No Till Notes: 'It's all about the carbon'

The common thread that ran throughout the no-till winter conferences I attended in the past month is carbon.

Adding carbon to the soil is critical to restoring health to the soil by increasing the organic matter content of the soil. Producers in today’s modern agricultural systems are working with soils that contain far less carbon than our soils originally contained prior to the implementation of modern agriculture. All of our soils are now degraded. The good news is we now know how we can regenerate our soils and put the carbon back in the soil. This is a very simple process, but also very difficult.

So why is carbon so important? Carbon is the building block for soil health. As you increase the carbon content of the soil, you begin to improve the aggregate stability of the soil. These aggregates are formed by excretions from the soil microbes which begin to stabilize the soil particles into larger aggregates. This provides the home for all the soil microbes living in these aggregates.

A healthy soil provides a healthy environment for these soil microbes. The microbes will provide the nutrient cycling of soil organic matter making nutrients available for the plants growing in the soil.

These aggregates also provide the pore space necessary to infiltrate and store water in the soil. In our semi-arid environment the ability to infiltrate and store water is critical to crop production. Stable aggregates that can infiltrate and store additional water can also lower our irrigation pumping requirements by making our soil’s more water efficient. Lowering our groundwater consumption is critical to stabilizing the rapid decline of our groundwater resource.

The carbon, nutrient and water cycles in a healthy soil are all interrelated. For these cycles to perform to the best of their abilities, the soil must contain all of the necessary ingredients. If the soil is lacking carbon the nutrient and water cycles are unable to perform to their highest abilities.

Unlike the other nutrients in the soil there isn’t a synthetic carbon that can be added to the soil. Producers can go to the local fertilizer dealers and purchase nitrogen, phosphorous, chloride, calcium, zinc and other nutrients found in the soil. You have to manage the soil and production practices to add carbon to the soil.

Management practices that can increase the amount of carbon in the soil include minimal soil disturbance and leaving crop residues on the soil surface. These management practices used in no-till crop production are the first step in improving soil carbon. These practices will improve soil carbon at a slow rate and reach a stabilized plateau in my opinion.

On our farm we have seen an increase of soil carbon in our twenty five years of no-till crop production. We have improved the carbon in the soil as our soil organic matter levels have increased slowly over time. I also feel we are still well below where are soil carbon levels need to be. No-till production practices are a step in the right direction, but if we are going to add more carbon to our soil we are going to have to change our production model.

I really believe that after all the years of no-till crop production we are still working with a degraded soil. Our soil is still not functioning at the level our soil is capable of. If we adopt management strategies to adding more carbon to the soil we work with I believe we can markedly improve the function and health of our soil.

Next week, I’ll look at some of the strategies I think we need to implement to improve the performance and health of the soil on our farm.