Understanding Spatial Patterns of Soils for Sustainable Agriculture in Northern Ethiopia's Tropical Mountains

PLoS One. 2019 Oct 22;14(10):e0224041. doi: 10.1371/journal.pone.0224041. eCollection 2019.

Abstract

Knowledge of the geographical distribution of soils is indispensable for policy and decision makers to achieve the goal of increasing agricultural production and reduce poverty, particularly in the Global South. A study was conducted to better understand the soilscapes of the Giba catchment (900-3300 m a.s.l.; 5133 km2) in northern Ethiopia, so as to sustain soil use and management. To characterise the chemical and physical properties of the different benchmark soils and to classify them in line with the World Reference Base of Soil Resources, 141 soil profile pits and 1381 soil augerings at representative sites were analysed. The dominant soil units identified are Leptosol and bare rock (19% coverage), Vertic Cambisol (14%), Regosol and Cambisol (10%), Skeletic/Leptic Cambisol and Regosol (9%), Rendzic Leptosol (7%), Calcaric/Calcic Vertisol (6%), Chromic Luvisol (6%) and Chromic/Pellic Vertisol (5%). Together these eight soil units cover almost 75% of the catchment. Topography and parent material are the major influencing factors that explain the soil distribution. Besides these two factors, land cover that is strongly impacted by human activities, may not be overlooked. Our soil suitability study shows that currently, after thousands of years of agricultural land use, a new dynamic equilibrium has come into existence in the soilscape, in which ca. 40% of the catchment is very suitable, and 25% is moderately suitable for agricultural production. In view of such large suitable areas, the Giba catchment has a good agricultural potential if soil erosion rates can be controlled, soil fertility (particularly nitrogen) increased, available water optimally used, and henceforth crop yields increased.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture*
  • Conservation of Natural Resources*
  • Environmental Monitoring / methods*
  • Ethiopia
  • Nitrogen / analysis
  • Soil / chemistry*

Substances

  • Soil
  • Nitrogen

Grant support

This research framed in the MU-IUC programme (Mekelle University – Institutional University Cooperation) funded by VLIR-UOS (Flemish University Development Cooperation, Belgium). NM worked in the 1974-76 Tigrai Rural Development Study (TRDS) by Hunting Technical Services (UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.