Soil Chemistry

Determining your soil chemistry is a simple task after you have a your soil tested. Your test report will serve as a blue print to assist you in building the correct conditions for your favorite plants. It is simply a matter of amending it with the missing components in the correct amounts. Visit the Soil Testing page for additional information.

The following are the basic elements that your test will reveal.


Up to ninety eight percent of all plant of growth comes directly from organic matter.
Not enough OM and your crops growth and health is limited from the very start. OM supplies many nutrients for development and stimulates the propagation of micro organisms, earth worms and other beneficial creatures. OM contains microbes which secret organic acids and help release nutrients, as well as polysaccharides that "glue" particles into stable aggregates. The end result is abundant microbial activity that improves the overall structure, resists compaction and increases air penetration. An organic matter level of five percent is a good goal to work for. This is one component of soil that you are not likely to ever have too much of, so don't worry about having even higher levels.

To supplement low OM levels use compost that you have made or a commercialy available brand from your garden center or nursery. I like Nature's Blend, cotton burr compost. It is available straight up or custom blended. This is also a good time to start thinking about starting your very own compost pile or beginning a bokashi bucket to help supplement your soil as well as recycling your organic waste.

Testing has shown compost to be loaded with nutrients and beneficial micro-organisms. (Bacteria, Fungi, Nematodes and Protozoa) These microbes secrete organic acids which help release nutrients contained on soil particles and polysaccharides that glue soil particles into stable aggregates. The end result is abundant microbial activity that improves the overall structure, increases air penetration and resists soil compaction.

These microorganisms also occupy most of the leaf or root surface and thus are most effective at consuming the food resources that disease causing organisms would otherwise consume.
In the soil bacteria have the additional benefit of retaining nutrients such as N, P, K, S, Ca etc. Bacteria also decompose plant toxic materials and plant residues and builds aggregate structure. The smallest building blocks of it's structure are built by it. Without it, the bricks that hold the soil house together would not occur and further development of soil structure will not happen.

PHOSPHOUS (P) is the "Boss" It controls root, seed and flower development in plant life, as well as the processes of cell division and sugar formation. Sugar levels regulate the plant’s susceptibility to insect and disease.

POTASSIUM (K) is the universal helper. It stimulates rooting, photosynthesis, chlorophyll formation, starch formation and sugar functions. Adequate levels of K reduce susceptibility to insect and disease outbreaks. Low test levels indicate the need for K fertilization, especially where a low cation exchange capacity is present.

MAGNESIUM (Mg) is considered a secondary macro nutrient. The chlorophyll molecule is built around the atom on Mg so this nutrient is essential to plant growth and viability. Excessive Mg can cause nutrient deficiencies. The result is lifeless, sticky mess that becomes easily waterlogged during rainy periods and will not absorb water when it has become hard during dry times.

CALCIUM(Ca) is considered a secondary macro nutrient but it is considered the most important element for the following reasons. Ca helps to form stable aggregates which give it structural capacity to hold nutrients and absorb water and air. These characteristics promote prolific microbial growth and earthworm activity. Ca helps to neutralize toxins, assists in root development and carbohydrate movement as well as being involved in protein synthesis and reproductive tissue.

pH LEVEL, is an important factor in maintaining the health and overall condition of your organic garden. For lawn and turf applications it's even more critical. If the pH level is too low, roots are unable to absorb the needed nutrients. You can fertilize but it will not help much at all. Use lime to raise you pH. It is readily available and easy to do!

This level is directly related to the level of Calcium (Ca) in your soil, which is why lime is added to raise the level. Ca is considered the second macro-nutrient, however it is the most important element nutrient for a couple of reasons. First of all it helps form stable aggregates that give it the structure requirements for holding nutrients. Second these aggregates allow water and air permeation. Then they promote prolific earthworm and micro-organism activity. These smallest of creatures are the foundations of the food web. Without them the Earth it would be sterile and incapable of supporting plant life. As Calcium is used up, the level drops below 7.0 and becomes ‘acidic’. When you add lime (nutrient fertilization) you raise the level.

It is a measure of the balance between hydrogen ions and ions of the base elements called cations. Areas that are acidic typically has an extra hydrogen ion on the roots. This 'binds' the roots from absorbing the nutrients. Adding Ca (lime) neutralizes this effect and allows proper growth. This is why test results that indicate low levels often show very high levels of Phosphorus.

If test results show that the soil is also low in Magnesium (Mg) then a dolomite lime is recommended, otherwise continue to use calcitic lime. For situations where Ca is low but P is sufficient you can spray Liquid Lime as a foliar feed to instantly supply Ca for the plants.

CATION EXCHANGE CAPACITY(CEC) is a measurement of the ability for holding cations (Ca, Mg, K, and Na). This capacity is influenced by the amount of clay and humus present. It is measured from 0 for pure sand to 100 for pure humus. High quality soils range from 18-25 the best getting as high as 35. If your have a high CEC value it is holding a lot of nutrients which can be released for plant and microbial growth.

It's all about balance. Your goal is to begin the process of bringing all the key elements into balance so it will be perfect for growing healthy plants and produce.

For help in determining what you need to add to your soil to correct problems revealed in your soil test report please refer to the guide listed here.

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