Principles (continued)

Natural Plant Nutrition

Even though we require the same basic “stuff” to live, it is somewhat challenging to draw simple comparisons between the nutritional needs and processes of plants and those of animals. Plants are able to photosynthesize to make sugars, which are ultimately synthesized into proteins and other plant constituents. Humans and other animals, by contrast, can obtain energy foods, proteins, and vitamins only by consuming plants or other animals.

Both plants and animals also require minerals. Humans and other animals extract minerals, along with sugars and proteins, from the food they consume and digest. Plants, too, obtain minerals—and a wide range of vitamins, antibiotics, and other useful compounds—through digestion. However, plant digestive systems are not internalized as they are in animals. Plants must rely on the external digestive processes of the soil system within reach of their roots—a zone called the rhizosphere.

The organic philosophy of crop nutrition begins with proper care and nourishment of the organisms responsible for the soil digestive process. Organic farmers believe this is best accomplished by avoiding toxic chemicals and practices—like excessive tillage—that are harmful to soil organisms, as well as by the addition of organic matter and natural rock minerals. Conventional systems, in contrast, try to circumvent the soil’s digestive process and provide needed minerals to the plant directly, in a soluble form.

From the organic perspective, the conventional approach has several flaws. Organic proponents generally believe:

· Applying a large quantity of soluble fertilizer to a crop only one, two, or three times per season floods the plant with those nutrients, causing nutritional imbalances that lead to crop diseases, insect infestations, and reduced food quality.
· Failure to support and care for soil biotic life, along with other practices that are downright destructive, ultimately leads to its decline. As a result, plants
lose out on the vitamins and other beneficial products these organisms produce, tilth is reduced, and the soil becomes increasingly dependent on synthetic inputs.
· Conventional fertilization tends to concentrate on a limited number of macronutrients, even though the need for at least 13 soil minerals is scientifically recognized. This skewed focus is also considered responsible for generating imbalances in the plant.
· Application of large amounts of soluble nutrients is believed to stimulate certain problem weed species.
· Soluble nutrients—especially nitrate—are prone to leaching which can cause a number of environmental and health problems.

It is organic farming’s approach to soil building and plant fertilization that is the true basis for the belief that organic food and feed has superior nutritional value, much more so than the absence of pesticide residues which has drawn the spotlight ever since the 1960s.

Critics are often under the illusion that organic farmers believe plants obtain all their nutrients from an organically managed soil in a chemically organic form. While a few organicists may believe that, the majority recognizes that digestion processes in the soil release minerals in forms similar to those applied as commercial fertilizers. Unfortunately, the notion that organic farmers are naïve and ignorant about basic agronomy is a red herring that has often foiled intelligent discussion about the pros and cons of the system.

Among the facts that are often obscured is the reality that plants can and do absorb significant amounts of large organic molecules from the soil; herbicide and systemic insecticides are among these. In healthy soils they also absorb vitamins, chelated minerals, hormones, and other beneficial compounds (16).