ORIGINAL ARTICLE The role of Chomo grass (Brachiaria humidicola) and exclosures in restoring soil organic matter, total nitrogen, and associated functions in degraded lands in Ethiopia Shimeles Damene 1 & Asmamaw Bahir 2 & Grace B. Villamor 3 Received: 29 August 2019 /Accepted: 22 June 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Establishment of native plant species on degraded environments, followed by a period of exclosure, is a practice increasingly used in southwestern parts of Ethiopia for land restoration and soil and water conservation purposes. To assess its effectiveness, and the complementary benefits of combining establishment of Chomo grass (Brachiaria humidicola) with land exclosure for restoration of degraded lands have been studied. Soil samples were collected in two soil depth (0–10 cm and 10–30 cm) from open sites, from 4-, 8-, and 15-year-old exclosures, and three different land cover types (open land with bare soil, grasslands, and wood/bush lands). Soil organic carbon (SOC) and total nitrogen (TN) increased in open land with bare soils to 15 years old and wood/bush land-based exclosures. The mean SOC in wood/bush land-based exclosure soils was 16.4 t ha -1 and 26 t ha -1 higher than grasslands and bare lands, respectively. The protection of degraded lands from direct animal interference coupled with establishment of Chomo grass appears to be effective in restoring SOC and TN. Therefore, the exclosure and Chomo grass sowing practices and functions have improved vegetation recovery, soil fertility, and water retention capacity. In addition to the restoration enhancement effect of Chomo grass, the grass has been used as the source of livestock feed through cut-and-carry system by the local community. Therefore, integration of exclosure with ecologically adaptive Chomo grass planting appears to enhance the restoration of degraded lands and may bring the land back to its previous better status for livestock feed and crop production. Keywords Brachiaria humidicola . Degradation . Exclosure . Soil organic carbon . Restoration . Total nitrogen Introduction Environmental resource degradation of developing countries can be summarized using biological, economic, and technological metaphors (Hecht, 1995). In the biological metaphor, two centuries ago, Malthus poignantly stated that environmental re- source depletion is a consequence of fast population growth (Malthus 1798). The rapid growth of population leads to high demand and over exploitation of resources beyond resources carrying capacity that gears to the ramification of degradation as experienced in much of Southern Asia, Sub-Saharan Africa, and the Andean countries among others (Blaikie and Brookfield 1987; Barret 1996; Jones and Hollier 1997). With respect to an economic perspective metaphor, the faulty property relation of common resource such as grazing and forest lands and the profit- oriented land development all play significant roles in the envi- ronmental resource degradation in developing countries. Hardin (1968), for example, indicated that in common resources, each economic actor seeks to maximize his individual utility and ben- efits through further resource exploitation, while the costs of environmental resource degradation are shared among all mem- bers of the society as a whole. Economic growth and develop- ment are generally accompanied by increased use of natural Communicated by Anne Bousquet-Melou * Shimeles Damene shimelesdamene@yahoo.com 1 College of Development Studies, Addis Ababa University, Addis Ababa, Ethiopia 2 Department of Geography and Environmental Studies, Addis Ababa University, Addis Ababa, Ethiopia 3 Centre for Resilient Communities, University of Idaho, Moscow, ID, USA Regional Environmental Change (2020) 20:92 https://doi.org/10.1007/s10113-020-01680-z