Consider Winter Cover Crops for Hay Before Planting Cotton Next Year
Authored by: Cheryl Mackowiak, UF/IFAS Crop and Forage Soil Scientist, North Florida Research and Education Center (NFREC) – Quincy
Keeping your land covered with some type of vegetation during the winter months provides various benefits, such as soil erosion protection, weed control, breaking pest cycles, capturing nutrients, potential improvements in soil health, and even grazing or haying opportunities. Researchers at the University of Florida are investigating the potential benefits of keeping the ground covered 24/07 by testing cereal rye and crimson clover options managed as either cool-season grazing, cover crop, or hay crop preceding a summer cotton cash crop. They also included a four-way brassica-mix cover crop treatment. They are aiming for short-lived annual forage species to minimize interference with spring cotton land preparations. The featured image above shows an overview of a winter cropping study at NFREC-Quincy, FL prior to April termination that was followed by cotton in 2026.
At the North Florida Research and Education Center (NFREC) Quincy, researchers are evaluating November planting cereal rye ‘Florida 405’, a very early maturing new variety that is similar to ‘Florida 401’ in maturity and growth, but with a somewhat longer harvest window, better rust resistance, and greater tillering. These two varieties are among the earliest maturing small grains in the Southeast U.S. There may be less need for chemical termination of this variety in the deep south, since it is typically finished by early May, if planted by early December. These varieties are also attractive options for those who use strip tillage with their summer crop (Figure 1).
Figure 1. Two months after cutting a rye winter crop for hay (left) or managed as a cover crop (right). Cotton ‘DP2038 was planted into strip-tilled research plots. Credit: Cheryl Mackowiak, UF/IFAS–
Cereal rye may not be as nutritious a hay option compared to triticale or oat, but it will produce forage much faster than any of the other small grain options or annual ryegrass grown in the deep south. Managed as a hay crop preceding cotton, we applied 60 lbs. of nitrogen (N)/acre and drilled 100 lbs. seed/acre, compared to using only 30 lbs. N/acre and 25 lbs. seed/acre when managing it as a cover crop. We are also testing ‘Dixie’ crimson clover, since it is early maturing annual legume, the seed is reasonably priced, and it might provide additional pop-up nitrogen fertilizer to the following cotton crop. As a hay crop, we broadcasted 30 lbs. crimson clover seed/acre, compared to 15 lbs. seed/acre when managed as a cover crop. No other fertilizers were applied to any of the hay or cover crop treatments. We also tested a rye/crimson clover blend (25/15 lbs. seed/acre, respectively). Surprisingly, the cover crop treatments with rye performed better than treatments managed as hay (Figure 2). The first-year rye managed as hay yielded more. We even included a brassica blend managed as one of our cover crop treatments. The blend was comprised of equal parts common kale, canola (aka rapeseed), purple top turnip, and tillage radish (at a combined rate of 8 lbs. seed/acre). Glucosinolates (potentially natural weed inhibitors) are released by many brassica species, and their tap roots may help with subsoil nutrient scavenging and improve soil structure allowing for greater water penetration, particularly during intense rainfall events.
Figure 2. Winter season dry forage production under different winter crop management options. Color bars represent means or 4 replicates. Bars sharing the same letter are of similar yield. Vertical bars represent ± standard error.
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This is an ongoing project but a few general observations over the past couple of winter cropping seasons included additional plant-available soil nitrogen left under crimson clover plots during the winter and even during much of the summer cotton crop. This suggests that the crop is acting as a slow-release fertilizer even during cotton production. Others have reported roughly 25 to 75 lbs. of plant available nitrogen from crimson clover cover crops. We would like to validate that benefit while also cutting the clover for hay. Although we have found 20% larger cotton plants following crimson clover (under cover and hay management) in 2025, lint yields were similar with those following fallow or treatments with rye (averaging 1,700 lbs. lint/acre). We are repeating the same treatments on the same land to determine longer term impacts of winter cropping systems on soil health and the longevity of repeated cotton plantings (no yearly crop rotation).
Growing rye or crimson clover as a hay crop may provide some additional economic benefits. More specifically, crimson clover hay is highly nutritious and may demand a good price if sold as 50-pound square bales. Based on this spring’s winter crop clover harvest of approximately 1 ton/acre dry hay and $10 square bales, one might gross up to $400/acre. Of course, this needs to be balanced against fuel, labor, and other input costs. It is too soon in our study to determine if the cost of substituting cover crops for winter hay crops will hinder potential soil health benefits but that is what we will evaluate in the coming seasons.
Nearly half of brassica yield was in the form of storage roots/tubers near the root surface. These materials break down readily (within weeks) and little evidence remains of the cover crop in the following two months. The brassica mix total dry mass (above and belowground) was just over 0.5 tons/acre (Figure2). Interestingly there is at least one area farmer who manages wild mustard weed as a cover crop for its various benefits, such as it displaces other harder to kill weed species, it comes in on its own after the cotton crop (no seed or planting costs), and it is easy to kill in the spring. It seems that when it comes to keeping the land covered, one farmer’s bane is another farmer’s boon!
There are many winter vegetation options and management strategies to choose from, depending on your goals. Our main goal, besides increasing farm income while minimizing soil nitrate losses from production fields, is to provide economically reasonable options for keeping your soil healthy and field covered by expanding the use of annual cool season forages.
If you are a Florida cotton farmer and have interest in trying a crimson clover or cereal rye winter crop on one or two acres prior to your spring cotton planting, please contact Dr. Cheryl Mackowiak by September to discuss possibly serving as an on-farm demonstration site this fall. We want to see how much our results translate to real-world conditions. This project is sponsored by Florida Department of Agriculture and Consumer Services (FDACS) Office of Agriculture Water Policy (OAWP).
by Doug Mayo
