Lead Remediation Study
It is well known that soil fungi can sequester heavy metals along their hyphae and thereby keep them from entering into the tissue of plants. Living Soil Network is has successfully diminished the lead content in two previous test sites in the Portland area. However those studies were not well documented.
This project will document the use of soil biology in combination with pollinator plants that have strong mycorrhizal affinity, as a method for removing lead from garden soil. The study plot’s current lead figure is 680 ppm.
A variety of ornamental perennial pollinator garden shrubs will be planted in a 4’ by 20’ garden plot in the Living Soil Network’s demonstration property in South Portland, Maine. Additions of microbially rich compost will be added at each planting. Microbial extracts will be applied every 3 weeks during the growing season. The soil will be monitored for microbial activity once a month during the warm seasons. The soil will be tested for lead in early May of 2024 and again in the fall of 2024. In the spring of 2025, the lead content will be tested again. If the soil lead levels test below 150 ppm at that time, the perennial plants will be removed.