared with farmlands without SWC measures. The significantly higher VSWC, clay, SOC, TN, C : N ratio, and Av. P at the bottom slope classes and terrace positions could be attributed to the erosion reduction and deposition effects of SWC measures. Generally, the status of the studied soils is low in SOC contents, TN, C : N ratio, and Av. P (deficient). Thus, integral use of both physical and biological SWC options and agronomic interventions would have paramount importance in improving soil quality for better agricultural production and productivity.

Highlights

Land degradation is a gradual, global negative environmental process and development issue that causes the temporary or permanent decline in the productivity of land resources’ capacity to perform their functions [1]
Measurement of Soil quality (SQ) requires identification of specific “indicators” that can be quantitatively measured over time and compared to reference conditions or judged against some common standards [6]. us, SQ indicators can be defined as those soil properties and processes that have greatest sensitivity to changes in soil function due to the change in land management practices on a short-term bases [7]
In Shomba subcatchment, Mekuria [12] reported that the estimated mean annual rate of soil erosion in cultivated fields was 13.5 Mgha− 1 yr− 1 that accelerates its rate beyond the tolerable level. e governmental and nongovernmental institutions have been investing huge financial and labor resources to tackle land degradation in Geshy subcatchment, Gojeb River Catchment of Ethiopia

Summary

Introduction

Land degradation is a gradual, global negative environmental process and development issue that causes the temporary or permanent decline in the productivity of land resources’ capacity to perform their functions [1]. Soil quality (SQ) is defined as “the capacity of a specific kind of soil to function within natural or managed ecosystem boundaries to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation” [2]. Research findings revealed that the rate of soil erosion on cultivated lands across the country was 42 Mgha− 1 year− 1 [13]. Various soil and water conservation (SWC) technologies have been adopted and constructed in cultivated fields and the afforestation of hillsides by sustainable land management program (SLMP) under Ministry of Agriculture. Improved land management practices like SWC have been suggested as a key strategy to reduce land degradation and sustain soil quality [17, 18]

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Results