So you would like to have a minerally balanced soil for optimum fertility? It will require an investment, but that investment will pay big dividends. Optimum mineral balance in the soil will result in:
- Increased nutrient density in the food and livestock forage you grow
- Natural disease and pest resistance
- Increased yield
- Improved soil tilth and friability
- Improved water retention and drainage
- Reduction in weed problems
- Reduction in fertilizer inputs
- Retention of Carbon and Nitrogen
- Ideal pH for your soil and climate
In the long run soil mineral balance will save you money by:
- Reducing the need for additional fertilizers
- Reducing water usage and providing protection in drought conditions
- Reducing pesticide and herbicide use
>Additionally, you will be providing the highest quality, most nutritious produce, dairy, and meat possible for your family and customers.
The investment required to achieve such results consists of a soil test, a soil Rx based upon the results of that soil test, and the soil amendments needed. The quantity of minerals and amendments will depend on the condition of your soil, and how deficient the soil is in eleven primary and secondary mineral elements. For example, many soils in the United States are very Phosphorous deficient. Certified organic requires the use of amendments approved for organic use by the USDA National Organic Program.
Everything In Balance
The primary elements that are required in optimum levels are Sulfur, Phosphorus, Calcium, Magnesium, Potassium, Sodium, Boron, Iron, Manganese, Copper, and Zinc.
Not only are we concerned with optimum levels of these minerals, but also their ratios to each other. Justus Von Liebig, considered the founder of organic chemistry and regarded as one of the greatest chemistry scientists of all time, made major contributions to biological and agricultural chemistry. He popularized the “law of the minimum” which states the availability of the most abundant nutrient in the soil is only as good as the availability of the least abundant nutrient in the soil. To put it another way, a plant’s genetic potential is limited by the nutrient in shortest supply.
For example, too much Phosphorous restricts Zinc. Magnesium can stimulate the uptake of Phosphorus, while excess Potassium can inhibit uptake. If the Calcium level is too high in relation to Magnesium, the soil will be loose but will lose its texture and cohesiveness and water may drain through too easily and be lost. It will also be more prone to erosion from wind or water. If the Magnesium level is too high, the soil will be tight, preventing water and air from moving through easily. Too much Potassium restricts, or ties up, Boron and possibly blocks out the Manganese. High Copper shuts down Phosphorus, Zinc and Iron.
An optimum level of Sulfur is critical to the retention of Nitrogen and Carbon. Without adequate Sulfur, much of the ammonia Nitrogen generated by the breakdown of organic matter will be off-gassed into the atmosphere and be lost. Much of the Carbon will be lost as well as it is off-gassed as Carbon dioxide. (CO2). These are just a few examples of why ideal mineral quantities and ratios are so important. Rather like Goldilocks and the Three Bears, we want it just right.
Minerals and Human Health
If the minerals are not in our soils, they can’t be in our food. The secondary elements (secondary not in importance but in quantities required in relation to the primary elements) of Iron, Manganese, Copper, and Zinc play a vital role in health. Iron is essential for transporting Oxygen in the body and for the formation of red blood cells. It also supports the immune system and regulates growth. Manganese works in synergy with other minerals to promote immune system functioning. It is also necessary for reproduction, blood clotting, and for healthy skin, nails, and hair. Copper combines with certain proteins to produce enzymes that act as catalysts for skin pigmentation and the formation of collagen to maintain and repair connective tissues, including the heart and arteries. Zinc is the “reproduction and intelligence” mineral essential to neurotransmitter functioning and the maintenance of cognition. It is found in every tissue in the body and is essential for protein synthesis and cell division as well as being a powerful antioxidant. Zinc protects against neurodegeneration and the development of Alzheimer’s disease. Most agricultural soils in the United States are severely Zinc deficient.
One can see the necessity of these secondary minerals to human health. They must be in the soil in optimum quantities, and in balance, if they are to be in our food and in our bodies.
Insoluble But Available
Calcium, Magnesium, Potassium, Sodium, Iron, Manganese, Copper, and Zinc, are cations (KAT-eye-ons) and have a positive ionic charge. They are held on negatively charged exchange sites primarily in the clay portion of the soil, but also on the organic matter or humus portion of the soil, by an electrostatic bond (opposites attract). Sulfur, Phosphorous, and Boron are anions (AN-eye-ons) having a negative charge and are primarily complexed with humus (organic matter), which has both positive and negative charges. Boron and Sulfur (and even some Copper) can be subject to some leaching.
However, as organic matter increases, more Boron and Sulfur will tend to adsorb to the organic matter and thus remain in the soil and available to plant roots. Conversely, soluble synthetic fertilizers leach into ground water and run off into rivers, lakes, streams, and eventually into the ocean.
The exchange capacity of the soil is its ability to hold on to and release mineral nutrients. Put another way, it is the soil’s “gas tank.” A soil with a large gas tank will take you a long way. A soil with a small gas tank will need to be refilled more frequently. Both can be balanced for optimum fertility. The initial cost of bringing a soil into balance will depend on the size of its gas tank. The exchange capacity of a soil (the size of its gas tank) will determine the initial cost. A soil test will tell us the size of the gas tank. That is always where we begin.
Cost Range Per Each Soil Rx
The total cost of treating a garden, field, or pasture depends on how big the soil’s gas tank is, the total square footage or acreage, condition of the soil, what it is deficient in and the degree of deficiency, freight for bulk quantities, your geographic location, and prices for soil amendments from your local sources.
The cost of a soil test is $30. The cost for writing a soil Rx is $50. The cost of any additional consulting is $50 per hour. The cost of soil amendments can range from $0.05 per square foot to $0.32 per square foot inclusive of freight.
|Each soil test||$30.00|
|Each soil Rx||$50.00|
|Soil amendments including freight||$0.05 per sq.ft. to $0.32/sq.ft.|
The cost of an ideal soil of optimum fertility does indeed require an investment. However, once the soil has been amended and brought into optimum balance, you will not have to amend in these quantities again. The soil will have everything needed for years to come. Yearly maintenance will involve the addition of Sulfur and Boron, two minerals that are readily taken up by plants and subject to some leaching.
By investing in “soil building” you will realize the most nutritious produce, forage, dairy, and meat possible. Your products will taste superior, be of superior quality, and therefore will command a premium price. Your family and your customers are worth it.
Next time, we’ll examine one of the gardens we’ve been working on over the course of two years, and share more details about investment and results.