Thomas Fungenzi is a PhD student with the University of Cranfield and is currently looking for datasets to enhance his research on modelling soil fertility restoration strategies using organic inputs in cocoa plantations. Any interactions to promote this project with the CocoaSoils network will be welcomed. Below is an excerpt of his presentation on his thesis topic. Follow this link to see the entire presentation. Soil organic matter (SOM) reflects key aspects of soil functioning and is sensitive to management. It has direct and indirect influences on plants. SOM is, for example, a reservoir of nutrients, often linked to water holding capacity, buffers pH, contributes to CEC, stimulates growth and acts as a reservoir of matter and energy for soil micro-organisms. The aspiration of this study is to support decision-making around cocoa soil fertility management. The purpose of this research project is to evaluate the capacity of organic inputs to improve cocoa production by restoring optimal SOM levels. The characterisation of SOM dynamics is addressed by a literature review, a meta-analysis, field measurements and a modelling exercise. Soil samples were collected in a chronosequence of Indonesian cocoa farms (ranging from 0.5 to 31 years old) and results will be used in the models. Different organic input strategies (i.e., “restoration scenarios”) will be assessed through simulations. Variations will involve nature and quality of the organic inputs, timings and application rates to reach a range of soil organic matter targets. The final stage will be to estimate the effect on production. The possible effects of SOM on soil fertility properties will be investigated using pedotransfer functions. The influence of organic inputs on soil water holding capacity will be the prime focus since soil water is a key driver of cocoa production. The impacts on cocoa growth, and potentially on yields will be investigated further, using other models such as WalNulCas and CASE2.

Contribution by: Thomas Fungenzi