ISRIC Report 2004/01: Soil data derived from SOTER for studies of carbon stocks and change in Kenya (version 1.0)

Year of publication
2004
Author(s)
Niels Batjes, Patrick Gicheru
Document tags
Excerpt
This report was developed in the framework of the GEF co-financed project “Assessment of Soil Organic Carbon Stocks and Change at National Scale” (GEFSOC; GFL/2740-02-4381), coordinated by The University of Reading (UK) and implemented by UNEP. The project has developed a generic sytem for estimating soil organic carbon stocks and changes at the national and regional scale. The system is driven by national or regional scale datasets of soils, climate and land use presented in standardized formats.

This harmonized set of soil property estimates has been developed using an updated 1:1M Soil and Terrain Database for Kenya. The associated soil analytical data were derived from soil survey reports. These sources seldom hold all the physical and chemical attributes ideally required by SOTER. Gaps in the measured soil profile data have been filled using a step-wise procedure that uses taxotransfer rules, based on about 9600 soil profiles held in the WISE database, complemented with expert-rules (download report).

Property estimates are presented by soil unit for fixed depth intervals of 0.2 m to 1 m depth for: organic carbon, total nitrogen, pH(H2O), CECsoil, CECclay, base saturation, effective CEC, aluminium saturation, CaCO3 content, gypsum content, exchangeable sodium percentage (ESP), electrical conductivity of saturated paste (ECe), bulk density, content of sand, silt and clay, content of coarse fragments (> 2 mm), and available water capacity (-33 to -1500 kPa). These attributes have been identified as being useful for agro-ecological zoning, land evaluation, crop growth simulation, modelling of soil carbon stocks and change, and analyses of global environmental change.