What is the Soil Food Web?

 Photo credit: unknown

Photo credit: unknown

The soil food web refers to the complex relationships between the diverse groups of fauna and flora found in soil. These groups include bacteria, fungi, protozoa, nematodes, microarthropods, and the larger plants and animals found in and around soil. The composition of each specific web is greatly influenced by biological, chemical and physical forces in the environment.

The practice of soil food web health management (SFWHM) was developed by Dr. Elaine Ingham, a respected soil microbiologist. Her research over the past three decades has greatly broadened our understanding of how life in the soil affects the health of plants. The most significant finding is that plants thrive best under the specific soil food web that it had naturally evolved under over millenia. Hence, SFWHM emphasizes the cultivation of soil food webs that are specific to the plants of interest for maximum plant health.


Why is it important?

A healthy soil food web offers great ecological importance to all landscapes, ranging from small backyard gardens to old growth forests. Soil contains countless microorganisms continuously performing varied functions that help maintain healthy ecosystems. When we improve the biology in the soil, we are promoting vital ecosystem services that are used by society at large.

Such services include:

 microarthropod in worm bin.  October 2015; microscopic image taken by Jo tobias

microarthropod in worm bin.  October 2015; microscopic image taken by Jo tobias

  • Decomposition of organic matter
    • Bacteria and fungi are the major decomposers in soil.  Soil animals such as mites, millipedes, earthworms and termites aid in the decomposition process by shredding the organic material and dispersing microbes throughout the soil.  This community of decomposers play a crucial role in waste management and pollution control.
  • Nutrient cycling
    • When predators such as protozoa and nematodes exist in soil, their faecal excretions from consuming bacteria and fungi release nutrients that plants then absorb. These nutrients are often necessary for plants to flourish. The presence of these predators result in the elimination of any need for chemical fertilizers.
  • Retention of nutrients
    • Nutrient leaching refers to the loss of nutrients in the soil due to movement of water down through the soil. Bacteria and fungi prevent nutrient leaching by storing the nutrients in the soil in their bodies. Thus, soil that is rich in these organisms are more resistant to nutrient leaching. Conventional industrial farming relies heavily on salt-based fertilizers that not only kill bacteria and fungi, but also pollute the surrounding watershed.
  • Bioturbation
    • The movement of gases and water into and through the soil is important for life within the soil. This is achieved primarily through bioturbation, the process of creating channels within the soil through the activities of organisms such as ants, earthworms, termites and plant roots.  Increased bioturbation has been linked to increased decomposition of organic pollutants in soil.
  • Disease suppression
    • Soil that is abundant with a diversity of microorganisms reduces the viability of plant and human pathogens in the soil.
  • Toxin decomposition
    • In aerobic conditions, bacteria decomposers can break down pesticides and pollutants in soil
    • Fungi degrade and sequester contaminants in the environment. A practice called “Mycoremediation” is a form of bioremediation which utilizes fungi as the major decomposer of toxins.

What Now?

Soil provides the physical substratum for virtually all human activities, like agriculture, buildings, transport; it provides resources for industrial use and waste management; and it is central in elemental cycles, without which agriculture would not be possible.
— Biodiversity and Ecosystem Functioning in Soil; Brussard, Lijbert
 pLANT roots by christophe jacquet; metabolomics in the rhizosphere tapping into belowground chemical communication; trends in plant science

pLANT roots by christophe jacquet; metabolomics in the rhizosphere tapping into belowground chemical communication; trends in plant science

The importance of soil microorganisms cannot be overstated. Virtually every facet of our daily lives requires, directly or indirectly, the work of microorganisms; from the food we eat, the water we drink, the materials we consume, the clothes we wear, the air we breathe.

Current mainstream practices typically destroy the life in the soil and cannot be maintained indefinitely.

If we are to have any hope of enduring as a species well into the future, we would be wise to bring back and maintain biological diversity in our soils, and acknowledge the complex processes that occur beneath our feet.


RootShoot's role in Soil Health

A bacterial-feeding nematode.

RootShoot provides microscopic soil analysis that allows one to better understand their soil. Soil food web health can be determined for any scale of plant production, from planter pots to massive farms. Through our analysis, we can help you determine if your soil is compatible in terms of biological diversity to support your desired plants.


References

[Soil FoodWeb Incorporated][1]; Dr. Elaine Ingham

1 Biodiversity and Ecosystem Functioning in Soil; Brussard, Lijbert

Teaming with Microbes; Jeff Lowenfels & Wayne Lewis