Potential of area exclosure in restoring soil nutrient: Case study from Tigray Region, Northern Ethiopia

Abstract

Area exclosure is a type of land management, implemented on degraded land to address soil and vegetation cover loss, and low water holding capacity of degraded lands for environmental restoration and socio-economic benefit. The present study investigated how exclosure age have an effect on restoration of soil nutrient stocks and properties in Tigray, Ethiopia. Area exclosures of 10, 15, and 20 years old were selected and each exclosure was paired with an adjacent free grazing land. A total of 120 quadrants were sampled using a stratified preferential sampling design technique with flexible systematic model. Pairwise comparisons, Tukey's HSD (Honestly Significant Difference) test, paired t-tests and Pearson correlation tests were conducted to see for significant differences between each category of exclosures duration and the adjacent free grazing lands. Statistical tests were conducted to see the normal distribution of the population and homogeneity of the variance. There was a significant difference (P<0.05) for stone cover, grazing, EC, soil organic carbon, and N among the different aged area exclosures and free grazing lands. There was no significant difference (P>0.05) between similar aged area exclosures or free grazing areas. However, sand, silt, clay, CEC, pH, BD, K, P, Mg, and Ca did not show significant differences. This study has therefore, demonstrated that area exclosures on degraded free grazing lands is found to be an effective way of land restoration by improving soil nutrient content and soil properties.

Key words/phrases: Area exclosure, Free grazing, Land restoration, Soil nutrient, Tigray.