Towards SOM parameterisation in LUCIA and development of model scenarios

Parameterization and scenario development represent crucial stages in the modelling process. In particular, developing model scenarios serves as a starting point to focus attention on a specific issue, raise public and policy awareness for discussion and communication, and provide potential options for future action.

This image shows a group of farmers in discussion.

Farmer interviews and interactions for development of model scenarios at Ouarkhokh, Senegal

This image shows holes in the soil for soil sampling.

Soil sampling for C sequestration at Kamboinse long-term Piliostigma r. experiment, Burkina Faso.

Field visit to support model parameterization and scenario development

From 02 to 20th November 2023, Dr. Eric Koomson visited several field sites of our collaborators in Senegal (ISRA/ CSE), Burkina Faso (Uni Joseph KI–ZERBO, UNB, INERA), and Mali (IPR/ IFRA). The visit aimed to facilitate dialogue between different stakeholders, particularly farmers and leaders of farmer organizations through interviews towards harnessing information to guide the development of site–specific model scenarios. In Burkina Faso, a soil–sampling campaign with the support of Dr. Bazie’s group (Department of Plant Biology and Plant Physiology, Univ Joseph KI–ZERBO, Ouagadougou) was also organised at the Kamboinse experimental station to improve our understanding of the long-term contribution of Piliostigma reticulatum, a native shrub within an established agroforestry system on soil carbon sequestration at deeper rooting depths and spatial dependencies.

Stakeholder interactions

A structured interview based on cropping and livestock production systems for each study site was used to receive feedback and comments from farmers, farmer organizations and leaders of IP meetings. The questions ranged from primary challenges facing cropping and livestock systems, causes of the problem, present intervention strategies implemented, future strategies, main constraints in carrying out these interventions, how farmers are coping with drought and flood, what strategies are farmers implementing as an adaptation towards climate change, etc. In Senegal, farmers in Ouarkhokh and Niakhar participated in this exercise, whereas in Burkina Faso, farmers in Saria, and the farmer organisation CPF participated. The leader of the IP and dissemination activities in Mali took part in this exercise. Responses from these interactions are developed further, as we aim to improve model scenarios and derive land use recommendations for our stakeholders.

Soil sampling for C sequestration at Kamboinse

The main objective of this sampling campaign is to derive a soil C database at deeper depths (up to 1 m) to parameterize the LUCIA model. Soils were sampled under different planting densities (0, 500, 1000, and 2000 shrubs ha–1) of Piliostigma r. intercropped with Sorghum. Under each planting density, soils were sampled from different depths, and distances away from the shrub to account for variations in the root distribution of Piliostigma r. and its relative influence on the spatial dependencies on soil C amounts as you move away from the shrub. The samples will be analysed via conventional and Mid–Infrared Spectroscopy (MIRS) approaches. In Hohenheim, the coupled Mid–DRIFT technique will further be used to evaluate the quality of the SOC revealing the various C pools (labile, stable), which is essential for parameterizing the LUSOM file that controls the active and slow organic matter simulation in LUCIA.

Relevant links:

LUCIA; http://lucia.uni-hohenheim.de