I'm about to take up a new allotment with a friend, but it's very near the M25 (No. I mean
really near. look
here. It's the one in the middle.)
Obviously lead levels are going to be pretty high, but I've carried out soil samples in the area and the levels aren't prohibitive. However, we still reckon it can be improved on and being biologically minded it occurs to us that there must, somehere, be a plant that preferentially removes lead from the soil. Because it's a natural toxin a lot of plants have natural barriers to it, leading to things like potatos and carrots with very high lead levels in their skin.
Because it's late in the season, we were wondering whether it's worth trying to get a late crop of something in that might draw out some of the lead that we can then harvest and remove from the site.
Has anyone tried anything similar, or know of any lead reducing tactics other than simply bulking up the soil with plenty of earth and compost from elsewhere?