Soil quality index for cacao cropping systems

ABSTRACT

The soil quality index (SQI) for cacao cropping systems was developed to meet the nutritional criteria of the crop, the environmental safety of the cropping sites and the increasing demand for the production and quality of cocoa. Available water function (AWF), root growth function (RGF), mineral nutrition of plants function (MNF) and environmental safety function (ESF) for potentially toxic elements were included in the additive model of SQI for cacao cropping systems. In this study, over 66% of the cacao fields cropping sites were classified as regular SQI with a range of scores between 0.42 and 0.61. The field cropping site with the highest score (0.73) characterized as typic Alitic Red-Yellow Argisol was rated with high SQI. In contrast, the field cropping sites characterized as abrupt Cohesive Dystrophic Red-Yellow Argisol (0.29), typic Dystrophic Haplic Cambisol (0.39), and latosolic Dystrophic Yellow Argisol (0.40) were rated with low SQI. MNF and AWF were the functions that most contributed to the increase or decrease of SQI scores. The SQI adapted expressed the agro-environmental reality of cacao cropping systems of Bahia, Brazil, and this could be a versatile tool to subsidize the adequate soil management of cacao plantations around the world.

KEYWORDS:

• Soil quality
• Theobroma cacao L.
• plant nutrition
• soil management
• cropping systems
• agricultural sustainability

Acknowledgments

This paper is part of the project ‘Linking soil quality and cacao quality in Bahia, Brazil’. To run fundamental steps of this research, the corresponding author was supported by the Brazilian National Council for Scientific and Technological Development (CNPq) with a Postdoctoral fellowship. The project SCA 58-1245-3-237F of USDA-ARS-FUNPAB partially supported the field and lab activities. We thank Marshall Elson for peer review of this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.