“It used to be,” writes William Bryant Logan in Dirt, “that a good farmer could tell a lot about his soil by rolling a lump of it around in his mouth.” Today, apparently, it is harder to find someone who literally eats dirt:
Not in Texas, nor Vermont, nor Kentucky, nor California, nor western New York. Everybody knew somebody who once did it, but nobody could quite remember the name of the fellow.
Finally, Logan came across Bill Wolf, an organic pioneer who started his environmental research under Buckminster Fuller and who used to eat soil, until his doctor forbade him.
Soil contains bad bugs as well as good ones, and the physician did not want to have to sort them out in Wolf’s guts. But back in the days when he chawed, Bill could tell acid from alkaline by the fizz of the soil in his mouth.
A very acid soil would crackle like those sour candies that kids eat, and it had the sharp taste of a citrus drink. A neutral soil didn’t fizz and it had the odour and flavour of the soil’s humus, caused by little creatures called “actinomycetes.” An alkaline soil tasted chalky and coated the tongue.
Having conducted this simple taste test, Logan explains, farmers could apply calcium carbonate to the Sprite-flavoured fizzy soil and gypsum to the Milk of Magnesia tongue-coating soil, which would then “react with the hydrogen of acid clays and the sodium of salt-clays, respectively,” in order to re-balance the soil’s pH and improve its structure.