Planted over the winter months between cash crops, cover crops such as clover, oats and rye can mitigate soil erosion, improve soil health, water and nutrient retention, and provide weed and pest management options, according to research done by the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas System Division of Agriculture. Credit: U of A System Division of Agriculture

Using satellite imagery and government data, researchers measured a 5% increase in voluntary, or non-subsidized, cover crop adoption by Arkansas farmers.

The finding came out of research seeking to pinpoint how farmers were using cover crops and where, to help policymakers develop more targeted incentives for using cover crops.

Planted over the winter months between cash crops, cover crops such as clover, oats and rye can mitigate soil erosion, improve soil health, water and nutrient retention, and provide weed and pest management options, according to research done by the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas System Division of Agriculture.

Using data from 2013–2019, agricultural economists with the experiment station showed that cover crop adoption in Arkansas had the greatest association with a soybean-to-soybean cash crop rotation. This is no small thing: Soybeans are economically significant in Arkansas, accounting for $2.3 billion in cash farm receipts in 2023, according to the Arkansas Agriculture Profile.

Kris Brye is a University Professor of applied soil physics and pedology in the Department of Crop, Soil and Environmental Sciences for the University of Arkansas System Division of Agriculture. He is a co-author of a study publised in PLOS One showing a 5% increase in voluntary cover crop adoption by farmers in Arkansas with identification of associated cash crops. Credit: U of A System Division of Agriculture

Identifying the trends in what cash crops are grown with cover crops was "the real novelty of this study," said Lanier Nalley, corresponding author and head of the department of agricultural economics and agribusiness for the Division of Agriculture and the Dale Bumpers College of Agricultural, Food and Life Sciences.

"With GPS coordinates from the National Resource Conservation Service, we knew where cover crops were being grown for government payments, but the literature is very sparse, specifically in the South, about what crops are being rotated with cover crops," Nalley added.

The period from 2013 to 2019 was the latest available data at the time of the study, covering the entirety or parts of 27 Arkansas counties in the Arkansas Delta.

Merely estimating cover crop acreage would have been insufficient, Nalley explained, because it would give no insight into how cover crops fit into cropping rotations or their effectiveness.

Published in PLOS One under the title "Satellite Remote Sensing Reveals Voluntary Cover-Crop Adoption and Crop-Rotation Hotspots in the Mississippi Alluvial Plain," Nalley and his co-authors report that government support and voluntary planting tended to rise together, showing a positive relationship between the two.

The increase in voluntary cover crop adoption can be attributed to one of two things, Nalley said. It could be due to farmers who previously received government payments who decided to continue growing cover crops while avoiding the cumbersome record-keeping and application requirements for the government subsidies. Or it could be a "spillover effect," when farmers adopt the practice after seeing a neighboring farmer’s benefits of planting cover crops.

"An interesting thing for me was seeing how many people are just doing this because they realize the economic and environmental benefits and don’t even need government payments," Nalley said. "They are doing this for either profit maximization or land stewardship maximization."

Filling the gap

Despite expansion in federal funding for incentives to encourage farmers to adopt cover crops since 2012, Nalley said the growth in subsidized versus voluntary adoption of cover crops remained unknown due to challenges in obtaining ground-truthed spatial data and a reliable method for identifying voluntary adoption.

The lead author of the study was Zobaer Ahmed, Ph.D., when he was a senior research assistant at the University of Arkansas Center for Advanced Spatial Research. Ahmed is now the director of research and evaluation for the New York City mayor’s office.

Aaron Shew, a former assistant professor of agricultural economics with the Division of Agriculture, was a co-author of the study and is now the chief technology officer at Acres, a mapping and land analysis company.

"The initial push was finding out what cash crops were associated with cover crops," Nalley said. "But Zobaer is so good at this kind of work, I said, ‘Well, if we know how many acres of cover crops are in a county that are government-subsidized, let’s just find out how many total acres of cover crops are in a county, and the difference would be those people who aren’t getting government payments for it.’"

Subsidized vs. voluntary

Both government-supported and voluntarily planted cover crops became common in the study region over time. NRCS data showed government-funded cover crop acres were very low at first—about 9,600 acres in 2013—and stayed low through 2017. But they jumped sharply in 2018 to more than 94,000 acres, and even higher in 2019, reaching about 201,000 acres.

In the same study region, voluntary cover crops increased by about 5%, adding roughly 36,000 more acres.

Cash crop trends

The data also evaluated trends in the frequency of major cash crops grown before and after winter cover crops over time.

Over the study period, the share of soybeans in the study area planted the season before winter cover crops rose from approximately 4.75% to a high of about 8% in 2018 before slipping to around 6% in 2019.

The frequency of cotton and corn crops being planted before winter cover crops also increased between 2013 and 2019 but to a lesser degree.

When looking exclusively at what cash crops were planted after cover crops, a similar trend emerged. By 2019, 6% of soybean acres were planted after winter cover crops, an increase of 2% over 2013. Again, the share of corn and cotton acreage planted after cover crops also increased from approximately 0.25% each to about 1.75% for corn and just over 2% for cotton.

When looking at year-to-year crop rotations, both with and without the use of cover crops, the researchers found that a soybean-to-soybean rotation without cover crops was the most frequent pattern, representing 21% of acreage in the study area in 2013 and dropping slightly to 18% in 2019.

The soybean-to-soybean rotation with cover crops represented 2% of acreage in 2013 and growing to 3% in 2019.

During the study period, the average total soybean cropland was about 3.2 million acres. Rice followed with about 1.3 million acres, then corn with 700,000 acres, and cotton with 400,000 acres.

How they did it

Nalley’s team of researchers overcame several technical obstacles to produce the results for this study, including occasional GPS inaccuracies for specific cover crop locations.

Google Earth Engine and NASA Landsat 8 Operational Land Imager Top of Atmosphere sensing was used in combination with the USDA-NRCS cover crop dataset to obtain pixel-based image identification of cover crops. The Landsat 8 offered 30-meter spatial and 16-day temporal resolution remote sensing. With a cropland data layer, the data allowed using a pixel-based method to identify cover crops.

The ground cover months of November to March were used to identify the cover crop areas. To adhere to USDA-NRCS data-sharing agreements and to ensure data privacy, classified acreages to identify crop rotation and cover crops were aggregated at the county level for subsequent mapping activities.

Cloud cover was eliminated from the NASA Landsat 8 satellite data, and a machine learning algorithm was used to identify the cover crop area with multiple spectral reflectance bands and indices.

More information: Zobaer Ahmed et al, Satellite Remote Sensing Reveals Voluntary Cover-Crop Adoption and Crop-Rotation Hotspots in the Mississippi Alluvial Plain, PLOS One (2025). DOI: 10.1371/journal.pone.0331797

Citation: Voluntary wintertime cover crop adoption up 5% in Arkansas (2025, December 16) retrieved 16 December 2025 from https://phys.org/news/2025-12-voluntary-wintertime-crop-arkansas.html

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