Compost for Healthy Soil
Using Compost for Soil Health
Soil health is more complicated than just N-P-K. Three aspects of soil are important to soil health:
Physical Soil Health
The physical condition of the soil, including texture (sand, silt and clay), density, porosity and hardness, is important. This can be evaluated with a shovel, penetrometer or even a garden trowel. Evaluate both the surface (1-3″) and subsurface of the soil (4-6″). The physical condition of a soil affects its ability to exchange nutrients into plant available form; allows for respiration and digestion processes by soil organisms; and enables (or restricts) root penetration. Everything that follows is affected by this basic characteristic of the soil.
Biological Soil Health
Biological processes within a soil are crucial to its ability to support plant life in a sustainable manner. It involves:
An assessment of the living organisms within the soil. Basic observations relating to earthworms and similarly-sized critters, their pathways and other evidence of their activity are important. You can observe these signs when using your shovel and assessing the physical characteristics explained above.
Smaller microorganisms that you can’t see are crucial to converting organic matter into plant available nutrients. Over time, with air and moisture at the proper balance, organic matter is converted biologically (literally by digestion) into plant-available chemical nutrients.
Chemical Soil Health
This component of soil health is what the plant really cares about. The macro and micro elements required by different plants in different available quantities and sometimes ratios to other nutrients greatly affects the desirable plant’s ability to thrive. Primary (macro) elements include:
• Nitrate nitrogen
Different factors affect the proper balance and ratios of plant nutrients.
Soil pH is not a nutrient. It is an estimation of free hydrogen in the soil, which (in simple terms) greatly effects the availability of macro and micro nutrients.
For example, iron (Fe), aluminum (Al) and manganese (Mn) are micronutrient metals in the soil and are tied up at high pH. Plants that prefer low pH will exhibit a symptom called “iron chlorosis” if the pH is too high. Conversely, in plants that prefer higher pH, acidic soils will result in too much available iron and aluminum and resulting in a condition that is toxic to their emerging roots.
pH plays an important role in microbial nutrition as well. Therefore, a chemical soil test that provides pH level and concentrations of the macro nutrients can be quite valuable when managing crops.
The key to soil health is optimizing nutrient availability in the right ratios, according to your desired plants or crop.
This availability is driven by all three of these factors – the Physical, the Biological and the Chemical.
Composts and Soil Health
The use of compost and organic soil amendments in general can greatly benefit your soil’s health. When selected and used properly, they can affect each and all of the components detailed above at the same time.
When soil problems arise, the first solution is likely to be compost.
Compost is the answer to most soil texture and fertility problems.
Compost feeds the living organisms in the soil for the long term (unlike chemical fertilizers that are the equivalent of a “quick-fix drug”).
Compost retains soil moisture while preventing poor drainage.
Compost retains air pockets in the soil.
Compost has some disease-prevention and disease-fighting potential.
Compost making is an ancient skill — from Egypt to China, farmers and gardeners have blended organic materials (food scraps, coffee grounds, seaweed, leaves, manure, straw, etc.) and aged piles of these materials. Then they used the humous-like product called compost, to make soil workable and highly productive.