Knowledge of soil health: NRCS has developed 17 indicators for soil quality
Soil health: it's the latest buzzword steamrolling its way through agriculture. While soil scientist Anthony Bly understands attraction to new fads, he hopes interest in soil health doesn't fall by the wayside. "So many things come and go, and th...
Soil health: it's the latest buzzword steamrolling its way through agriculture.
While soil scientist Anthony Bly understands attraction to new fads, he hopes interest in soil health doesn't fall by the wayside.
"So many things come and go, and this one doesn't need to go," Bly said. "The reason why it's so important and why it can't die is that societies are built on their resources. Food resources are a huge part of that. Without a good soil resource, that falls apart."
Soil health is a term that's often used but not understood. The concept stems back to a basic knowledge of the soil. Bly describes soil as a dynamic body that incorporates biology, chemistry and physics in its role of supporting life. The Natural Resource Conservation Service has developed 17 indicators for soil quality that revolve around carbon, water filtration, nutrient cycling and soil structure. All of these factors are negatively impacted when tillage is introduced into the system.
"It's all about producing food, and it comes from the soil," Bly said. "Soil is not a medium. It has to be maintained and taken care of. The trend lately has been towards depletion."
Dwayne Beck manages an extensive no-till operation at the Dakota Lakes research station near Pierre and has invested his career into creating agricultural systems that rebuild organic matter in the soil.
"The way we do agriculture is a mining system," Beck said. "Long-term we can't do what we've been doing."
Beck believes that healthy soils can't be built on tillage practices. In order to retain the natural cycling of the soil's nutrients and imitate the native environment, his focus has shifted to reintroducing biodiversity into a no-till landscape.
"The biggest challenge is to mimic the natural ecosystem processes, such as the water cycle, mineral cycles and energy cycles," Beck said. "In farming we've forgotten that."
Beck's goal at Dakota Lakes is to replicate the biodiversity originally seen in the prairie. Through no-till, diversified rotations and cover crops, he has developed a versatile system to retain nutrients in the soil and build up organic matter. Beck is also beginning to experiment with integrating livestock back onto crop ground. All of these practices are strategies to prevent soil erosion and plant material from leaving the land.
"Ecosystems aren't designed to leak," Beck said. "They're designed to cycle. The ultimate goal has to be eventually to close the loop on the cycle of nutrients entering and leaving."
Al Miron farms about 1,500 acres with a neighbor near Crooks using no-till. Miron, an animal nutritionist and consultant, started farming in 1972 using conventional farming methods.
"I was a part of that at that time," Miron said. "We were doing extensive tillage. I could see what was happening to the soil even at that time."
Miron's concerns with wind and water erosion motivated him to transition to no-tilling in 1988. Despite the dry conditions, Miron's yields turned out better than the national average.
"I basically never looked back after that with respect to no-till," Miron said.
Since switching to no-till, Miron has seen an increase in soil organic matter. Soil tests dating back to 1975 showed an average of 2.5 percent organic matter on his property, with some tests reading as low as 0.7 percent on eroded hillsides. Now Miron's soil samples are averaging 4.5 percent.
Miron has discovered that the amount of organic matter in his soil impacts water retention. A 1 percent increase in organic matter increases the soil's ability to retain 0.5 to 1 inch of additional rainfall and also sequesters additional carbon and nitrogen in the soil. Tillage does the opposite, with each pass leading to a loss of approximately half an inch of moisture.
The biological activity within Miron's soils has also increased since his switch to no-till. Earthworms and microbial activity enhance the soil's ability to filtrate water and cycle nutrients more efficiently. A faster infiltration rate has reduced erosion on Miron's land.
"Tillage destroys macropores and fills up those pores," Miron said. "If those pores are sealed off, they can't absorb water."
Though a common misconception is that no-till results in a weed patch for a field, Miron has learned that with proper management, weeds are no more a problem than they are with tillage. The weeds he controls have changed, but Miron combats this with appropriate herbicides and timing of his applications.
"I don't feel I use any more herbicides now than I did when I was doing tillage," Miron said.
While Miron has successfully implemented no-till practices and is now experimenting with cover crops in his never-ending quest to improve his soil, some farmers are still skeptical of the benefits of no-till, especially in areas that are already wet. But with the technology that is available to control water in the soils, Bly has seen successful farmers increase organic matter in their soils using no-till even in wet conditions.
"It's a mind shift," Bly said. "You have to be somewhat educated and do your homework and understand that it has its challenges like tillage farming."
Bly admits that farmers closing in on retirement age are less willing to change to no-till. Rebuilding soil health is a slow process requiring several years to see marked improvement, but it isn't only about impacting tomorrow. It's about thinking ahead to future generations. Bly believes the key to improving the momentum of soil health lies in investing in younger farmers.
"There will be a tipping point someday," Bly said. "If we continue to look at crop production on an annual basis without looking at soil maintenance costs, which is soil health, someone's going to pay for that in the end."