Agriculture always impacts the environment, some of it good and some of it bad. Corporate farming, agribusiness, mono-cropping, whatever you choose to call it, is more of an act of war than an act of culture. Since the “bottom line,” of corporate farming is the “bottom line,” meaning the profit margin, it makes little or no consideration of how to work with the land and climate, but thinks more of how to conquer it.
Mono-cropping, the practice of growing one crop, or type of crop, makes its plans on the path of least resistance, meaning weeds. Soil scientists have discovered optimum growing conditions for nearly every crop; what levels of Sodium, Potassium or Phosphorous (N-P-K) is needed for each type of plant. By adjusting the soil conditions to these levels, they can minimize competition from weeds, lowering the amount of work that each field needs to bring to harvest. Weeding is the most intensive aspect of growing food, and with the sizes of these “mega-farms,” they do not have the time to weed.
However, since they minimize the weeds, they maximize the amount of excess water that may be absorbed by the soil. One of the consequences of tampering with soil conditions on a grand scale is that it impacts the other values of the soil. These include the microbes, the amount of moisture that soil can absorb, and rate at which it can absorb it. Even if the soil is still diverse enough to accept the water, the practice of tilling to the depth of a plow blade creates a “hard pan.” This is a compressed layer of soil at a certain depth, which then creates essentially a seal against water penetration. As a result, the nutrients beneath that layer are also not available to plants growing above.
Minimizing weeds, encouraging one type of crop to grow, also makes the land more attractive to some insect pests that might not find a certain area appealing if it were peppered with unappetizing milkweed, or other weeds. But because the field is one or two delicious types of lettuce, carrots, grain, etc. it is a more likely “resting spot,” for large populations of grasshoppers, locusts, beetles and other insects.
Sterilizing the soil means that the farmer is required to constantly reapply chemical fertilizers to the land, mostly through the spraying of various products. One of these is anhydrous ammonia, which makes large amounts of nitrogen available, but also has a heavy impact on the soil and groundwater pH. This in turn changes the types of microbes and decomposers that can live in the soil, also affecting the long term fertility of a piece of land.
Since repeated planting of the same crop eventually renders the field uninhabitable by the intended crop, new amendments must be added to the soil, to prepare it for a new crop. These are either tilled in, or sprayed on. Anything not taken by the plants, microbes or insects will be washed off by rainfall, or by irrigation which is often used to penetrate the soil, as liquid is easier for the soil to absorb than particles.
This “non-point runoff,” has become a major problem in the Mid-west and Northeast, heavily contributing to “Dead Zone,” in the Mississippi Delta and the general population of the Delaware and Chesapeake Bays. These are the largest concentration of shellfish in the US, yet they suffer from Mystery X virus and other diseases, due in part to polluted run off from upstream fields.
In addition to these environmental costs, there is a strong belief that we are headed for another “Dust Bowl.” As massive farms stretch across the Great Plains, they supplant the native grasses which created the network of roots, effectively holding the top soil in place. One of the reasons for the 20th century Dust Bowl was the “sod busting” and the Western expansion, which opened up the rich soil to rain, where it used to be protected by sod. The Soil Conservation Service was created to stem that tide of expansion, and to try to rebuild the topsoil. However, it has not been successful in its task, and topsoil depletion continues to expand.
These are just some of the “costs” of cheap food that most people fail to consider when shopping by the “bottom line.” There are other effects, on ground water, on overall food safety, on wildlife diversity, but those are “sexier,” and easier to understand. It is the nutrient cycle that is at the root of it all. Without that diversity, decomposition, rest and rebuilding that is inherent in sustainable and organic farming, industrial farming continues to enlarge the problems of the environment. Most of it, without anyone even knowing it’s happening.