Skip to Content.
Sympa Menu

homestead - Re: [Homestead] [Fwd: Re: bev - Potato Q - and Sage]

homestead AT lists.ibiblio.org

Subject: Homestead mailing list

List archive

Chronological Thread  
  • From: EarthNSky <erthnsky AT bellsouth.net>
  • To: homestead AT lists.ibiblio.org
  • Subject: Re: [Homestead] [Fwd: Re: bev - Potato Q - and Sage]
  • Date: Tue, 09 Dec 2008 13:59:56 -0500


Lisa K.V. Perry wrote:


I've heard of this method but always wondered what the effects or consequences were, if any, of having soil and plants surrounded by rubber. Nothing leaches out of the tire?

Lisa


Well, if you want to be scared silly, you can read this, which is about
the products that leach/outgass from recycled tire products used in
making turf products...
http://www.ehhi.org/reports/turf/health_effects.shtml
This page lists some of the testing descriptions that support the first
page:
http://74.125.45.132/search?q=cache:wE-ztzVd6OkJ:www.ct.gov/caes/lib/caes/documents/publications/fact_sheets/examinationofcrumbrubberac005.pdf+tires+rubber+outgassing&hl=en&ct=clnk&cd=4&gl=us


I've never personally tested the soil inside of a tire while it was in
use, or a potato growing in said tire but I am not worried about it, and
here's why..
First, the tires are steel/metal belts encased in a thin layer of
vulcanized rubber. Rubber, as you know, is a natural product, but it
has to be treated, vulcanized, in order to be used as a tire.
Wiki has a decent article on vulcanization.
http://en.wikipedia.org/wiki/Vulcanization
It is the various cross-linking agents and additives that are used in
the process that leach back out...things like zinc from zinc oxides..


In the above studies, tires were shredded into crumbs...Mine remain
whole for the most part. Some people who are worried about the sun
heating the tire and increasing outgassing/leaching effects will paint
the tires as a sealant, but I don't worry about it.
1. Outgassing....this is seemingly everyone's biggest fear. If a tire
outgasses in the garden, and no one is there to breath it..lol..just
kidding..sort of...Volatile organics are gases, and gases won't go into
liquids or solids at normal pressures...It would take some kind of
pressure to push benzothiazole into a potato. Now, if I were to make a
mat of recycled tire products, like they do on playgrounds, I don't
know that I would allow my granddaughter to crawl around on it
24/7(maybe for 5 minutes once a month is okay though-I don't know), but
I would allow her to eat a potato grown in a tire.
2. Leaching....more serious, IMO...the problem elements here are zinc,
cadmium, lead, and selenium..With normal water, you get some leaching of
these elements, but that is increased if the water/rain is acidified(or
if the soil is acid and acidifies the rain) The links I provided test
the tire crumbs, not the intact tire. But even with those higher
concentrations, (see the bottom of the second link), it is not really
enough to warrant concern as a health issue, even if you drank the leach
water directly. People don't like to think about it, but store-bought
food, especially potatoes, contain a lot more bad stuff than anything I
grow in tires. Taking their findings, for example, that there is 0.26
ppb Cadmium(parts per BILLION), and knowing that the FDA says that up to
15 parts per MILLION is okay, that helps put things in perspective, or
at least it does for me. If there is .26 ppb of cadmium in the
leachwater/rainwater, how much of that goes back into the ground and how
much is absorbed into or by my potato plant?...even less...

The way I look at it is this...I am using old tires, not new rubber.
The rubber on the tires I use has hardened and over the years has
already outgassed some in whatever dump, backlot, or junkyard it was in
before I got it. I am not opening up the the tire to expose the metal or
cutting it into shreds..I am using a whole tire with one sidewall
removed, which, if anything would allow more gas to escape into the
atmosphere instead of being held within the housing of the tire, i.e.
next to the potato plant...It takes a few months to grow a stack of
potatoes, and only the bottom tire is there for the whole duration of
that time...In the life of the potato vine/surrounding tire, it may only
rain once or twice..As to the leaching of the metals contaminating my
garden soil...fear not. I have had my garden soil tested(at great
expense) and I am non-detect for metals like this...
As to the leaching of the metals contaminating my garden soil...fear
not. I have had my garden soil tested(at great expense) and I am
non-detect for metals like this...


You know, there were stories in the news a while back about farmers who
grew potatoes for McDonald's french fries...The soil was so contaminated
that not only would the farmers not eat the potatoes they grew, or
obviously the fries, but they would not grow other crops on the same
land...that says something to me, that the way agribusiness grows
potatoes is very, very bad. Surely, the way I do it is not as harmful...

So, I don't worry..but, all of the above is my two cents..

Bev





--
“Fear is the path to the Dark Side. Fear leads to anger. Anger leads to
hate. Hate leads to suffering.” Yoda




Archive powered by MHonArc 2.6.24.

Top of Page