Assertion: worm's casting | /r/MadeOf | humic acid
Facets:
Source sentences:
text: Castings contain humic acid which can control plant pathogens while stimulating healthy plant growth and they have a neutral pH. A mixture of organic matter and minerals, castings are also rich in nitrogen, phosphorus, potassium, calcium, iron, magnesium, and sulfur in a soluble form that plants can readily use.
text: In addition, castings contain humic acid which aids plant nutrient absorption.