According to results I got today from the soil testing lab at Umass Amherst.
Not, interestingly, the shady back part of the yard, so food plants which can handle shade well will go there.
I've been investigating pytoremediation methods for pulling the lead out so that we can eventually plant food plants in the rest of the yard. So far, it seems that plants store the least heavy metals in their fruiting parts, most in their leaves, and inconsistent ammounts in their roots. So leafy things are the best possibility. Specifically, it seems that Indian Mustard and regular sunflowers do a decent job at it, although most studies also use something which makes heavy metals bind to the soil less and be more available for plant uptake more (chelating agents). The problem here is that the chemicals in question too easily allow the lead to get into the water table. So, definitely not using that part of what people have done in their minimal studies so far.
So, in the immediate term, for places that are not the lawn, I will be trying to plant - and later remove and put in the trash - sunflowers and, once I get some seeds, Indian Mustard in non-lawn parts of the garden.
Another possibility, since I would really like to not have many plants in pots for watering requirement reasons, is hugelkultur. Or, I suppose, a more typical raised bed. But it seems like it would be a waste of the lovely brush and also more work later.
We have a bunch of brush from around the yard last year, and it would be lovely to be able to use it in a useful way. It seems helpful to stick those in the ground, along with other lovely things to decompose, and let them capture water for us and make whatever we grow easier and healthier. It does, however, mean that we'd need to get rid of the top layer of dirt and replace it with some sort of non-lead topsoil. I do, of course, still need to verify that this is not going to be problematic for
galaneia or metahacker.
So, yard. Darn heavy metal...
Not, interestingly, the shady back part of the yard, so food plants which can handle shade well will go there.
I've been investigating pytoremediation methods for pulling the lead out so that we can eventually plant food plants in the rest of the yard. So far, it seems that plants store the least heavy metals in their fruiting parts, most in their leaves, and inconsistent ammounts in their roots. So leafy things are the best possibility. Specifically, it seems that Indian Mustard and regular sunflowers do a decent job at it, although most studies also use something which makes heavy metals bind to the soil less and be more available for plant uptake more (chelating agents). The problem here is that the chemicals in question too easily allow the lead to get into the water table. So, definitely not using that part of what people have done in their minimal studies so far.
So, in the immediate term, for places that are not the lawn, I will be trying to plant - and later remove and put in the trash - sunflowers and, once I get some seeds, Indian Mustard in non-lawn parts of the garden.
Another possibility, since I would really like to not have many plants in pots for watering requirement reasons, is hugelkultur. Or, I suppose, a more typical raised bed. But it seems like it would be a waste of the lovely brush and also more work later.
We have a bunch of brush from around the yard last year, and it would be lovely to be able to use it in a useful way. It seems helpful to stick those in the ground, along with other lovely things to decompose, and let them capture water for us and make whatever we grow easier and healthier. It does, however, mean that we'd need to get rid of the top layer of dirt and replace it with some sort of non-lead topsoil. I do, of course, still need to verify that this is not going to be problematic for
galaneia or metahacker.So, yard. Darn heavy metal...
Comments
http://news.nationalgeographic.com/n
I end up having to pull wysteria every so often. Ah, well. Otherwise, though, seems delightful! It does also appear to allow critters which eat carrots to get in and eat the bottoms. But as long as it's not all of them, whatever. Y'know?
It may be that the shady part that came back with low levels has simply been disturbed or been brought from elsewhere at some point, so the sample you took didn't catch the layer of soil that's highest in lead. We had a few samples come back low, one was above a spot that had been a trash dump at some point. *shrug*
So either you bring in a lot of topsoil from a distant rural area, you try to do phytoremediation and be super-patient knowing it's not a total cure either, or you test, verify that there is no high-level contamination such as from lead paint in your soil, and accept that there's a background level that a majority of the backyard gardeners in the developed world are all stuck with, thanks to the Ethyl corp. Then consider the health benefits from the goodness of eating your own super-fresh produce, and proceed with caution.
We did raised beds of course, and the organic matter we've added combined with the double-digging and dirt we've brought in has probably lowered the (background level for where we live) lead count in the soil. I think we're overdue to retest it at this point, but I'm curious.
re: brush. Yes, you could shred and chip the brush and bury that in the ground. We just did that with our accumulated brush and put it at the bottom of our first raised bed as it was rebuilt. I bought a chipper/shredder for the task, in fact. It was satisfying but tedious work. If you bury the brush without breaking it up first, it's going to be harder to dig there again later.
And noted re lead. Lots of info I was unclear on. Now I kind of want to know where the dust dome is likely to have been. I know we're further from Boston than you guys are, for example!
(also, medium = 300-999. Specifically, 858, 398, 470, 424, 471, 515, 397. Low is 284. All ppm)
The idea of a dust dome is kind of a vague thing, since prevailing weather patterns and topography affect how exhaust gases drift. But wherever there's a population cluster, there's more exhaust, and it's densest at the center, usually. Probably being outside 128 is one way to look at it, but it's not suddenly worse as you cross in from there...
Ah, those are higher numbers in the moderate range, yes. Higher than we had here, though I'm struggling to recall what the normal background level I heard was for Somerville.
But I do like my raised bed gardens! In fact, I'm thinking about putting in a 3rd bed. I'm not sure yet what I'd plant other than tomatoes and some herbs this year - do you want to do some veg gardening over here?