The whole “you are what you eat” phrase applies to more than just humans: it’s true of our food, too, right on down the food chain. If you’re going to the trouble to eat fruits and veggies and whole, unprocessed grains (which you should be), don’t you want to make sure you’re getting rewarded for your efforts, in the form of nutritionally dense foods?

Soil Requirements for Healthy Plants

Plants need essential nutrients from soil just like you need them from your food—some in large amounts (macronutrients), and some in small amounts (micronutrients). Primary nutrients for plants include nitrogen, phosphorus and potassium. If you look at commercial fertilizer bags, the label will usually say N-P-K, representing these major nutritional requirements. (By the way, for humans, macronutrients are carbohydrates, protein, and fat).

Intermediate nutrient requirements are sulfur, magnesium, and calcium. Micronutrients include boron, copper, iron, chloride, manganese, molybdenum, zinc, cobalt, and nickel.

Too little of any one of them can affect the health of the plant, and its nutrient value to its consumers.

What Affects Nutrient Content in Soil

A few variables affect nutrient content in soil. One is texture: basically the more the soil holds on to water (moisture and stickiness), the more it will hold on to nutrients as well. Sand obviously doesn’t grow much (hence the barren deserts), while clay and organic soil does.

Another is pH. Just like our bodies have to maintain the right pH for life, so soil has to stay in the right pH range (6.0-6.5) to release both macro and micronutrients from the soil to the plants. Otherwise these nutrients will be bound up and unavailable. The right pH will also allow growth of microbe populations that help to convert the nutrients nitrogen and sulfur into usable forms for the plant. (By the way, you need plenty of microbes to help you with your digestion too.) 

Fertilizer: What To Do When Soil is Suboptimal

If your soil lacks either the nutrients or the pH for growth (or both), you have to fertilize. This is where the difference between commercial and organic farming comes in.

Commercial fertilizers are processed to adjust the pH rapidly and provide a walloping dose of synthetic nutrients, and they are great for giving a jump-start to very depleted soil. These nutrients are mined, chemically processed, and delivered to the soil in salt form (much like our table salt, made from rock salt). These salts release their nutrients to the soil quickly and easily when they come in contact with water.

The problem is, these fertilizers add primarily macronutrients for the plant’s use, but they don’t help the soil to cultivate those necessary micronutrients. (Think of it like a human subsisting entirely on fast food. You may be getting all three of the major macronutrients: carbs, protein, and fat, but you’re still malnourished, and it’ll catch up with you eventually.) In the same way, this means that even though the plants may grow rapidly (just like you would on a fast food diet!), over time the soil gets depleted of its micronutrients. Maybe the first generation of plants grown in that soil will have all they need, but eventually those micronutrients get consumed and the soil will thus become unhealthy. This means future generations will lack those micronutrients necessary for the health of the plants, and they’ll pass these deficiencies on to you.

If that weren’t enough, sickly plants also tend to become targets for pests, which makes pesticides increasingly necessary (many of which are toxic to humans. As a side note on this: notice that the healthier the soil, the more easily they repel pests on their own, just like healthy humans will require far less outside assistance to prevent illness. Antibiotics, like pesticides, will work in a pinch… but they aren’t dealing with the underlying issue, which is why the susceptibility exists in the first place.)

Genetically modified foods (GMO) try to get around the pest issue by adding pesticides directly to the genetic code of the plants… but among other potential problems, evidence demonstrates that GMO foods bind micronutrients such as manganese, zinc, and iron. (Not only is the soil deficient in them, but now what is there isn’t available either.) This means sickly plants, sickly animals who eat the plants (since many commercial farming animals are fed from GMO corn or soy), and sickly people who eat those animals.

The Alternative: Organic Fertilizers

Organic fertilizers are created from “natural” substances, rather than in a chemistry lab. These include things like compost, animal manure or guano, blood meal (from powdered blood), fish meal (from ground up fish), bone meal (what it sounds like), and that sort of thing. (So if you think about it… organic plants are sort of carnivorous!)

Because these nutrients are bound up in complex molecules, though, it takes time for soil organisms to decompose the organic fertilizers enough to release the key nutrients into the soil. Really depleted soil will appear to respond much faster to synthetics for this reason, but that approach doesn’t aid the health of the soil and the plants in the long run. It’s much better to build up the soil with compost, and then fertilize it with organic materials containing all the necessary micronutrients.

Does Organic Farming Make More Nutritious Food?

This comprehensive study in Science Daily says yes: organic foods come out more flavorful and significantly more nutrient-dense than their conventional counterparts, and the soil is healthier for future crops to boot.

The Take-Home Message:

If organic foods are available and affordable, buy them. Not only are you minimizing pesticides, herbicides, and GMO foods, you are maximizing nutrient density and longevity of the soil for future crops.

You’re also “voting” with your dollars: commercial farming can be done on a large scale, with high yield, and is therefore more cost-effective than organic farming. But the market responds to demand. These days, organic foods are popping up even in big box stores. If we insist on nutrient-dense food, more and more of it will become available to us.

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