What is Soil Health?

Soil health has been defined as:


“The continual capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain biological productivity, promote the quality of air and water Environments and maintain plant, animal and human health” (Pankhurst et al.,1997).


A more recent definition by FAO members (2008) is a more broad explanation of soil health:


"Soil health is the capacity of soil to function as a living system, with ecosystem and land use boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Healthy soils maintain a diverse community of soil organisms that help to control plant disease, insect and weed pests, form beneficial symbiotic associations with plant roots; recycle essential plant nutrients; improve soil structure with positive repercussions for soil water and nutrient holding capacity, and ultimately improve crop production. A healthy soil does not pollute its environment and does contribute to mitigating climate change by maintaining or increasing its carbon content."


What are the benefits of a healthy soil?
Healthy soils have many benefits. One of the most important benefits is that healthy soil holds more water (by binding it to organic matter (OM)), improves water use efficiency, and loses less water to runoff and evaporation. As OM increases, it will hold up to 20 times its weight in water.


What are the basic soil health principles to build soil health?
Five principles have been reported to be the most important components to Accomplish healthy soils:


1. Minimize mechanical soil disturbance
2. Keeping the soils covered at all times (armor the soil)
3. Growing a living root year around
4. Increase plant diversity above ground to increase diversity below
5. Incorporate livestock grazing


1. Minimize mechanical soil disturbance
Physical soil disturbance such as tillage and overgrazing can result in significant disturbance of the soil physical, chemical and biological properties. Soil microbial activities are disrupted and limit their capacity to promote crop development.

 

2. Keeping the soils covered at all times (armor the soil)
Bare soil increases soil temperature. It can decrease and kill soil biological activities. Vegetation, plant residue and organic mulch protect the soil surface and feed billions of micro-organisms which recycle nutrient and combat pest infestation to plant roots. Those micro-organisms also create soil pores where more roots can
find air, nutrients 
and water.


3. Growing a living root all year
Living roots will provide a food source for soil microbes (beneficial bacteria and mycorrhizal fungi). They also contribute to the formation of soil aggregates.


4. Increase plant diversity above ground to increase diversity below
Increasing plant diversity is connected with soil root diversity. Studies have shown that specific soil microbes require specific plant types. Soils are more productive when there are more diverse microbial activities in the soil. Plant diversity through rotation and cocktail cover crops will support balanced and diverse soil populations that might reduce weed and pest infestations.


5. Incorporate livestock grazing
Land responds positively to the presence of livestock, provided management is appropriate. Farmers have found that using rotational grazing is the fastest and most economical way of improving the soil health. The microbial population also increase and stimulate nitrogen-fixing bacteria activities. Addition of manure and urine to the soils recycles nutrients. It is important that the grazing system will allow adequate rest for the plants between periods of grazing


One of the primary goals to improve soil health is to increase more organic matter in the soil for feeding the microbes. These microbes will help to improve soil organic matter which captures and holds more water and nutrients, growing more and larger plants that can gather more sunlight to power the process. This constant recycling is dependent on management of the land. Following these five principles will allow the site production to increase its productivity.