When you test more than 200,000 soil samples in a year, you not only learn something about how Arkansans grow crops, gardens and lawns, but also the value of recommendations that result from soil test results.

Each year, the Arkansas Agricultural Experiment Station publishes the Wayne E. Sabbe Arkansas Soil Fertility Studies. The latest edition, released in spring, features 12 research reports prepared by scientists with the U of A System Division of Agriculture and the Dale Bumpers College of Agricultural, Food and Life Sciences at the U of A.

This edition includes investigations into the effects of fertilization on row crops, blackberries, forage and soil; plant tissue nutrient testing; and perceptions of stakeholders when it comes to the state's public soil testing program.

Each year, the feature article summarizes the chemical properties of soil samples to the Arkansas Soil Testing Program. In 2023, Arkansas clients submitted a record of 201,896 soil samples — representing approximately 1.5 million acres of land — to the experiment station's Marianna Soil Test Lab. The article found that row crop use accounted for 74% of sampled acreage; hay and pasture uses accounted for 15%, and home lawns and gardens accounted for 2.3%. Mississippi County submitted the most samples, with 26,953; Clay was next at 23,141, and Poinsett County was third, with 22,669 samples.

A study led by Aurelie Poncet, assistant professor with the Crop, Soil and Environmental Sciences Department, found that 81% of those who submitted samples to the soil test lab used lime and fertilizer recommendations from the Division of Agriculture to improve soil fertility.

"We have a very comprehensive record each year about the status of soil fertility across the state of Arkansas," said Nathan Slaton, who edited the publication and serves as associate vice president for agriculture and assistant director of the experiment station.

Slaton noted how the publication's reports are of interest to a variety of stakeholders, from horticulturists to rice producers, reflecting the widely applicable nature of the work.

The online publication sees hundreds of downloads from across the United States — and the world — Slaton said. Ultimately, the publication helps university researchers validate or develop new fertilizer and soil nutrient management recommendations.

"It's important that as production systems change and new genetics are released into the hands of farmers … that soil fertility data that evaluates the reliability of soil test information is checked over time," Slaton said.

The 2024 Arkansas Soil Fertility Studies include:

• Arkansas soil-test summary for samples collected in 2023
• Sulfate runoff dynamics from edge-of-field losses at selected Arkansas Discovery Farms
• Potassium fertilization effects on cotton yield and tissue-K concentration in Arkansas
• Assessment of potassium loss by runoff in different cotton production systems
• Bermudagrass forage yield and soil test response to phosphorus and potassium fertilization
• Verifying nitrogen rate recommendations for blackberry grown in Arkansas
• Effectiveness of in-season potassium fertilization on irrigated corn production
• NUMBERS: Nutrient management database for effective rate selection
• Assessing producers' engagement with the services provided by the Marianna Soil Test Laboratory
• Updated profit-maximizing potash fertilizer recommendations for corn
• Cotton response to nitrogen on silt loam soils: year two results
• Cover crop and phosphorus and potassium application rate effects on soil-test values and cotton yield

LEADING FREE SOIL TESTING

All Arkansans can submit soil for free testing thanks to the Arkansas Fertilizer Tonnage Fee Program. Fertilizer tonnage fees are used to support routine soil testing services, soil fertility research and the regulation and enforcement of fertilizer-related laws that benefit both farmers and the broader public.

Residents can submit soil samples to an Arkansas Cooperative Extension Service county office, which will then forward them to the Marianna lab. These extension offices are located in each of Arkansas' 75 counties. The extension service is the outreach arm of the Division of Agriculture.

The lab's routine analysis sheds light on soil pH and nutrient availability for selected nutrients, providing recommendations to achieve optimal soil fertility based on crop. The testing is used by individuals from golf course superintendents and farmers to home gardeners and landscapers.

Poncet's study assessed producers' use and satisfaction when it comes to the Marianna lab. Researchers collected 98 responses that were considered representative of Arkansas producers' practices.

Responses revealed that most of the state's producers collect soil samples to inform their management practices and use the free soil testing services provided by Marianna lab. Overall, most Arkansas producers are satisfied with the lab and its services.

The Marianna lab, which is the second-largest public soil testing program in the United States, accounts for 80% to 85% of the analysis for all of the samples collected in Arkansas, according to Slaton.

To learn more about the Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website. Follow us on X at @ArkAgResearch, subscribe to the Food, Farms and Forests podcast and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. Follow us on X at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.

---

About the Division of Agriculture: The University of Arkansas System Division of Agriculture's mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation's historic land grant education system. The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three system campuses. Pursuant to 7 CFR § 15.3, the University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.