Mild winter conditions across much of the southeastern United States allow livestock producers to extend grazing well into the fall and winter months. This practice can significantly reduce dependence on stored feeds such as hay and purchased supplements. Cool-season forages, including tall fescue, annual legumes, ryegrass, and small grains like oats, wheat, and rye, are generally recognized as a lower-cost feed source compared to harvested forages.

Regardless of the forage species selected, achieving optimal production depends heavily on maintaining adequate soil fertility. In regions with concentrated poultry production, commonly referred to as the “Broiler Belt,” poultry litter is widely used as a spring fertilizer to improve pasture productivity. But does applying poultry litter to cool-season forages provide consistent agronomic and economic value?

Understand the litter details

Several factors must be carefully evaluated before deciding to apply poultry litter for fall and winter grazing systems. First, producers must match forage nutrient requirements with current soil fertility levels, ideally based on recent soil tests.

Poultry litter can vary in plant food makeup but is often touted as 3% nitrogen (N), 3% phosphorus (as P2O5), and 2% potassium (as K2O). Variability arises due to differences in moisture content, bird management practices, and how the litter is handled. For instance, elevated moisture levels can substantially reduce the nitrogen concentration, sometimes by nearly half. Additionally, “clean-out” litter, which accumulates over multiple flocks, generally has lower moisture content and higher nutrient concentrations than “decaked” litter, which is removed more frequently as moisture accumulates.

Poultry litter normally has a pH above 8. This higher pH can also intensify nitrogen loss through volatilization, reducing the amount of plant-available nitrogen.

Litter availability is another important consideration. During cooler months, many poultry producers limit litter removal to help maintain house temperatures and manage moisture. As a result, fall-available litter is often lower-quality material (like higher-moisture decaked litter) or material that has been stockpiled, potentially losing nutrient value over time. This further reinforces the importance of testing before purchase.

Challenges in the fall

Applying poultry litter to cool-season forages presents additional challenges due to environmental conditions. Nutrients in poultry litter are primarily in organic form and are not immediately available to plants. Instead, they must first be converted into plant-available forms through microbial activity in a process known as mineralization.

Mineralization rates depend on soil temperature, moisture, and the carbon-to-nitrogen ratio of organic material. In cooler fall and winter conditions, this process slows considerably, which can delay nutrient availability and reduce alignment with forage growth demands.

Furthermore, higher precipitation during the winter months raises the risk of nutrient loss through leaching and runoff. This not only reduces fertilizer efficiency but may also contribute to environmental concerns related to water quality.

Beyond agronomic performance, the economics of poultry litter application must also be evaluated carefully, particularly for cool-season annual forages, where nitrogen is typically the most limiting nutrient.

For example, annual ryegrass generally requires about 30 pounds of nitrogen per acre to produce one ton of forage. If nitrogen is supplied using a commercial fertilizer such as 34-0-0-5S (urea with sulfur) priced at $785 per ton, and application costs are approximately $10 per acre, the total cost comes to roughly $45 per acre.

To supply an equivalent amount of nitrogen using poultry litter with a nominal analysis of 3-3-2, approximately 1,000 pounds per acre would be required. For this to be economically competitive with commercial fertilizer, the litter would need to cost no more than about $90 per ton when applied at 0.5 tons per acre.

If litter quality is lower than assumed, higher application rates may be necessary, which lowers the break-even price further. In some cases, application equipment may only be calibrated for rates of two tons per acre or greater. At that application rate, poultry litter would need to be priced near $22.50 per ton to remain competitive on a nitrogen-equivalent basis. However, even at higher application rates, not all nutrients may be immediately plant-available due to the environmental and biological constraints discussed earlier.

Consider the season

The decision to apply poultry litter for cool-season grazing systems should be approached with caution. Variability in nutrient content, reduced nutrient availability under cool conditions, and higher risk of environmental loss all contribute to uncertainty in both agronomic performance and economic return.

In most cases, commercial fertilizers offer more consistent and predictable nutrient delivery for fall and winter forage systems. However, poultry litter can still be a viable option when its nutrient composition is verified through testing and when its cost is favorable relative to commercial alternatives.

Poultry litter is especially valuable for spring applications, when warmer temperatures and active microbial processes enhance nutrient availability. Ultimately, base decisions on careful evaluation of soil tests, litter analysis, application costs, and nutrient requirements.

The authors are associate extension professors with the Alabama Cooperative Extension System and Auburn University.

This article appeared in the August 2026 issue of Journal of Nutrient Management on pages 8 and 9.

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