Farmers’ perceptions of earthworms and their role in soil

• We evaluated 39 farmers’ perceptions of earthworms in the Colombian coffee belt.
• Age, gender, and level of schooling affect farmers’ perceptions of earthworms.
• 95% of the farmers perceived earthworms as good indicators of soil quality.
• Farmers recognized 9 species according to morphological characters, uses and locality.
• Local knowledge on earthworms is important for biodiversity conservation.

Farmers’ perceptions of earthworms were surveyed based on the criteria they use to identify them, i.e., use of common names, knowledge of morphological characteristics, presence in various land uses, soil layers, as well as direct and indirect use. A total of 39 farmers of the La Vieja River watershed in Colombia were interviewed and the data submitted to chi-square test and multiple correspondence analysis. Significant differences (p < 0.1) were found in farmers’ replies in relation to recognition and use of earthworms depending on gender, level of schooling, and age. According to the interviewees, earthworm abundance was highest in plantain and coffee crops, in places where harvest residues accumulate, and in soil layers from 0 to 20 cm depth. The topsoil was identified as the main area of recognition, which can be attributed to soil preparation tasks. Farmers differentiated earthworms by shape and color and in 97% of the cases, by size and how they react when captured. They recognized nine species and used several common names to differentiate them. Most (95%) farmers considered earthworms as soil quality indicators and many (38–49%) of them recognized their use for recreation and medicinal purposes and as important for soil organic matter decomposition. This study showed the value of local farmer knowledge for scientists as part of research aiming to facilitate communication between farmers and scientists and generate complementary means of addressing and interpreting natural processes and dynamics at the ecosystem level. It also highlights the need to draw from farmers’ perceptions in informal education processes and to link the contributions of scientists to traditional knowledge in order to consolidate proposals related to biodiversity conservation and use in rural development programs.