To kick off the first call of ICCON’s Probing Into Soil Health Tests: Which Test is Best? series, ICCON hosted Dr. Patrick Freeze from Ward Laboratories, Inc. to delve into the intricacies of the Haney Soil Health Test. While soil health testing is a relatively novel concept for many farmers and agricultural professionals, there’s a growing interest in understanding its applications and how it can inform management decisions.
The history of the Haney test spans approximately 15 years. Dr. Rick Haney developed this test to examine soil as a holistic system, considering its physical, chemical, and biological components. Unlike standard soil tests, the Haney test places a significant emphasis on biological factors. The primary focus areas include fertility (H3A extract), microbial activity (24hr CO2), microbial activity (Water exchangeable organic carbon, WEOC), and mineralization (water extractable nitrogen).
The H3A extractant, named after the researchers who developed it, consists of citric, oxalic, and malic acids along with water. This combination mimics the acids produced by plant roots and is crucial in understanding soil dynamics.
The 24-hour CO2 respiration test gauges the soil’s potential for microbial activity. Enhanced microbial activity leads to better CO2 respiration, indicating improved soil capacity to support crop growth. The carbon and nitrogen components of the test assess organic carbon and total nitrogen levels concerning microbial capacity. The C:N ratio, a vital aspect of nutrient cycling, influences nitrogen immobilization and microbial carbon sourcing.
The primary focus areas of the Haney test include fertility (H3A extract), microbial activity (24hr CO2), microbial activity (Water exchangeable organic carbon, WEOC), and mineralization (water extractable nitrogen).
Utilizing the Haney test for fertilizer recommendations involves some uncertainty. It’s essential to note that there isn’t a direct correlation between fertility levels indicated by the Haney test and those from standard Bray or Mehlich extractions due to the passive nature of the H3A extractant. Results from the test show variability in higher pH soils, mainly due to carbonates consuming the weak acids of the H3A extractant.
Dr. Freeze highlighted the test’s usefulness in comparing different management systems or transitions, such as shifting from conventional tillage to no-till. It proves benefits to tracking changes over time, aiding farmers in understanding the impact of their management practices on soil function. Additionally, the Haney test is a valuable tool for troubleshooting agronomic issues and providing insights into soil function parameters often overlooked in standard diagnostic protocols.
Dr. Freeze highlighted the test’s usefulness in comparing different management systems, tracking progression over time, and emphasized that testing best takes place pre-planting in the Spring to avoid frozen ground.
Dr. Freeze recommends conducting the Haney Soil Health Test in the spring before planting when microbial communities are active, with a minimum soil temperature of 50 degrees Fahrenheit sustained for a few weeks. It’s also important to account for inherent soil type variability within a field while sampling. Typically, one Haney test sample can represent about 20 acres, but adjustments can be made accordingly.
Dr. Freeze’s full presentation can be viewed on ISAP’s YouTube channel. During the March call, ICCON will continue the three-part series, “Probing Into Soil Health Tests: Which Test is Best?” by discussing the Cornell Lab soil health test. Register for upcoming ICCON call here. If you are interested in joining the Illinois Cover Crop On-Farm Network to learn about new research and hear from cover crop specialists across the Midwest, please join our google group by sending an email to hvanbeck@farmland.org.
