Soil expert: Livestock help dirt
for Tri-State Livestock News
Getting healthy is all the rage these days, and don’t forget, your soil wants in on the action.
“From a young age I knew I wanted to follow in my father’s footsteps and become a soil conservationist,” began Kent Vlieger, guest speaker at the South Dakota Women in Ag conference held October 10-11 at The Lodge in Deadwood.
He persisted in that endeavor and is currently a Soil Health Specialist with the USDA Natural Resources Conservation Service in Huron.
“I am very passionate about agriculture and everything to do with it,” Vlieger continued. “My favorite aspect is working one-on-one with producers.”
He had attendees gather around a table where two demonstrations were set up. One was a rainfall simulation, and the other is known as a slake test. Each demonstration used two different soil samples which were taken from two different farming operations. The samples were collected only 50 feet apart. One producer utilized a corn and soybean crop rotation with tillage until the fall of the year and again in the spring before planting. The other operator utilized corn, soybeans, and wheat along with cover crops in rotation, plus livestock grazing later in the year. This soil had not been tilled for 20 years. Both samples were of the “houdek” type, which is the South Dakota state soil. It is a loam soil that works well in demonstrations.
Each sample had been placed in a slightly tilted container with receptacles below them to catch any runoff. Two cups of water (equivalent to an inch of rain) were poured all at once onto each. Almost immediately water began flowing into the receptacle for the tilled soil, while the other receptacle remained empty. After several minutes it was evident that the water in the first sample had been almost entirely lost to runoff, but had been completely absorbed by the second sample.
Next was the slake test, which featured two long plastic beakers filled with water. Vlieger dropped a sample of soil into each one. They were identical samples to those in the rainfall simulation exhibit, but these had been air dried. This demonstration tests the soil’s aggregate stability, or how well it holds together. Aggregates are soil particles and organic matter bound together with a biological ‘glue.’ These are what makes soils form clumps.
Attendees watched as the soil from the tilled field began to disintegrate and drop to the bottom of the beaker, while the second sample floated at the top of the water.
Vlieger explained that healthy soil is a living ecosystem in itself. It should be dark in color, moist, porous, and pliable. The color is due to organic matter content. Healthy, fully functioning soil provides an environment that sustains and nourishes plants, soil microbes, and beneficial insects.
“Rangeland soil loss can occur as well without proper management,” he stressed. “Overgrazing is usually the biggest problem, and this can lead to other issues such as water erosion and loss of organic matter.”
What can be done by operators to begin building and maintaining soil health? Vlieger outlined five conservation principles and ways to put them into practice. First, disturb the soil as little as possible. Use no-till techniques to plant and grow crops as opposed to plowing. Large scale no-till planters use rotating disk-like blades which slice through plant residue and cut small openings in the soil. Seeds are planted in these openings and then covered up. No-till drills can be leased if necessary.
The second principle is to keep the soil covered at all times. Applying or leaving plant residue on the surface reduces evaporation, helps protect the soil from erosion, and regulates soil temperature.
Increasing plant diversity is the third principle. Plant at least three crops in rotation, as well as cover crops when possible. Both of these practices used in tandem help to improve infiltration and nutrient cycling, reduce diseases and pests, and aid in weed suppression. Cover crops can include legumes, millets, oats, grasses, and even oilseed radishes.
The fourth principle is to keep a living root in the soil as long as possible. This is another instance where cover crops come into play. They are grown before, during, or after cash crops and not harvested as such, but their roots continue to feed soil microbes for as long as they remain alive in the ground.
Lastly, integrate livestock into the cropping system. Fall and winter grazing of cover crops can add nutrition at a time when forage quality may be low. Light to moderate grazing also stimulates plant growth.
“No one principle is more important than the others,” concluded Vlieger. “It may take time to realize the benefits of applying them, but in the long term it will certainly impact your bottom line.”
For more information go to: http://www.nrcs.usda.gov