Soil: Keep it Growing, Not Blowing

The past week brought some typically spring-like weather in southwest Montana.  We went from rain and then snow earlier in the week, to 70 degrees and calm to start off the weekend.  Then our old friend wind made it’s appearance on Saturday, blowing a gale that wreaked a fair amount of havoc.  We all can list off the things that we saw around the area, but we’ve been hearing a lot of talk about the amount of soil that took to the wind during this time.

While we all hoped that the precipitation that we received earlier in the week would have prevented the losses that went with the gale force wind, it’s apparent that this was not the case.  It only takes a little rainfall and snowfall accumulation research to see that the conditions that we have had since fall of last year have set us up for the dry conditions that we are seeing today.  The ground is “talc dry”, as one local producer termed last week, describing how a fence post hole showed no moisture in the upper 18 inches of soil.  Combine that with any sort of disturbance, and pretty soon the most important part of a piece of ground is blowing into the next county.

These dustbowl-like sights are a good reminder to discuss concepts that the Natural Resource Conservation Service has been promoting nation-wide for a number of years.  The following Soil Health Management Tips from the NRCS website cover the basics of how to hold on to your soil resource, and improve your operation as a whole at the same time.

Crop residue management improves soil health

Soil works for you, if you work for the soil.  By using management practices that improve soil health, you will see increased productivity and profitability immediately and into the future. A fully functioning soil produces the maximum amount of products at the least cost. Soil will not work for you if you abuse it.

Managing for soil health (improved soil function) is mostly a matter of maintaining suitable habitat for the myriad of creatures that live in the soil. This can be accomplished by disturbing the soil as little as possible, growing as many different species of plants as practical, keeping living plants in the soil as often as possible, and keeping the soil covered all the time.

Manage More by Disturbing Soil Less

Soil disturbance can be the result of physical, chemical or biological activities. Physical soil disturbance, such as tillage, results in bare and/or compacted soil that is destructive and disruptive to soil microbes, and it creates a hostile environment for them to live. Misapplication of farm inputs can disrupt the symbiotic relationships between fungi, other microorganisms, and plant roots. Overgrazing, a form of biological disturbance, reduces root mass, increases runoff, and increases soil temperature. All forms of soil disturbance diminish habitat for soil microbes and result in a diminished soil food web.

Diversify Soil Biota with Plant Diversity

Plants use sunlight to convert carbon dioxide and water into carbohydrates that serve as the building blocks for roots, stems, leaves, and seeds. They also interact with specific soil microbes by releasing carbohydrates (sugars) through their roots into the soil to feed the microbes in exchange for nutrients and water. In order to achieve a high level of diversity, different plants must be grown. The key to improving soil health is ensuring that food and energy chains and webs consist of several types of plants or animals, not just one or two.

Biodiversity is ultimately the key to the success of any agricultural system. Lack of biodiversity severely limits the potential of any cropping system and increases disease and pest problems. A diverse and fully functioning soil food web provides for nutrient, energy, and water cycling that allows a soil to express its full potential. Increasing the diversity of a crop rotation and cover crops increases soil health and soil function,  reduces input costs, and increases profitability.

Keep a Living Root Growing Throughout the Year

Living plants maintain a rhizosphere, an area of concentrated microbial activity close to the root. The rhizosphere is the most active part of the soil ecosystem because it is where the most readily available food is, and where peak nutrient and water cycling occurs. Microbial food is exuded by plant roots to attract and feed microbes that provide nutrients (and other compounds) to the plant at the root-soil interface where the plants can take them up. Since living roots provide the easiest source of food for soil microbes, growing long-season crops or a cover crop following a short-season crop, feeds the foundation species of the soil food web as much as possible during the growing season.

Healthy soil is dependent upon how well the soil food web is fed. Providing plenty of easily accessible food to soil microbes helps them cycle nutrients that plants need to grow. Sugars from living plant roots, recently dead plant roots, crop residues, and soil organic matter all feed the many and varied members of the soil food web.

Keep the Soil Covered as Much as Possible

Soil cover conserves moisture, reduces temperature, intercepts raindrops (to reduce their destructive impact), suppresses weed growth, and provides habitat for members of the soil food web that spend at least some of their time above ground. This is true regardless of land use (cropland, hayland, pasture, or range). Keeping the soil covered while allowing crop residues to decompose (so their nutrients can be cycled back into the soil) can be a bit of a balancing act. Producers must give careful consideration to their crop rotation (including any cover crops) and residue management if they are to keep the soil covered and fed at the same time.

For questions on soil health practices that would work for your piece of ground, contact your local Conservation District or NRCS office.