Soil Health

“Soil health”  is a term often used to define the ability of a soil to function. It focuses on all three primary soil properties: the physical, chemical, and biological components and how they affect plant productivity.  By testing soil health parameters, we can better understand the limitations and stressors to a soil system, and try to adapt management practices to increase the areas that require improvement. The chemical, biological, and physical properties of soil work cohesively together.

Maintaining soil health is crucial in being able to continue to grow crops now and for the future. Minimizing soil loss and erosion will help create a sustainable area to grow while also retaining all the nutrients possible to grow the best possible food. If the soil is not maintained then the crops will not produce a high yielding crop. 

Crop rotation policies  

Soil Health Indicators: 

1. Soil texture: Soil texture is presented as the percentage of sand, silt, and clay particles found in a soil.  Based on those results, your soil falls into one of several soil texture classes. 
2. Soil organic matter: One of the best indicators of soil health is soil organic matter content. Soil organic matter, measured as total soil carbon, represents the amount of carbon compounds in the soil that are derived from living and dead organisms and plant tissues. Organic matter exists in various stages of decomposition and is considered vital to soil health because it influences almost every important soil property, including fertility, nutrient cycling, water storage and infiltration, and extreme weather events.
3. Active Carbon: Soil organic matter can be divided into two different groups: the “stable” fraction and the  “active” fraction. The “stable” (or “humus”) fraction has formed over thousands of years, is resistant to breakdown, and not usable by plants. It stores carbon and provides an essential role in maintaining soil structure and cation exchange capacity. The “active” soil organic matter fraction is more recently formed (1-5 years) and is more readily available to plants. The active fraction consists of decomposing plant and animal (microbe) tissues and acts to supply and recycle soil nitrogen.
4. Soil Respiration: Microbes, including bacteria and fungi, play a critical role in regulating the carbon cycle and mineralizing nutrients, turning them into plant-available forms.
5. Aggregate Stability: Soils are composed of many shapes and sizes of particles (sand, silt, and clay), and these particles form into structures known as “aggregates.” These aggregates of soil particles are held together by organic matter, microorganisms, and the compounds these microorganisms produce. Having aggregates of different sizes results in spaces (or pores) between the aggregates, which allows water and air to move through the soil. The structural stability of soil is dependent on how well these aggregates are held together and by the types of particles present in the aggregate. Therefore, the presence and durability of aggregates is key to maintaining good soil structure.
6. Soil Respiration: Microbes, including bacteria and fungi, play a critical role in regulating the carbon cycle and mineralizing nutrients, turning them into plant-available forms.
7. Biological Nitrogen Availability: Nitrogen is stored in the soil in two forms – one is immediately plant available (inorganic), and the other (organic) is tied-up in a variety forms (i.e. in organic matter, microbial organisms, plant and root residues, etc.).
8. Soil pH and nutrient availability:  Soil acidity affects many soil processes, including microbial activity and the availability of nutrients to crops.
9. Phosphorus Saturation Index: Phosphorus is a relatively immobile nutrient within the soil and can be inaccessible to the crop unless it is in a form available for plant uptake. Factors that affect phosphorus plant uptake include organic matter content, fertilizer placement, and pH.
10. C:N Ratio: Soil microbes decompose organic materials in search of nutrients and energy sources. The relative amounts of energy (C) and nutrients (N, P, S) will determine whether decomposition will result in removal (immobilization) or release of nutrients (mineralization).

Check out Soil First Farming at: https://soilfirstfarming.ca

Information from: https://www.princeedwardisland.ca/en/information/agriculture-and-land/pei-soil-health-test-how-interpret-your-results 

Changes in soil organic matter over 18 yr in Prince Edward Island, Canada