One easy way to test the soil is to get something fast-germinating, such as radish or kale seeds, and either broadcast them over the whole area, orplant them in test plots scattered around the area (well marked). You'll want to water them in and keep an eye on them to make sure they can sprout. If there are any pesticide problems, you may see deformed leaves on the plants in that area. Be sure to do a "control" flat of seeds sitting out there (same wind/sun conditions) so you have something to compare. If you do not get any germination, I'd try again.
Have you called around to UC labs to see if anyone can help test the soil? Tox screens are usually quite expensive, but you never know. It'd help to know what toxins you suspect. If it's just hydrocarbons or pesticides/herbicides, compost can often detox the soil over time. If it's heavy metals such as Pb, Cd, Zn, Hg, etc., then you may need to be more cautious. There was a good article on lead in soil in Old House Journal online some years ago -- many old houses used lead paint, so that was an important consideration. The recommendation, iirc (low to moderate levels?), was to use lots of compost, which binds heavy metals and makes them less likely to be taken up by plant roots. For plants grown directly in that soil, they rec'd avoiding root vegs and leafy greens, but any fruiting plant was ok: tomatoes, cukes, squash, etc. The main hazard was from soil tracked into the house, or if kids played in the soil (from both ingestion of soil and breathing the dust), not from plant uptake. Yet another option is to grow in something like milk crates lined with landscape cloth. The milk crates with soil and plants sit on another layer of milk crates, so your pristine soil is totally separate. There have been large installations of these kinds of "portable" modular gardens in NY City (on a roof next to a restaurant) and in Germany. On Wed, Apr 3, 2013 at 10:51 AM, Diann Dirks <[email protected]> wrote: > My suggestion would be to make bio-char (see the videos on how to make it > at Prokashi.com) and after infusing the activated charcoal with bio infused > micro organism material such as described, and fermented for about 2 weeks > (don't leave out this step), use that as a layer under the raised beds - > probably about an inch deep, and on top of that use several layers of > cardboard, then set your good soil in boxes over it. The bio-char > remediates toxins and the microorganisms infused into the charcoal and then > fermented processes them. You could do a trial on this for about a year > then test the garden soil in the box for toxins, and dig up some below. I > think this would work well. Worms will work the bio-char into the soil as > deep as the roots would go. > Diann Dirks > Certified Permaculture Designer > Auburn CG, Ga. > ----- Original Message ----- From: "Guy Serbin" <[email protected]> > To: "Robin Mitchell" <[email protected]> > Cc: > <community_garden@list.**communitygarden.org<[email protected]> > > > Sent: Wednesday, April 03, 2013 1:04 PM > Subject: Re: [Community_garden] Geotextile cloth for lining raised beds > > > > Hi Robin, >> >> I can't answer specifically on the geotextile issue. However: >> 1. Yes, the best option would be to use shallow rooting soils and make >> sure >> they are adequately irrigated- contaminants can move upward in soils due >> to >> osmotic/ capillary forces and evaporation. >> 2. If you have an idea as to what the contamination might be, have >> multiple >> soil samples from varying depths tested for said contaminants. Certain >> tests, e.g., lead, can easily be done by commercial or university soil >> labs. >> >> You may also want to do a search to see if anyone is conducting a study >> into community/ urban garden soil quality and contamination. I would not >> be surprised if multiple studies are being done. >> >> Best regards, >> Guy Serbin >> >> >> On Wed, Mar 27, 2013 at 5:59 PM, Robin Mitchell < >> [email protected] >> >>> wrote: >>> >> >> A;l -- >>> >>> We are in the process of installing some raised beds for a community >>> garden >>> project on a site which "potentially" has soil toxicity problems, >>> although >>> we are not sure, and we don't have the funds to test. >>> >>> So just to be on the safe side, we are doing raised beds and putting in >>> high quality soil for growing vegetables. >>> >>> It has come up that we should / could line the beds with a "geotextile" >>> cloth that will prevent the vegetable roots from getting into