By Chris Wolfenbarger, NRCS Soil Conservationist
The subject of soil health has been well discussed in the agriculture community for several decades. Practices such as no-till, cover crops and crop rotation have been a subject of coffee shop debates for as long as I can remember. Lately, the emphasis on soil health educational campaigns from some private institutions, as well as government, have largely focused on the biological aspects of soil health. However, as a field of study, soil health spans many scientific disciplines.
From geology, we learn how rocks and minerals are broken down by natural forces to form the inorganic portion of soil. Hydrology tells us where a rain might deposit sediments, while biology attempts to describe all the various organisms in or on the soil whose interactions comprise the food web. Chemistry helps us understand the processes and transformations that occur at a molecular level in the soil, which ultimately provides usable nutrients for plants. There are many other specialized fields of study that have a bearing on soil health. Combining knowledge from many disciplines to gain a clear picture of what a healthy soil looks like is a relatively new approach.
We can trace the beginnings of the modern concept of soil health to as early as 1881 when Charles Darwin released his last book, which detailed his ideas and observations of earthworms and how they affect soil formation. However, it wasn’t until the 1980s that soil scientists really started to look at biological activity in the soil as a major contributor to how soils are formed.
Traditionally, soil science has centered on more non-organic, geologic aspects of soil. Modern soil science research combines classic science with newer concepts of ecology to form new hypotheses about biological soil formation. Soil research around the world has sought to answer questions about the responses that soil organisms have to all types of cropping systems.
Some recent soil health research has looked at how a fully functioning soil can help with the nutrient budget. For instance, leaving crop residues has been shown to be a helpful addition to integrated pest management systems.
Combining precision agriculture with new soil management techniques has the potential to allow us to take advantage of natural soil processes. A pound of nitrogen (N) produced by an active, healthy soil may be worth more than a pound of synthetic N fertilizer that has to be transported and applied to the farm. Therefore, nutrients provided by healthy soils become more valuable.
Conservation practices that promote soil health have benefits beyond the obvious, and many tried and true practices can improve soil health. Terraces and grassed waterways allow us to manage moisture more effectively, as well as conserve soil. Crop rotation helps put residue in the soil and break pest lifecycles. No-till and cover crops can replace soil organic matter at an accelerated rate while preventing wind and water erosion. All these practices have the added benefit to society of contributing to cleaner improved water quality.
As times change, it is important to use every tool at our disposal to make sure we meet the food and fiber demand of a growing world population. Integrating new concepts of soil science with traditional high input farming has the potential to improve the quality of our soils.
For more information about soil health and conservation please contact your local Natural Resources Conservation Service field office by visiting tx.nrcs.usda.gov. You can also visit the NRCS soil health website at: http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/soils/health/.