Common Soil Health Improvement Methods and their Financial Benefits
Soil health is a widely talked about issue that often leads to more questions than answers. What exactly is soil health? Do we all define it the same way? How do we know when soil is healthy? Do we need to constantly be improving soil health or is there a threshold we can reach where soil will maintain its own "health"?
To start, let's define soil health: "The ability of soil to support crop growth without becoming degraded or otherwise hurting the environment."
As soil becomes degraded, growers become more reliant on nutrition inputs to build fertility back into the soil. If plants cannot reliably use all of the added nutrients, those nutrients can leach out from the soil and either run off into waterways or seep into groundwater.
In Ontario, our soil is at risk from several threats, including but not limited to: an increased demand on food production with continuously shrinking amounts of farm land, increased frequency of extreme weather, and changes in cropping practices that can reduce soil health. There are several trends that have also led to reduced soil health in Ontario. This includes a major shift to more annual crops, the use of less diverse crop rotations, a reduction of hay and manure availability, and the use of increasingly larger and heavier equipment.
There are three main soil improvement actions we are going to focus on in this article:
Building soil organic matter
Diversifying crops
Minimizing soil disturbance
Keeping living roots all year
Building Soil Organic Matter
Soil organic matter (SOM) consists of plant and animal material at various stages of decomposition that soil microbes can metabolize and use to synthesize new substances. SOM gives a range of benefits to both the physical and chemical properties of soil and can provide regulatory ecosystem services. SOM also acts as a major sink and source of soil carbon, which is the driving force of the movement of energy in soil.
A common way of increasing SOM is through applications of compost or manure. These amendments help to improve SOM as they provide fuel for microorganisms, and help to improvement soil structure and aggregate stability. Additionally, improved SOM can increase water holding capacity as organic matter can hold up to 10 times its weight in water. By storing more water in the soil and improving soil structure, crops will start to become more resilient in the face of extreme weather.
Droughts may not have as big a detriment to your crop as there is more available water for plants to access. Extreme rain events may not be as destructive to the top soil as improved soil structure will allow more water to infiltrate into the soil horizon and increased SOM will absorb more stormwater. Increased water holding capacity would lead to a reduction in money spent on water usage. Fewer crop losses due to extreme weather leads to more earnings from harvest.