Perennial monocropping of khat decreased soil carbon and nitrogen relative to multistrata agroforestry and natural forest in southeastern Ethiopia

Abstract Monocropping of perennial cash crops providing livelihood for smallholders is replacing native forest throughout the tropics, but there no direct empirical evidence on impact soil organic carbon (SOC) and nitrogen (N) relative to multistrata-agroforestry-based cropping. In particular, conversion forests cropping a rapidly expanding monocropping khat ( Catha edulis Forskal) not known. We investigated potential integrated in multistrata agroforestry alleviate SOC N loss from converted forest, monocropping. assessed empirically stocks 40-cm-deep surface layer three matched adjacent plots agroforestry, monocropping, within nine replicate groups land uses. The fixed mass method was applied. estimated rates annual losses were 3.0 3.4 times greater, respectively, areas than systems producing both coffee Coffea arabica ) khat. Additionally, contents leaf litter fine roots greater results indicated that maintains most lost agroforestry-based This warrants economic incentives prevent current stocks, while enabling crop income by smallholders. Reducing stock decline through system management deserves attention as well.