Earthworms Missing in Volcanic Madeira Soil: pH, Eucalyptus, and Microbial Life

Gardener in northern Madeira (1500 ft) has acidic volcanic soil, added calcified seaweed, K, P, mulches with acacia. Few earthworms. Possible causes: low pH (even after amendment, takes time), eucalyptus oils (antimicrobial, may deter worms), acacia seed litter, lack of microbial diversity. Suggestions: retest pH in 6–12 months, add forest byproducts/manure for nitrogen, consider cover crops, introduce worm species suited to acid soils. Connect with local permaculture network (Pat Tyler in Calheta).