The Soil Health Institute (SHI) along with other scientific bodies, advocates four basic soil health principles that apply to all agricultural systems in one way or another. To maximize benefits through accelerated soil health improvements, they need to be implemented as a system. This creates a synergistic effect where the sum is greater than the individual parts.
In order to shift the needle, farmers need to look at soils differently. The definition below of soil health helps producers’ home in on what they need to do to accomplish this:
“Soil Health is the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans.”
This definition speaks to creating a management system that is sustainable and considers the soil microbes as a key component of the system that drives soil functions necessary for food and fiber production.
Farmers need to understand the role that soils play in agricultural production systems. The functions necessary to be successful are nutrient cycling, regulating water (infiltration and availability), filtering and buffering pollutants, physical stability to support agricultural activities (they must get across the field), and creating habitat for soil organisms beneficial for food and fiber production. All of these functions are impacted or mediated by soil microbes. Here at SHI, we like to think of farmers that they are habitat managers for soil microbes.
The four soil health principles are:
- Minimize soil disturbance – soil disturbance is any activity that impacts or destroys habitat for soil microbes. It can be broken into three categories: physical disturbance (tillage destroys the house microbes live in); chemical disturbance that impacts non-targeted organisms disrupting the soil food web, making them less resilient; and biological disturbance which includes the lack of diversity in crop rotations or overgrazing in grazing systems.
- Maximizing diversity – helps to create a balanced habitat for soil organisms, breaks pest and disease cycles, and provides diverse biomass both above and below ground that can be converted into soil organic matter. Diversity can be added by lengthening the crop rotation or adding perennials, planting cover crops after harvest, and incorporate livestock grazing through a strategy that ensures even distribution of manure while preventing overgrazing.
- Keep continuous living roots growing as much as possible – modern agricultural systems only capture solar energy for a portion of the year (100-120 days), while sunlight hits the earth year-round. Incorporating cover crops allows for plants to turn sunlight into food for soil microbes in the portions of the year commodity crops are not being grown. Plants feed soil microbes through exudates, hence the more exudates, the larger the microbial community that can be supported. In some parts of the country this can be done almost year-round, other parts not so much, but they still can provide benefits.
- Maintain residue cover as long as possible – residue cover controls erosion while protecting soil aggregates that are so important for water infiltration. Cover also keeps the soil cool during the heat of the summer. Bare soil temperatures can exceed 100 °F at a depth of 1” to 2”, which creates a hostile environment for soil microbes, residue cover can keep soil temperatures 15-20 °F cooler. This reduces evaporation while creating a favorable habitat.
There are basically five or six conservation practices or activities that farmers can leverage to develop a soil health management system. These include:
- Conservation Tillage – preferably no-till, but some crops require tillage to harvest, limiting the depth and area tillage is done can be useful
- Cover Crops – can be used to add diversity to a crop rotation with one or two commodity crops, e.g. corn-soybean, cotton-cotton-peanuts. They need to be selected with a purpose, a cover crop should benefit the crop that will follow it. Cover crops should be planted as a mix, multi-species mixes promote more diversity.
- Conservation crop rotation – rotation need to move away from monocultures or continuous commodity production, e.g. continuous corn or cotton
- Nutrient management – a nutrient management plan should be developed that considers the biological nutrient cycles occurring in the soil
- Pest management – pest management strategies need to consider beneficial organisms and how they will be affected
The science has proven that a well-executed soil health management system is key to a more sustainable future for agriculture and the planet. The benefits are numerous and the on-farm economics in the long-term make it a viable practice to pursue:
- Soil health systems build in resiliency against extreme weather events and droughts, reducing soil erosion and nutrient run-off in flooding and maintaining soil water during extended dry spells.
- This resiliency smooths out volatility with yields, allowing for more consistent and predictable results.
- Input costs such as irrigation, fertilizers, and pesticides are reduced through the adoption of soil health practices that can positively impact margins and therefore profits.
- Sequestering more organic carbon in the soil means that crops and the soil biome can thrive. Less CO2 is also released into the atmosphere and helps mitigate climate change.
We can’t over emphasis the importance to develop and implement a soil health management system and the benefits it brings. While improvements can be made by introducing one activity at a time, to truly see changes requires a synergistic approach. It may take three to five years for a producer to notice a measurable benefit through adopting soil health management systems, but the proven results should convince a producer to stay with implementing the system.