By Madeline Vogel And Anna Cates
What are soil health management systems?
Soil health management systems are agricultural systems that prioritize the health of soils, by reducing soil disturbance and keeping living roots in the ground. Healthy soils should protect soil carbon and nutrients, capture and store water, and promote soil organisms. To promote healthy soil, we recommend:
- Armoring the soil
- Minimizing soil disturbance
- Increasing plant diversity
- Maintaining continual live plant/roots
- Integrating livestock
How can integrating soil health principles help farmers and the environment?
The first soil health principle, “soil armoring,” is all about keeping the ground covered as much as possible. For example, farmers can leave crop residues instead of tilling. The residue acts as a shield, protecting the soil from wind and water and reducing soil evaporation rates to keep moisture available for plant use. Ground cover reduces runoff, and nutrient loss, an economic savings to farmers. Residue and living plants provide habitat for beneficial microorganisms, which, along with bacteria and fungi, are responsible for organic nutrient cycling.
The second soil health principle is minimizing soil disturbance. Soil disturbance could be biological (e.g., overgrazing), chemical (e.g., over-application of fertilizer and pesticides) or physical (e.g., tillage). Minimizing soil disturbance allows natural soil structure to develop, with large pores to infiltrate rainwater and small pores to hold water during dry spells. Good soil structure also protects soil organic matter, an important component of crop productivity.
Plant diversity is another important component, mimicking the multifunctionality and resiliency of natural plant communities. Plant diversity can reduce pest and disease, pressure, leading to lower pesticide and herbicide use. It can also provide greater economic stability to the farmer, bringing in different crop markets and spreading out labor.
The fourth principle, incorporating a living root year-round, integrates the first three principles, but highlights the unique role of roots. Roots change soil biology and structure. Plants feed carbon to soil microbes, enhancing nutrient cycling at the root surface. In a cash-grain cropping system, cover crops are a good way to integrate these principles.
Another way of improving soil health is livestock integration, as livestock manure jump-starts soil biological activity. Economically, livestock provide an opportunity for farmers to grow more perennials and cover crops for forage. Livestock can be integrated on row crop land by allowing winter and fall grazing of cover crops and crop residues, and spring and summer grazing of annual and perennial plants.
How does soil health management change soil water behavior?
Farmers across Minnesota apply these principles in creative ways. A new research project in partnership with the Sand County Foundation and Farmers Edge aims to understand how the application of soil health principles changes soil water behavior. We’re monitoring soil water status and soil health indicators on 15 pairs of soil health-focused and conventional farms across Minnesota and Wisconsin from 2021-2022.
Farmers and researchers both have access to daily soil temperature and moisture data to 40 inches, which will help us understand how soil health management changes water movement through the profile. In addition, we’ll evaluate soil pore sizes and soil biological metrics. The farms include many soil types and cropping systems, contributing to the ongoing efforts at the Minnesota Office for Soil Health to compile a database of regional soil health metrics.
Stay tuned for research updates here and at UMN Extension events as we learn more about the interaction between soil health and water behavior.
Source : umn.edu