Integrated Digital Soil Assessment across South East Asia and Africa.

Digital Soil Assessment (DSA) methods are increasingly being applied as integrative step in which DSM outputs are incorporated into crop and land management decision support systems, often through the vehicle of process models. The value of the acquisition, interpretation of any soil data, and the additional effort in developing and producing a DSM product resides in its use and utility. The purpose of DSA is the development of the value argument for the conversion of quantitative data on soil properties obtained through DSM to a spatial assessment of the capacity of a soil to fulfil a particular function. Here we present the use of DSM/DSA to i) demonstrate the discovery new soil process knowledge on rice production in Bangladesh and the conditions which can determine heavy metal accumulation; ii) determine and illustrate DSA under data sparce conditions through mapping areas in West Africa under which Fe toxicity in the soil limits agricultural production and iii) integration of DSA in a wider decision support system to support decision making in a semi-arid region in Morocco, illustrating the trade-offs between agricultural production and ecosystem services. Through these case examples, we demonstrate the flexibility of DSA approaches in addressing both the generation of new knowledge around soil processes, in justifying the acquisition of new soil data and in helping landowners to manage their crops and soils sustainably.