In this episode, we talked to Shawn Nield, Idaho’s state soil scientist. State soil scientists are employed by the National Resource Conservation Service, or NRCS, a department of the USDA. Their job is to research and manage soil through data collection, consultations with farmers and landowners, and planning or inspecting building projects.
We started our interview by asking Nield, what exactly is healthy soil? He defined soil health as the ability to provide nutrients, and said that healthy soil has a whole living ecosystem under the ground.
Now that we know what it means for soil to be healthy, how healthy is Idaho’s soil? Nield explained that the situation in the 80’s was bad due to soil erosion and we’ve improved a lot since then. That said, our soil quality in Idaho still isn’t great. He stated that the unhealthy looking soil is barren soil, like the soil we see in fields in the winter which are most times left uncovered and exposed to soil and water erosion.
After that answer, Nield spoke to how Idahoans, specifically farmers, can help improve Idaho’s soil quality. There are four basic principles of soil health:
- Keep the ground covered to protect the topsoil
- Keep a live root in the ground to provide nutrients
- Minimize disturbance by reducing tilling
- Employ diversity
This is great advice, but have we seen the principles of keeping ground covered, keeping a root in the ground, reducing tilling, and incorporating diversity applied on a large, commercial scale? And if so, have they been financially successful?
Nield argues yes and gives an example using strip till sugar beet farming. Strip-tilling refers to the practice of tilling narrow rows with undisturbed areas in between crops. The strip-till sugar beets have shown higher sugar content than conventional till beats. Research that came out of southern Idaho has shown that industrial strip tilling can be done successfully.
Switching gears, another aspect of soil health is fertilization. We’ve heard negative things about nitrogen fertilizers specifically. According to the Cary Institute of Ecosystem Studies, “When nitrogen fertilizer is applied faster than plants can use it, soil bacteria convert it to nitrate. Water-soluble nitrate is flushed out of soils in runoff, where it pollutes groundwater, streams, estuaries, and coastal oceans. In farming communities, it’s not uncommon for nitrate to render drinking wells unusable.”
We then asked Nield how people can reduce their dependence on nitrogen fertilizers. Some farmers have been using legumes as cover crops, which deliver nitrogen from the atmosphere back into the soil. Some farmers have completely stopped using nitrate fertilizer anymore, and take issue with using nitrates which shock the system of plants and become water soluble. That advice combines the principles of keeping a root in the ground, covering the soil, and increasing diversity with a way to decrease nitrates and maintain water quality.
Finally, we asked about resources for those who want to learn more or are seeking agricultural and soil advice. Nield recommended that any land owner with an agricultural commodity contact an NRCS field office to start a conversation about soil health. Remember, NRCS is the Natural Resource Conservation Service, and their website contains plenty of information and resources for those curious about sustainable farming. We will continue our discussion on soil science and sustainable agriculture on next week's episode of Sustainable Idaho.
Sources and More Info:
Cary Institute on Nitrogen Fertilizers
https://www.caryinstitute.org/news-insights/podcast/downside-nitrogen-fertilizer
NRCS Idaho Webpage
