Soils vary in physical and chemical composition. The average handful of soil contains billions of different living organisms that carry out various functions to help facilitate plant health, regardless of the soils property. Organisms include larger creatures like earthworms and nematodes, to microscopic organisms including, bacteria, fungi, algae and protozoa. These organisms play a critical role in maintaining soil health and fertility.
Plants have thrived without human intervention for millions of years. However, to maximize growth and crop yields plants typically need a combination of three basic macro-nutrients – nitrogen, phosphorous and potassium. In addition, plants require a slew of other nutrients throughout their growth cycle.
The majority of a plant’s nutrients are derived from beneficial organisms working in the soil surrounding the plant’s roots; this process is known as the soil foodweb (a term made popular by Dr. Elaine Ingham, a leading microbiologist). In addition to supplying nutrients to plants, organisms benefit plants in a variety of other ways, including:
- Retain nutrients in the soil, preventing them from leaching
- Compete with, inhibit and consume diseases
- Decompose plant residue, toxic materials and pollutants that kill plant roots
- Form soil aggregates that improve water infiltration, root penetration and water-holding capacity of the soil
Once the nutrients are available, soil organism’s aid in a process known as mineralization, which is where nutrients are broken down and returned to their mineral forms. This allows the plant to take in the nutrients as needed.