Cocoa suitability mapping using multi-criteria decision making: An agile step towards soil security

• Published in: Soil security 2021-12, Vol.5, p.100019, Article 100019
• Main Authors: Singh, Kanika, Fuentes, Ignacio, Fidelis, Chris, Yinil, David, Sanderson, Todd, Snoeck, Didier, Minasny, Budiman, Field, Damien J
• Format: Article
• Language: English
• Subjects: Agricultural sciences; Analytic hierarchy process; Cocoa suitability; Life Sciences; Multi-criteria decision making
• ISSN: 2667-0062; 2667-0062
• DOI: 10.1016/j.soisec.2021.100019

Cocoa production is impacted by major resource constraints, such as the soil's capability, and in some areas, by unreliable access to markets. A multifaceted approach that employs both biophysical and socio-economic conditions is developed here for mapping areas that are suitable for cocoa production in Papua New Guinea (PNG). This manuscript presents a case study of using multi-criteria decision making by the Analytic Hierarchy Process for mapping the fundamental criteria for cocoa suitability. The results show that temperature, precipitation and soil reveal sections within Western, Gulf and Central (along the west coast joining to National Capital District) province that have very low suitability for cocoa production. In our analysis, precipitation, soil, slope and road, were ranked as the four most important criteria. Additionally, we included stream networks because they may help irrigation and allow cocoa transport via water (e.g. Manus Island). Comparing an already existing cocoa suitability map for PNG to the one created in this study, we found some similarities. For example, the Central, Gulf, and Western (Fly) areas are either unsuitable for cocoa production or have very low potential, and exceptional areas around Rabaul and Kokopo in East New Britain, Popendetta, and Bouganiville were identified. Some new areas suitable for cocoa production in East Sepik, East New Britain, and a major stretch within West New Britain may show low to moderate suitability. The most important finding is the potential to grow cocoa in the highlands, especially, Chimbu (Simbu), Eastern Highlands, Enga, Hela, Jiwaka regions. We found that currently the majority of farmers are growing cocoa in highly suitable areas (76% in class 4, 20%in class 3 and 4% in class 5). The inclusion of slope and roads impacts the impact of flooding conditions and the amount of work and ease of access to markets as important indicators of the connection farmers make between soil suitability and their decision to grow cocoa. This is an agile step towards linking biomass production to soil capability, and connectivity, allowing cocoa suitable areas selection and the production of ‘living maps’ that continually evolve as more empirical data becomes available. This can be an essential connectivity tool for practitioners to evaluate the potential geographic range for cocoa production.