Journal Article

Determinants of Field‐Saturated Soil Hydraulic Conductivity Across Sub‐Saharan Africa: Texture and Beyond

Bargués‐Tobella, Aida, Winowiecki, Leigh Ann, Vågen, Tor‐Gunnar, Sheil, Douglas

2024

Overview

Soil infiltration is critical for water security and related ecosystem services. This infiltration, the ability of soils to absorb water at their surface, is controlled by the soil hydraulic conductivity. Despite recent efforts in assembling measurements of soil hydraulic conductivity, global databases and derived pedotransfer functions lack coverage in the tropics. Here, we present soil infiltration measurements and other indicators of soil and land health collected systematically in 3,573 plots from 83 100 km 2 sites across 19 countries in sub‐Saharan Africa. We use these data to (a) determine field‐saturated hydraulic conductivity ( K fs ) and (b) explore which variables best predict variation in K fs . Our results show that sand content, soil organic carbon (SOC), and woody cover had a positive relationship with K fs , whereas grazing intensity and soil pH had a negative relationship. Our findings highlight that, despite soil texture being important, structure also plays a critical role. These results indicate considerable potential to improve soil hydrological functioning through management and restoration practices that target soil structure. Enhancing SOC content, limiting animal stocking, promoting trees, shrubs, and other vegetation cover, and preventing soil erosion can increase K fs and improve water security. This data set can contribute to improving Earth system and land surface models for applications in Africa. We present field infiltration measurements and accompanying indicators of soil and land health from 3,573 plots across sub‐Saharan Africa Field‐saturated hydraulic conductivity ( K fs ) is associated with soil texture and factors related to soil structure Our results suggest that soil hydrological functioning can be enhanced through management practices that target soil structure

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Agriculture / Ecosystem services / Food security / Grazing intensity / Groundwater / Groundwater recharge / Hydraulic conductivity / Hydraulics / Hydrology / Infiltration / Land surface models / Land use planning / Organic carbon / Plant cover / Restoration / restoration and management practices / Saturated soils / Security / Soil chemistry / Soil conductivity / Soil erosion / soil hydraulic conductivity / soil hydrological functioning / Soil improvement / Soil infiltration / Soil pH / Soil properties / Soil structure / Soil texture / soil texture and structure / Soil water / sub‐Saharan Africa / Texture / Tropical environments / Vegetation / Vegetation cover / Water security / Water shortages