Living Wind wrote:Never ever ever ever had a problem with card stock/board as base layer... I've done a couple hundred sheet mulched beds now. Never an issue. But sure, use common sense..Rip tape/adhesive off.
Nick Garbarino wrote: A healthy microheard can remediate just about anything, other than heavy metals, so unless cardboard and newspaper are loaded with too much heavy metal, I just don't see any issue. In my humble opinion.
paul wheaton wrote:This would be a good time to point out that one could create cardboard using 100% mechanical means, plus using organic corn starch for the glue. So, I suppose there could be something called "organic cardboard". Further, as Paul Stamets points out, the seeds of edible plants could be worked into the cardboard. So when you get a package, you can bust open the cardboard and then toss it out on your lawn. A few months/years later you can have all sorts of fun stuff growing there!
Now I understand why Paul Wheaton hates using cardboard on the garden. It is often laced with fermaldehyde if it comes from China ( usually more flimsy or says made in China) this pile was pulled out of my sister's garden after three years used for mulching under straw and wood chips. Not one wormhole nor any fungi at all grew on it. She too hates cardboard in the garden. I was awestruck by the total in-biodegrability of it
Chinese formaldehyde-laced cardboard. three years in the garden, no signs of wear.
Nick Kitchener wrote:The risk of formaldehyde contamination from cardboard in sheet mulching has been well and truly discussed. What I have not seen anywhere is a discussion about using this same cardboard as a growing medium for mushrooms.
We know that mycelium are very good at absorbing toxins, and corrugated cardboard is a widely used growing medium for cultivating oyster mushrooms and other culinary strains.
Formaldehyde is not expected to adsorb to soil particles to a great degree and would be considered mobile in the soil, based on its estimated Koc. According to Kenaga (1980), compounds with a Koc of <100 are considered to be moderately mobile. Formaldehyde can be transported to surface water through runoff and to groundwater as a result of leaching. Parameters other than Koc affecting its leaching to groundwater include the soil type, the amount and frequency of rainfall, the depth of the groundwater and the extent of degradatio n o f formaldehyde. Formaldehyde is susceptible to degradation by various soil microorganisms (U.S. EPA, 1985). Howard et al. (1991) estimated a soil half-life of 24-168 hours, based on estimated aqueous aerobic biodegradation half-lives.
the chemical 4-methylbenzophenone, this component of printing ink had slipped from the outside of the cardboard box and into the cereal. That is, until the European Food Safety Authority (EFSA) was asked to look into the matter.
Study of cardboard colorants and heavy metals