Q. I have one concern about the Mittleider Method. Since you use mineral nutrients from commercial sources, do those – or could they – cause a toxic build-up in the soil, and might they leach into the groundwater, eventually adding to the problems we have in our streams, rivers, and oceans? Hopefully you have a good answer, because I love everything else I am seeing with this method of growing!
A. We do indeed have an answer. In 1998 Dr. Mittleider and I hired two highly respected soil labs to perform extensive tests for us regarding this very question. The two labs were Stukenholtz Labs, in Twin Falls, Idaho, and the Brighham Young University Soil Testing Lab, in Provo, Utah.
I don’t remember the number of test holes drilled, but I think it was 45. Three gardens were tested for build-up of fertilizer salts. Test cores were used at 1′, 2′, and 3′ depths in each hole.
One garden was Dr. Mittleider’s own backyard garden, which had been used for 21 years at that time; the second location was my garden at Utah’s Hogle Zoo, which had been used for 9 years; and the third garden was a very visible large garden 20 miles South of Salt Lake City at a place called Thanksgiving Point, which had been in use for 4 years.
There was NO toxic build-up of salts in ANY of the test sites. There was NO indication of ANY fertilizer being flushed into waste-water systems. And some of the test holes even had LOWER salt levels than the controls, which were taken from non-fertilized aisles and garden periphery.
This did not surprise us (although it surely did surprise a few folks who had been accusing us of polluting the ground water), because we use very little mineral salts, and we spread their application over the growing season.
We only apply 7+ ounces of fertilizer salts to about 3,300# of soil, and do it every 7 days, but for most crops we only apply it about 5 times. Everbearing crops might get8 to 12 applications, spread over several months.
Compare this to the many POUNDS of fertilizer salts organic growers apply to their gardens ALL AT ONCE before planting. That concentrated one-time application is much more likely to cause run-off or seepage into the groundwater than the small amounts the Mittleider gardener applies.
Our vegetables are healthier, because they receive their nutrition throughout the season, as they need it. And being very healthy, they have high brix values, and are less susceptible to diseases and pests, as well.