Conservation Effects on Soil Quality and Climate Change Adaptability of Ethiopian Watersheds

Abstract

This study analyzes effects of soil and water conservation (SWC) on soil quality and implications to climate change adaptation and mitigation in the Upper Blue Nile River Basin of Ethiopia by using the Anjeni watershed as a case study site. Disturbed and undisturbed soil samples were collected from two sub-watersheds of Anjeni: the Minchet sub-watershed (with SWC measures) and the Zikrie sub-watershed (without SWC measures). Soil samples were taken from 30-cm depth from five representative landscape positions and analyzed following the standard soil lab analysis procedures. The results show that soils from the conserved sub-watershed had improved quality indicators compared with those from the non-conserved site. Significant improvement due to SWC measures was observed in the soil hydrological [total moisture content (+5·43%), field capacity (+5·35%), and available water capacity (+4·18%)] and chemical [cation exchange capacity (+4·40 cmol(+) kg À1 ), Mg 2+ (+1·90 cmol(+) kg À1 ), Na + (+0·10 cmol(+) kg À1 )] properties. SWC interventions significantly reduced soil erosion by 57-81% and surface runoff by 19-50% in the conserved sub-watershed. Reduction in soil erosion can maintain the soil organic carbon stock, reduce the land degradation risks, and enhance the C sequestration potential of soils. Therefore, adoption of SWC measures can increase farmers' ability to offset emissions and adapt to climate change. However, SWC measures that are both protective and sufficiently productive have not yet been implemented in the conserved sub-watershed. Therefore, it is important that SWC structures be supplemented with other biological and agronomic measures in conjunction with soil fertility amendments appropriate to site-specific conditions.

Interrelationships between terrace development, topography, soil erosion, and soil dislocation by tillage in Minchet Catchment, Ethiopian Highlands

“…The mean precipitation is 1,690 mm/yr, concentrated from May to October (Bayabil, Tebebu, Stoof, & Steenhuis, 2016). In Minchet Catchment, the soils developed Soil surveys of the study area in 1984, 1997(Kejela, 1995Mengistu, Bewket, & Lal, 2016;Zeleke, 2000) showed slight changes in selected soil chemical properties, such as pH, total nitrogen, cation exchange capacity, available phosphorus (P), and soil organic carbon. Even though these studies included all the representative soil types, the sampling points were slightly different for each soil survey.…”

Exploring the scaling-up of sustainable land management in the Central highlands of Ethiopia

“…The problem of land degradation is particularly persistent in the highlands of Ethiopia, where the majority of the country's population lives and depends on farming (Amsalu & de Graaff, 2007;Mengistu et al, 2015;Adego et al, 2018). The Ethiopian highlands cover about 65% of the total area of the country, 90% of its arable lands, house 90% of the human population and 60% of the livestock population (Hurni et al, 2010).…”

“…Changes in rainfall and temperature enhance the probability of crop failures and the proliferation of weeds and insects, to eventually reduce crop yields (Araya & Stroosnijder, 2011;Liniger et al, 2011) and food availability (Adimassu et al, 2014;. In addition, recurrent drought and erratic rainfall distribution have adverse effects on soil productivity and soil water holding capacity for crop production (Mengistu et al, 2015). The core argument of this research is that Sustainable Land Management (SLM) is required in Ethiopia to reverse the problem of land degradation and increase the country's economic growth and food security.…”

Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards

“…1) (Bisantino et al, 2015;Keesstra et al, 2016;Novara et al, 2016;Prosdocimi et al, 2016c). However, to reduce the high soil erosion rates, more conservation-minded soil management practices have also been used such as mulching (Cerdà et al, 2015;Costantini et al, 2015;Jordán et al, 2011;Prosdocimi et al, 2016bProsdocimi et al, , 2016c, cover crops (Novara et al, 2011), rock fragments (Blavet et al, 2009), natural grassing (Grimaldi et al, 2015;Mekonnen et al, 2015a;Mekuria et al, 2016;Raclot et al, 2009) and geotextiles (Giménez Morera et al, 2010;Mekonnen et al, 2015b;Mengistu et al, 2016). Furthermore, new approaches to evaluate incentives for the adoption of agri-environment measures in degraded and eroded vineyards have been implemented (Galati et al, 2015) and mulching is one of those successful strategies (Prosdocimi et al, 2016c).…”