Feedback on Plastic Mulch

How can Tom Doyle ("More Plastic Mulch!" in MOTHER NO. 11) improve the fertility and humus content of his sail year after year if he leaves his plastic mulch in place for a 10 to 20 year period? Seems to me that he's taking away from the soil without putting anything back . . . that's not natural gardening, that's robbery!

Give me good ole rotten hay and the leaves from a nearby town any day.

Sally Goldblatt
Honeoye Falls, N. Y.

As a gardener, I have some serious reservations about black plastic mulch, especially a permanent one (TMEN NO. 11). F. P. Hughes talked about attempting to sterilize some ground with plastic in order to make a nice lawn, and I'm afraid it might be possible. Only I doubt that the mulch would select out dandelions and plantain (eat them, no?). It's possible you just might wipe out whole subterranean micro-populations. Soil health depends heavily on all the tiny beasties that live in it, and we don't know that those near the surface are not harmed by being constantly in total darkness with reduced air circulation. Light is essential to many life processes; we can't just assume that it's unimportant to soil life (there's a really good article on light as "nutrient" in the July, 1971 issue of PREVENTION magazine . . . worth digging up if only for the questions it raises).

Plastic doesn't feed the soil, either, and it makes it hard for the gardener to do so. Taking without returning equals depletion (theft, rip-off) I would think, even if the first years bring fantastic crops. The fact that this black plastic "works" should by itself be no selling paint to gardeners concerned about the long-term health of the soil. Hard pesticides "work." So do chemical fertilizers.

I haven't used plastic sheeting in my own garden (I may, in a little corner . . . but I'm certainly not ready to turn my lone acre over to it). I'm skeptical about the material lasting 10 or 20 years in usable size. We put clear six mil plastic on the side of a drafty house once, and it was shredded to smitherines the second year. Wind got into pin holes and worked on it until the plastic was finished . . . and it ain't cute hanging in the trees. More protected if flat on the ground, granted, but 10 years . . . ? Seems that one sharp-toed pooch on a spree could do enough damage to make a strip of the stuff useless.