the native >>> soil. >>> >>> I looked at a geotextile cloth carried by a local erosion control >>> company, >>> but it was embedded with some sort of petroleum based product, which >>> seemed >>> completely counter to having a nice organic vegetable garden. And in >>> general it seems like these "cloths" are made from pretty nasty materials >>> that will eventually end up either in the soil or in a landfill >>> somewhere. >>> >>> So I am thinking we don't want to use them, but thought I would see if >>> any >>> other community gardens had any experience with them before dismissing >>> the >>> idea. >>> >>> Now I am thinking that we will make sure to plant only plants with >>> relatively shallow roots (this was a recommendation I read somewhere) >>> that >>> will not go deeper than about 1.5 feet (our beds are 2 feet deep). Any >>> comments about that as a strategy ? >>> >>> Thanks for your input ! >>> >>> Robin >>> -- >>> Robin Mitchell >>> El Cerrito Community Garden Network >>> Email: [email protected] >>> Web: >>> https://www.sites.google.com/**site/elcerritocommunitygarden/<https://www.sites.google.com/site/elcerritocommunitygarden/> >>> -------------- next part -------------- >>> An HTML attachment was scrubbed... >>> URL: < >>> http://list.communitygarden.**org/pipermail/community_** >>> garden_list.communitygarden.**org/attachments/20130327/** >>> d912ed1a/attachment.html<http://list.communitygarden.org/pipermail/community_garden_list.communitygarden.org/attachments/20130327/d912ed1a/attachment.html> >>> > >>> ______________________________**_________________ >>> The American Community Gardening Association listserve is only one of >>> ACGA's services to community gardeners. To learn more about the ACGA and >>> to >>> find out how to join, please go to http://www.communitygarden.org >>> >>> To post an e-mail to the list: community_garden@list.** >>> communitygarden.org <[email protected]> >>> >>> To subscribe, unsubscribe or change your subscription: >>> http://list.communitygarden.**org/mailman/listinfo/** >>> community_garden_list.**communitygarden.org<http://list.communitygarden.org/mailman/listinfo/community_garden_list.communitygarden.org> >>> >>> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://list.communitygarden.**org/pipermail/community_** >> garden_list.communitygarden.**org/attachments/20130403/** >> 89d0b81f/attachment.html<http://list.communitygarden.org/pipermail/community_garden_list.communitygarden.org/attachments/20130403/89d0b81f/attachment.html> >> > >> ______________________________**_________________ >> The American Community Gardening Association listserve is only one of >> ACGA's services to community gardeners. To learn more about the ACGA and to >> find out how to join, please go to http://www.communitygarden.org >> >> To post an e-mail to the list: community_garden@list.** >> communitygarden.org <[email protected]> >> >> To subscribe, unsubscribe or change your subscription: >> http://list.communitygarden.**org/mailman/listinfo/** >> community_garden_list.**communitygarden.org<http://list.communitygarden.org/mailman/listinfo/community_garden_list.communitygarden.org> >> >> > > ______________________________**_________________ > The American Community Gardening Association listserve is only one of > ACGA's services to community gardeners. To learn more about the ACGA and to > find out how to join, please go to http://www.communitygarden.org > > To post an e-mail to the list: community_garden@list.** > communitygarden.org <[email protected]> > > To subscribe, unsubscribe or change your subscription: > http://list.communitygarden.**org/mailman/listinfo/** > community_garden_list.**communitygarden.org<http://list.communitygarden.org/mailman/listinfo/community_garden_list.communitygarden.org> > -- If you have a garden and a library, you have everything you need. -- Cicero -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://list.communitygarden.org/pipermail/community_garden_list.communitygarden.org/attachments/20130403/f431c324/attachment.html> _______________________________________________ The American Community Gardening Association listserve is only one of ACGA's services to community gardeners. To learn more about the ACGA and to find out how to join, please go to http://www.communitygarden.org To post an e-mail to the list: [email protected] To subscribe, unsubscribe or change your subscription: http://list.communitygarden.org/mailman/listinfo/community_garden_list.communitygarden.org
