In Part 1, we talked about the limitations of NPK fertilizers and compost in building healthy soil. We explored the primary soil minerals (Calcium, Magnesium, Potassium, Sodium, Phosphorous, and Sulfur) and the secondary soil minerals (Boron, Iron, Manganese, Copper, and Zinc). The terms primary and secondary refer to amounts required for a balanced soil, rather than a reference to their importance. As we learned in part 1, they are all important and are interdependent. The primary minerals, the alkaline or base minerals, make up the largest percentage of a balanced soil. The secondary minerals are required in lesser amounts for a balanced soil.
A word of caution – These minerals should never be added to the soil without a soil test to determine if you need additions and how much. This is especially true of the trace minerals we will examine today. These are needed and applied in very small amounts, mixed with other needed minerals such as lime, to facilitate even application. Too much of any of these will result in toxicity.
Our focus this time is on the trace minerals that are required only in very small amounts — Cobalt, Molybdenum, Selenium, and Silicon. Although required only in a few ppm per acre, their presence is critical in building soil fertility. They are catalysts and synergists that activate other minerals and functions vital to the health and strength of plants, crops, and animals.
Cobalt is a component in the production of numerous enzymes, increases drought resistance of seeds, and is a component of vitamin B12. Ruminants such as cattle and sheep produce B12 in their digestive systems when Cobalt is present in their forage. The absence of Cobalt in the soil increases their susceptibility to infections and diseases. We like to see a minimum of 2 ppm of Cobalt in the soil. Cobalt is added to the soil in the form of Cobalt sulphate.
Molybdenum is a catalyst necessary for the fixation of Nitrogen. Much of our Nitrogen needs can come from Nitrogen in the atmosphere. Molybdenum is a key component of an enzyme that facilitates the conversion of Nitrogen gas to plant available ammonium Nitrogen. Cobalt and Molybdenum work together to source Nitrogen from the atmosphere in partnership with micro-organisms. Several Molybdenum-based enzymes are key to plant stress resistance and resilience. We recommend 1 to 2 ppm of Molybdenum in the soil through application of Sodium molybdate.
Selenium is a co-factor with vitamin E, is essential for proper immune system function, is associated with resistance to viruses, and regulates antioxidant activity necessary for plant resilience. It is required to produce the most powerful enzyme protection system in humans and animals. The ideal level of Selenium in the soil is 1 to 2 ppm. We use Calcium selenate or Sodium selenate to achieve the desired ppm.
Silicon strengthens cell walls and thereby is key to pest and disease resistance. It also improves stem strength. Nutrient pathways around and into the plant are made of Silica, and adequate amounts of the mineral improve nutrient translocation (movement throughout the plant). Silicon is the second most abundant mineral on earth and is a component of clay, soil, and rocks but is not in plant available form. Mono silicic acid is the plant available form of silica. We try for 100 ppm of mono silicic acid in the soil with the addition of Potassium silicate. For a gradual, long-term release of mono silicic acid, we use Calcium silicate or diatomaceous earth.
These are just of few of the many functions of each trace mineral, their interaction with other minerals, and how they work in synergy to contribute to optimum soil fertility. There are many others that occur in soils in very, very tiny amounts such as Chromium, Fluorine, Iodine, Nickel, Cesium, Tin, and Vanadium to name a few. These and many more are found in sources such as Azomite Brand Volcanic Minerals (71 trace elements), Glacial Rock Dust (67 trace elements), Jersey Greensand, Kelp Meal (60 trace elements with the added benefit of growth stimulants), and Redmond Mineral Salt or sea salt (50 trace elements from the ocean).
Our soil test includes the primary and secondary minerals, as well as the essential trace minerals Cobalt, Molybdenum, Selenium, and Silicon.
If you want to grow the healthiest, most nutritious food possible, paying attention to the health of your soil is one of the best ways to achieve this long term. Go to the Get Started page on this website for further information and how to get started growing the most nutritious food possible.