Dean Krehbiel is state resource conservationist for the Kansas Natural Resources Conservation Service.
What is soil health and how do we measure it?
The NRCS defines soil quality as “the capacity of a specific kind of soil to function as a vital living ecosystem, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation.” For people active in production agriculture, it may mean highly productive land, sustaining or enhancing productivity, maximizing profits, and/or maintaining the soil resource for future generations.
Soil is more than just dirt. It does several things, including:
• Regulates water. Soil helps control where rain, snowmelt and irrigation water goes. Water and dissolved solutes flow over the land or into and through the soil.
• Sustains plant and animal life. The diversity and productivity of living things depends on soil.
• Filters potential pollutants. Soil minerals and microbes are responsible for filtering, buffering, degrading, immobilizing, and detoxifying organic and inorganic materials, including industrial and municipal by-products, plus atmospheric deposits.
• Cycles nutrients. Carbon, nitrogen, phosphorus, and many other nutrients are stored, transformed, and cycled in the soil.
• Physical stability and support. Soil structure provides a medium for plant roots. Soils also provide support for human structures and protection for archeological treasures.
The six components of soil quality/soil health management:
Choosing specific practices within each component depends on the situation, since different types of soil respond differently to the same practice. Each combination of soil type and land use calls for a different set of practices to enhance soil quality.
1. Enhance organic matter: Whether soil is naturally high or low in organic matter, adding new organic matter every year is perhaps the most important way to improve and maintain soil quality.
2. Avoid excessive tillage: Reducing tillage minimizes the loss of organic matter and protects the soil surface with plant residue.
3. Manage pests and nutrients efficiently: An important function of soil is to buffer and detoxify chemicals, but soil’s capacity for detoxification is limited.
4. Prevent soil compaction: Compaction reduces the amount of air, water, and space available to roots and soil organisms. Compaction is caused by repeated traffic, heavy traffic, or traveling on wet soil.
5. Keep the ground covered: Bare soil is susceptible to wind and water erosion as well as drying and crusting. Ground cover protects soil, provides habitats for larger soil organisms (such as insects and earthworms) and can improve water availability.
6. Diversify cropping systems: Each plant contributes a unique root structure and type of residue to the soil. A diversity of soil organisms can help control pest populations and a diversity of cultural practices can reduce weed and disease pressures.
Soil is a living and life-giving natural resource.
By farming and ranching using sound soil health principles and systems, farmers and ranchers can increase their soil’s organic matter, sequester more carbon, increase water infiltration, improve water quality, and improve wildlife and pollinator habitat—all while harvesting better profits and often better yields.
Regardless of your farm and ranch objectives, the foundation for long-term food and fiber production and a healthy environment depends upon well cared-for and resilient soils.