Soil quality index using the CASH methodology and Rainforest Alliance Scorecard in the coffee zone of the Caldas department, Colombia

The Comprehensive Assessment of Soil Health (CASH) methodology provides a broad approach to evaluate soil health, helping farmers and researchers to identify management practices that can enhance soil health and increase agricultural sustainability in coffee crops. When integrated with regenerative agriculture strategies such as cover cropping, intercropping, agroforestry, and crop rotation, these practices can effectively enhance soil health and productivity. The aim of this research was to develop a soil health index using the CASH approach adjusted to the conditions of the coffee zone in the Caldas department (Colombia) and to adapt the index of the Rainforest Alliance Scorecard guidelines. A database containing 3,332 soil analyses from different coffee zones in the department was used, carried out between 2005 and 2021. The index obtained with historical data shows that 66% of the properties were classified as Bronze, 18% Silver, and 16% Gold, whereas the validation data showed that 49% of the properties were classified as Bronze, 21% Silver, and 30% Gold. The most important variables identified in soil health were organic matter content, organic carbon stock, CO2 equivalent, pH, bulk density, and nutrient content related to N, P, K, Ca, and Mg. CASH can be employed to evaluate the soil health status in the field using quantitative indicators linked to the Rainforest Scorecard and is a useful tool to promote regenerative practices in soil adjusted to Caldas coffee zones.