The foundation of a healthy crop is balanced, healthy soil.
Producers in the Bluegrass and Crabapple Creek Watersheds in Audubon County gathered on June 30 to learn how they can evaluate their soil with a new testing method and improve it through reduced tillage and cover crops.
For many years, farmers have relied on traditional soil testing methods to identify a baseline of soil health, yet a new approach offers more information.
Theo Gunther, Iowa Soybean Association Environmental Programs and Services resource management specialist, explained the Haney Soil Test can supplement the standard soil tests with measures of microbial activity, plant available nutrients and microbial available water soluble carbon and nitrogen.
“One component of the Haney Test is an extraction solution that is intended to imitate root-soil interaction to determine nutrient availability,” Gunther said. “It is intended to provide a more accurate representation of what the root encounters in the soil.”
Additionally, this test provides a soil health score from 1 to 50 — the higher the better — based on microbial activity and proportions of microbial available carbon and nitrogen. The goal is to help guide farmers when adjusting management decisions focused on soil quality.
Soil health can be managed and improved by “minimizing soil disturbance, rotating crops for greater diversity, establishing living root growth year round and maintaining residue year round,” said Rick Bednarek, NRCS State Soil Scientist.
Focusing on these cornerstones, Bednarek and other experts discussed conservation practices that support these guidelines, including no-till and cover crops.
According to the speakers, no-till farming and cover crops help improve soil structure by transitioning soil from a “block” appearance to a “cottage cheese” appearance. This allows for better infiltration and reduced compaction in the field. Furthermore, these practices build microbial activity due to less soil disturbance and more food resources — roots and residue. Another benefit is increased organic matter, which not only improves the fertility of the soil, but also increases its water holding capacity.
While these practices go a long way toward improving soil health, the experts reminded the group that progress will take several years and results can be improved by implementing more than one practice. Bednarek said it takes seven to nine years in a good no-till system to see noticeable improvement, however, by stacking the practice with cover crops, producers may be able to cut that time in half.
“As producers reduce tillage, introduce cover crops and adopt additional conservation practices, they can evaluate the impact on their soil by conducting new soil tests,” Gunther said. “These, along with other measures of agronomic and environmental performance, will help evaluate the effects of adoption. There is still much to learn about the practical application of these evaluation methods.”