The Practical Gardener

Henry Ford dramatically changed the lives of Americans. He brought tourism and commuting to ordinary folks. He brought the assembly line to manufacturing. And you could argue that he created the need for artificial fertilizers.

One of Henry’s crowning achievements was a marketing scheme that was, at once, both inspired brilliance and evil genius. Ford offered this deal: Bring in your mule or your horse and trade it in for a new car. The heretofore beasts of city and farm were slaughtered by the hundred thousands. Ford suffered a short-term loss to create a multi-generational need for his product.

When America lost the horse, she also lost horse manure. In 1900, there were a hundred thousand horses in Manhattan alone. The daily mountain of manure was trucked outside the city to vegetable farmers, to be aged in piles before being applied to fields as fertilizer. This was about the only realistic way to get rid of the never-ending accumulation of waste. I’ve read descriptions of old truck farms that grew crops in soil several feet thick, built up by years of applications of composted manure. With Ford’s deal of the century, that daily mountain of manure disappeared, not just in cities, but all across America.

About a decade after the 18-month period in which Henry Ford traded cars for dog food, chemical fertilizers started showing up on farms. Given the absence of an unlimited supply of low-cost fertilizer, coupled with farm crops’ year-after-year drain of nutrients, an artificial fertilizer made all the sense in the world.

Chemical fertilizers, unlike synthetic pesticides, don’t taint produce with toxic residues. And for the most part, produce raised on chemical fertilizer isn’t toxic to humans. There are some downsides. Blind taste-test studies have demonstrated that chemically raised produce doesn’t always taste as good as organic produce. And chemically-fed crops have been shown to alter the vitamin and protein content of some crops. But the big problem is that chemical fertilizers are darn destructive to the soil.

The problem with using a little 10-10-10 is that it ignores the soil’s structural needs. In the natural world, plants grow and die; they lay on the ground as mulch, and then slowly decompose into humic matter (the lowest common denominator in organic matter). Each year, plant descendants repeat the cycle. It is a self-contained circle of fertility. If the plants look happy in an untouched setting, it isn’t an accident; it’s because they can satisfy their own needs in the soil, where they reside, die and rise up again.

As plants live and die, they feed themselves, but they do so by feeding the soil and its millions of microorganisms. The organisms break down the dead plants, turning them into organic matter, and in so doing, give soil its structure. Structure is what soil needs to retain water and to provide the habitat for microorganisms. When soil loses organic matter, it becomes structurally deficient. And without structure, the tiny inhabitants die (or the wrong ones flourish).

The first great failure in chemical fertilizers is that they remove the need for organic matter. Without organic matter, soil loses its structure and simply becomes a holding medium for crops. Without the structure that organic matter provides, soil looses its friability.

The second great failure in chemical fertilizer is its toxicity to microbial life. Chemical fertilizers are highly soluble. Some studies show that as little as 20 percent of the nutrients in chemical fertilizers are used by plants. The rest runs into the ground. The high acid content of artificial fertilizers creates a toxic flush that kills off microorganisms in the soil.

In the underground microscopic world, during the normal course of events, the bodies of dead microorganisms have their ecological function. After dying, the matter from their bodies is transformed into cementing material that binds tiny particles of rock and organic matter together to form soil crumbs. However, the acid content in chemical fertilizers dissolves this beneficial cementing material, further destroying the soil’s structure.

Additionally, various minerals and compounds, such as sodium, accumulate in the soil as chemical fertilizers pass through.

These changes turn the soil into a cement-like hardpan that is impervious to water.

Henry Ford took a short-term loss and created a long-term gain for the auto industry. But in so doing, he gave a huge boost to the chemical-fertilizer industry. The result was a short-term gain for them and a long-term loss for agriculture.

So what does it take to rebuild your garden’s soil structure? Take a short-term loss: Invest some labor and resources to add organic matter, and you will reap the long-term benefits of improved water retention and better-tasting crops.