Planting a Cover Crop before Harvesting Peanut Extends the Grazing Season in Integrated Crop-Livestock Systems

Trumpp, K. R., Dubeux, J. C. B., Mendes, C. E., Ercole, T., Medeiros, M. L., Rodrigues, D., Sganzerla, K., da Cunha, M. V., Magalhaes, A. L. R., Garcia, L., Mota, A., Ruiz-Moreno, M., UF/IFAS North Florida Research and Educaiton Center – Marianna

Introduction 

Florida farmers harvest more than one million acres of field and row crops (USDA, 2026), and 95% of this crop land is fallow during the winter. The fallow land brings many challenges to environmental sustainability and farm profitability. As the seasons progress, with the land uncovered, one of the problems associated is soil erosion, either by wind or rain runoff, enhancing nutrient losses. In fact, nitrogen is mainly affected since it is a very mobile nutrient and can be lost through leaching, producing eutrophication (nutrient pollution) of water bodies (Crews & Peoples, 2004) and increasing contamination of drinking water. In addition, weed infestations on fallow land may require greater use of chemical products to reduce weed pressure during the cropping season. At the same time, leaving highly productive land fallow represents a potential missed opportunity to develop winter cropping systems that could generate extra income while improving soil health.

Establishing cover crops in those scenarios represents a sustainable alternative since it brings a myriad of benefits, often described as ecosystem services (Blanco-Canqui & Ruis, 2020). Cover crops improve the overall soil health (Bhadha et al., 2021), help reduce soil particle and nutrient losses, control weed pressure more efficiently (Osipitan et al., 2019), and represent a forage source for livestock production. Despite all these benefits, the use of cover crops has not been implemented on a large scale in the region, thus suggesting the need for more research to find alternative implementation strategies.

The most used cover crops in Florida are oats (Avena sativa L.), which can be established at different times. Usually, cover crops are planted after the harvest of the warm-season row crops (e.g., peanut, cotton, among others), ranging between October and December, depending on cash crop harvesting times and rainfall patterns. Planting techniques include no-till, and when the cover crop is intended for livestock production utilization, it is established and ready for grazing around January. Nevertheless, advances in technology have opened new pathways, and with the development of agricultural drones, seeds can be spread before row crop harvest. This represents a potential alternative to reduce the time the soil is uncovered, protecting it from degradation, as well as weed encroachment, while gaining grazing days for livestock herds.

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Tractor vs drone seeding study

 A cover crop seeding study was conducted at the North Florida Research and Education Center (NFREC), Marianna, Florida. The study consisted of evaluating the use of two different seed broadcast methods (tractor vs. drones), at two different times (before or after peanut harvest). Thus, we hypothesized that by broadcasting seeds before the peanut harvest, we would gain time as compared to the common practice of planting the cover crops following row crop harvest. The objectives of this study were to quantify the herbage ground cover, herbage accumulation, light interception, leaf area index, and plant nutritive value (including crude protein and in vitro digestible organic matter).

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Experimental design and material and methods

The study was conducted in a randomized complete block design. Treatments consisted of the combination of planting method and time (either tractor or drone, and before or after the peanut harvest). Plots measured 18 ft wide by 36 ft long. The planting seeding rate was 151 lbs. per acre^-1. The first seeding took place before digging on September 10th of 2025, and the second seeding two weeks after the first one, which was on September 23rd, after peanuts were harvested (Figure 1). On September 12th, the peanuts were dug and picked on September 15th. On October 15th, 250 lbs./acre of 20-10-20 fertilizer was applied to all plots.

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Sampling was conducted every two weeks for all herbage responses. Herbage (vegetative growth) was measured using the double sampling technique. The ACCUPAR LP-80 Ceptometer (Meter Group, 2026) was utilized to estimate the canopy interception by measuring photosynthetically active radiation (PAR) and the leaf area index (LAI). The PAR is the radiation in the 400-700-nm waveband, which represents the portion of the spectrum that plants use for photosynthesis, while LAI is the area of leaves per unit area of soil surface.

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Preliminary results

Greater ground cover resulted from seeding oats by tractor before digging the peanuts (which was around 80% of total soil cover). Following this, seeding by tractor after digging the peanuts and with a drone before digging the peanuts were not statistically different from each other and ranged between 60 to 65% (Figure 2). Maintaining soil cover is highly important to avoid soil losses via soil erosion and runoff (Langdale et al., 1991; Zhou et al., 2008; Zuazo & Pleguezuuelo, 2009). Besides, this ground cover is highly important to reduce weed pressure and the need for chemical applications (Osipitan et al., 2018).

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Herbage accumulation was different among seeding methods and times. We observed greater herbage accumulation with the tractor and drone before harvesting the peanuts (Figure 3). Broadcasting the seeds before the harvest of the row crop might be beneficial for the cover crop, since the spread seeds are incorporated into the soil, improving the germination as well as the establishment, due to higher seed-to-soil contact. Regardless, this represents a potential strategy for producers utilizing their cover crops for grazing, plus early seeding in September can potentially help farmers include oats as part of their cover crop rotation, as well as provide forage in earlier stages for feeding livestock (Figure 4).

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Uniformity of seed distribution is crucial to obtain uniform ground cover. To improve the cover crop performance and maximize benefits, calibrating the machinery is key to obtain consistent spread of seeds, either by tractor or drone, making sure to deliver the seeds in the right pattern and to achieve an even ground cover. Seed distribution can be improved by good machinery calibration, which must be according to the weight of the seeds, since different varieties have varying weights, and heavier seeds spread further than lighter seeds. Nevertheless, the ground cover is affected by the digging of the peanut, where there is incorporation of the seeds, and the overall uniformity of the cover crop is affected (Figure 5). Most cover crop seeds are very small, and they don’t require much soil cover (MSU, 2026). Still, some challenges related to the uniformity of seed distribution have to be studied, yet greater homogeneity could be obtained when seeds are spread in greater areas, especially when drone applications are utilized.

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The cost of seeding the cover crop by a tractor was around $5 to $18 per acre, depending on the location and production area, while hiring a drone applicator typically ranges from $10 to $30 per acre, depending on factors like field size, location, seed type, and special waivers needed (Caillouet, & Myers, 2025). Considering the average cost of each planting method (tractor $11.5 and drone $20), and resulting in similar herbage accumulation, both practices provide an option for early cover crop establishment. However, the drone application will cost around 74% more than tractor applications.  However, the drone seeding could be contracted out saving valuable tractor operator time during the busy peanut harvest season.

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Summary and conclusions

Seeding cover crops before harvesting peanuts represents an alternative to extend the grazing season in integrated crop-livestock systems. Broadcasting oats onto standing peanut fields resulted in more successful establishment than when oats were seeded after peanut harvest. Still, further research is required to overcome challenges related to the seed distribution as well as other remaining drone inter-seeding practices.

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Acknowledgement:  This work is supported by the National Institute of Food and Agriculture, project award no. 2025-68012-44229, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

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