We will soon be leaving 2015 behind us. As a reminder, 2015 has been the International Year of Soil. It is a tribute to our greatest natural resource that provides most of the food we eat.
I believe the next decade will be dedicated to building soil health to improve that national resource. To ensure that, on December 3, 2015 the Soil Health Institute (SHI) was launched. The SHI is an association dedicated to protecting the health of this important resource. It will bring stakeholders together to have a dialogue, lead the direction of research, foster education and communications and work to lessen the impact of policy on soil health.
To learn more about the Institute and its activities, read the press release.
We should all care about the soil as it provides more than 95% of our food. Soil also provides an essential life-sustaining role in cleaning air and water, storing water and carbon, and recycling carbon and nutrients to support biological life. While farmers are good stewards of the land—we are not going back to the dust bowl days—we are losing acres of arable lands. The acres that are farmed aren’t healthy, and today’s commercial farming techniques don’t necessarily promote soil health either.
When we lose our soil, we upset the balance of nature. It has been estimated that over 40% of the soil used for agriculture globally is degraded, and that half of the earth’s topsoil has been lost during the last 150 years. Soil degradation is the slow decline in land quality caused by human activity along with some impact from extreme weather events. Unfortunately soils degrade and are lost faster than nature’s ability to remediate or replenish this natural resource.
There are many ways soils are degraded—from compaction, repeat flooding, lack of drainage, burning off organic matter, acid pH, sodium or salinity buildup, leaching of essential nutrients, soil loss due to erosion, etc. Soil degradation speeds up soil erosion and reduces soil productivity. Think back to the dust bowl and the era of the plow when top soil was lost at a dramatic rate. It took decades of conservation and stewardship to replace that topsoil and return fields to productivity.
The slow process of restoring degraded soils begins by eliminating practices that degrade soil, protecting the soil from erosive forces, the appropriate addition of crop nutrients and lime, building organic matter levels, maintaining soil pH and EC (electroconductivity) in optimal ranges, widening cropping rotations, reducing or eliminating tillage and adding cover crops to build health.
Restoring soils and building soil health requires the right balance of nutrients. Recent studies show that proper fertilizer use maintains or improves soil microbial activity, boosts inputs of crop residue returned to the soil, and can maintain soil organic matter—all while enhancing crop yields. Crops, worms, soil insects and microbes need a balanced diet of nutrients.
One of the most important things you can do to build soil is build carbon. Sources are great sinks for carbon and great storage lockers as well. One of the elements of a high quality soil is organic matter at 3% or greater. Of course carbon comes in two forms, active or passive. Most of the carbon in the soil is passive, but you need a certain amount of active carbon to feed the microbes. Green plants with active root systems are the major source of this carbon that feed microbes. That is why they say “roots in the ground all year round.”
The damaging effects of soil degradation are felt on and off the farm. Streams and lakes become clogged with sediment and nutrients lost from agricultural fields, creating hypoxia zones that damage aquatic life due to oxygen depletion.
As 2015 wraps up and we end our tribute to soil as a natural resource, let’s refocus our efforts—to improve the health of our soils over which we have stewardship.
Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at firstname.lastname@example.org or leave a comment below.