Walk outside, and the air is wet. Touch the ground, and the dirt is dry. This is the inverse of what a farmer wants. Fieldhands simmer in dense atmospheric steam as they set out irrigation for parched fields of thirsty crops. Every farmer I have spoken to has had one world for this summer’s conditions: dusty.
But what is in this dust, and why has it become so dusty? The simple answer would be: a) it is dry dirt and b) it got dry because we are in a drought. But I thought I could do better, and that by digging into a), I might shed some light on b). And I always jump at the opportunity to indulge in excessive and esoteric agronomic research.
So, I dove headfirst into Dukes County soil surveys. The first was published back in 1925, a joint effort of the USDA and the Mass. Dept. of Agriculture’s Division of Soil Reclamation, Soil Surveys, and Fairs. Sadly, the division no longer exists, or else I would surely be a member. But this edition lacked the detail I craved.
At 144 pages, plus a granular 1:20000 scale map, the 1986 Soil Survey of Dukes County contains all of the pedological info one Islander might desire. Significant passages were written by Bill Wilcox, a towering figure in the regulation and research of Vineyard water and soil. In 1978, the Gazette described him as an “admirable bearded man.” His long presence in both areas of study helped me feel vindicated in my synthesis drought and soil in this column.
I will spare you the discussion of the geological formation of the Island and its soils. The key point is this: Most of our soil, especially down-Island, is made out of sand. Soil categorizations range from “sandy loam” to “loamy sand” to “sandy clay loam” to “sand.” Many of these soils are ominously described as “excessively drained.” When a drought comes, the water doesn’t stick around for long.
If “sandy loam” is not specific enough for you (and it certainly wasn’t for me), you can use this report to find a location specific soil series, categories with delightful names like Klej, Pompton and Berryland. According to the Map Sheet Number 14, my yard’s soil is from the rather less whimsical Carver series, categorized as “mesic Typic Udipsamments” (basically, wettish sand with a longtime plant presence). Mr. Wilcox’s calculations predict that it might yield 4 tons of sweet corn per acre.
Because I maintain a healthy distrust of government reports, and because I had nothing better to do on Sunday, I decided to test this identification by digging a hole in the backyard. My findings agreed with the Survey – first a layer of rotted forest detritus, then some grayish sand, then some bright orange sand, colored by a surfeit of iron oxide. It was dry all the way down.
But while I may have excavated Carver soil, I did not refill it. In preparation for a squash bed, I added a healthy serving of compost, upping the Soil Survey’s estimated 3 three per cent organic matter to somewhere around 40 per cent. Hopefully this new soil, unlisted in any survey yet compiled, will stay a bit wetter for the rest of the season.
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