“Our most important job as vegetable gardeners is to feed and sustain soil life, often called the soil food web, beginning with the microbes. If we do this, our plants will thrive, we’ll grow nutritious, healthy food, and our soil conditions will get better each year. This is what is meant by the adage ”Feed the soil not the plants.”  – Jane Shellenberger,
The underlying principle adopted at groSMARTLawnandGarden.com recognizes soil as a living, dynamic and ever-so-subtly changing ecosystem. We are committed to advancing programs and products designed to improve and maintain soil health.
Fertility Components of Soil  
Biological Fertility 
Soils are alive! A variety of soil organisms live in the soil.  These include bacteria, fungi, micro-arthropods, nematodes, earthworms and insects. These organisms live on soil organic matter and perform vital processes in soil.   Very few soil organisms are pests.
Chemical Fertility 
Concerns the availability of elements for plant uptake as well as the presence of elements and compounds present at levels potentially detrimental to plants and soil organisms.  Some elements in the soil are nutrients and are essential for plant growth.   The availability of elements for plant uptake is affected by soil pH and reactions of the elements with soil particles and organic matter.
Physical Fertility   
Physical properties and processes of soil affect soil fertility.   Physical soil characteristics important to soil physical fertility include:

  • Soil structure.
  • Soil texture.
  • Water repellence.

Important physical properties that affect fertility include soil structure and texture.
Structure is the amount of aggregation and pores in soil. Texture is the proportion of clay and sand particles in soil.  Both affect soil fertility by affecting water movement through soil, root penetration and water logging.  When soil structure and texture are unfavorable for water movement through soil water erosion and waterlogging may be increased.
Soil salinity is a chemical property but can affect soil physical fertility by decreasing the movement of water through the soil.
Good soil structure is one of the major factors for soil health and sustainable soil fertility.  Good soil structure is present when the soil forms stable aggregates or cohesive groups of particles producing pore spaces which encourage root penetration and easy passage of water, nutrients and air.
The Role of Soil Organisms in Soil Fertility    

  • Helps soil to form from original parent rock material.
  • Contributes to the aggregation of soil particles.
  • Enhances cycling of nutrients.
  • Transforms nutrients from one form to another.
  • Assists plants to obtain nutrients from soil.
  • Degrades toxic substances in soil.
  • Causes disease in plants.
  • Minimizing disease in plants.
  • Assists or hinders water penetration into soil.

Soil Organic Matter (SOM) is Critical to Soil Health & Performance 
The number one driver of a healthy soil – Soil Organic Matter.   Many things effect soil health, or non-health.  Some are inherent properties such as texture, mineralogy, depth (to bedrock or other restrictive layer), geographical climate (precipitation, temperature), rocks, and land form/aspect.
These conditions or properties are quite difficult to change.  However, ALL of them can be modified to some extent by human manipulation.
SOMis what we strive to increase as much as possible because it has so much influence on virtually every other factor, property, or indicator of soil health,   If your SOM levels (and biological activity) are high, all other balances (systems, processes, cycles, etc.) seem to “self regulate”.
Organic Matter – What is It? 
Organic matter is anything that contains carbon compounds formed by living organisms.
Includes things like lawn clippings, leaves, stems, branches, moss, algae, lichens any parts of animals, manure, droppings, sewage sludge, sawdust, insects, earthworms and microbes.
There are 3 main components of organic matter in soils:

  • Dead forms of organic material – mostly dead plant parts
  • Living parts of plants – mostly roots
  • Living microbes and soil animals.

What is the Impact of Incorporating Organic Matter? 
Doing so disturbs the physical, chemical and biological balances in the soil. It can change the:

  • Amount of nitrogen that is available to plants, the way soil sticks together (soil aggregation) and the number and type of organisms present in the soil.
  • Incorporating organic matter into soils can change the amount of nitrogen (and other nutrients) that is available to plants.
  • Adding organic matter can also increase the activity of earthworms, which in turn can also improve soil aggregation.

If organic matter is retained in the soil, the number of microbes in the soil increases because the microbes can use the organic matter as a source of energy allowing them to grow and multiply.