Soil Properties and Phosphorus Fractions across a Climatic Gradient in Sankuru Region, Central Democratic Republic of Congo (DRC).

Pathways to sustainable futures for small-holder farmers in DRC include increasing knowledge of highly dynamic soil properties such as organic carbon, nitrogen and phosphorus which affect the success of improved agricultural management. Nonetheless, DRC continues to be one of the least data-dense countries in the world in terms of soil information, and much of what is predicted regarding soil properties in DRC comes from only a handful of widely spaced studies and broad estimates. Understanding how soil properties vary across the landscape and change with land-use across climatic zones is a critical foundation that must be established in order to ensure the success of future efforts to improve land use practices, soil health, and food security. We report the results of exploratory work along a climatic gradient in central DRC, across the transition from equatorial forest to savanna in Sankuru and Kasai-Oriental provinces. 25 total pedons were described and sampled at 3 sites (Ekumakoko: 2.47°S, 24.03E; Katako-Kombe: 3.39°S, 24.43°E; Lubefu: 4.74°S, 24.44°E) in the study area. Within each climatic site, soil variability with regard to landscape position and land-use were considered and operational fractionation of soil phosphorus via the Hedley method was performed. Our results and analysis demonstrate the important role of climate, topography and land-use in affecting soil properties in central DRC and the resulting soil properties and classifications show that soils are more variable in this region than initially thought.