Managing Soil Structure and Quality Biological Management Practices to Maximize Soil Quality
By DR. KARL WYANT | Vice President of Ag Science, Heliae Agriculture Board of Directors, Western Region Certified Crop Advisers
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anagement practices that improve soil health and soil quality have gained considerable attention over the past few years. If you are wondering how to get started and what to focus on, you have come to the right place! In Part 2 of this article series, I focus on how the living, biologic components of the soil, the microbes, directly impact your soil, including the structure (e.g., aggregation and pore space). My focus on bacteria and fungi in the soil is a perfect complement to Part 1 of this article series, where we explored the physical and chemical components behind soil structure. Part 1 can be found in the January/February 2021 edition of Progressive Crop Consultant.
Figure 1. Holistic soil management can be used to help improve soil structure and soil quality. We explored the physical and chemical controls in Part 1 and explore the biological controls in Part 2 of this article series (all figures and tables courtesy K. Wyant.)
Let us kick things off with a quick reminder of some terminology and drive home the connection between soil quality (structure) and soil health (biology). Soil quality: This term has broad application on your farm. Soil quality refers to how well a soil functions physically, chemically and biologically and does its “job” (Figure 1). Many factors influence the soil quality on a farm and are summed up in Figure 2. In this article, we will focus on the biological management practices that maximize soil quality, expressed here as soil structure. Soil health: This term refers to the interaction between organisms and their environment in a soil ecosystem and the properties provided by such 22
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interactions. When you think of soil health, think of the biological integrity of your field (e.g., microbial population and diversity) and how the soil biology supports plant growth. There is a direct link between soil health (the living component) and soil quality (the structural component). The linkage is fungi and bacteria in the soil and the byproducts they secrete. These byproducts help restore your soil structure (Figure 3, see page 23). Furthermore, well-structured soils are characterized by excellent soil health, which indicates a feedback loop between the soil biology and soil particles. But how exactly do the microbes put your soil back together?
May / June 2021
Figure 2. Crop productivity is influenced by several interrelated concepts, which have an impact on the soil quality of a field.