Photo by Tim McCabe, USDA NRCS
Building soil health on range, pasture, hay or cropland is about 4 principles:
- Minimize disturbance of the soil
- Maximize diversity of plants in rotation
- Keep living roots in the soil as much as possible
- Keep the soil covered with plants and plant residues
Step one in the process of cutting your operating expenses without sacrificing productivity is understanding soil health, according to Ray Archuleta. Archuleta, from the NRCS East National Technology Support Center in North Carolina, spoke to a full house on soil health at the Montana Association of Conservation Districts (MACD) convention in November. He explained that a healthy soil is one that is able to hold together and yet transmit water effectively. He did two vivid demonstrations that showed the importance of this - the slake and infiltration tests. In the tests he compared soils that have been cover cropped with samples of identical soil types that have been conventionally cropped. Watch him demonstrate these tests by following this link to his U-tube video.
Soil that was no-tilled and had a diverse rotation held together and infiltrated water at a much faster rate than soil that was continuously tilled. The conventionally tilled soil fell apart in water, and when water was applied to simulate precipitation, it ponded on top and infiltrated very slowly. That situation could lead to more runoff. Ray commented that if we fix our soil, flooding could be reduced (as well as pesticide and nutrient runoff). This is because when the soil is healthy the water cycle functions – allowing water to infiltrate instead of running off and leading to erosion or the flooding we saw this season in parts of Montana. Ray challenged people to be connected to their land by seeing what is actually going on in their soil – get your hands in your soil and count earthworms!
After Ray’s talk, Mark Henning, Area Agronomist for NRCS in Miles City, talked about how to use cover crop mixes (called “cocktails”) as a tool to build soil health, and reviewed some examples of producers who used cover crop mixes this year to address resource concerns on their land. Cover crop mixes are fundamentally about feeding the soil biology (fungi, bacteria, nematodes, protozoa, earthworms and microarthropods) that “drive” the soil to function – making nutrients available to plants, infiltrating and storing water and producing a healthy crop. By having a living root in the ground more days out of the year, soil microbes (or the “micro-herd”) have more and better food sources. If you feed the micro-herd then they will feed your crop.
Mark gave an example of a producer in ND who got 62 bu/ac dryland spring wheat without any chemical fertilizer (the county average is 35 bu). The producer did this through no-till, a diverse cash crop rotation, cover crop mixes and using animals to mob graze cover crop mixes. He also showed pictures of two adjacent pastures from drought stricken Texas this year. The conventional field was almost bare of vegetation and the production on the cover cropped field was very good. He showed many examples of farmers that had switched over to this style of cover cropping, reducing or eliminating fertilizer and pesticides without sacrificing a bit of productivity.
The individual plants in these ”cocktail” mixes are chosen to complement the goal for your crop land (examples include providing armor, increasing organic content, breaking up a hardpan). Designing the mix is important, and should include a minimum of 8 different species in order to achieve a functional diversity of plants (legume, broad-leaved, etc.) and balance the carbon/nitrogen ratio. A different cocktail would be planted depending on what came before or would follow, the exact crop being planted, herbicide carryover and other considerations. Mixes can be broadcast into a standing crop, turned under or rolled and drilled. For pasture land, Archuleta recommends take half and leave half, or feed the herd and then feed the micro-herd. For more info on Ray’s soil health concepts, watch his 1-hour long video by clicking http://vimeo.com/channels/raythesoilguy
-adapted from an article by Carol Watts, Custer County Conservation District