Kentucky Ag News
The economic value of applying poultry litter in the fall
University of Kentucky College of Agriculture, Food and Environment
LEXINGTON, Ky. - Spring application of poultry litter is ideal for maximizing the economic value of poultry litter but faces challenges that include wet soil conditions, lack of time to spread litter near planting, and availability of poultry litter in the spring. Therefore, it is a common practice in Kentucky to apply poultry litter in the fall. While not optimal from an economic, agronomic, or environmental perspective, producers still need to understand the economic value from applying poultry litter in the fall.
Poultry litter applied in the fall to fallow cropland will suffer from ammonium volatilization and leaching resulting in little to no nitrogen available to the crop come spring. This results in an economic value less than if applied in the spring. To evaluate the economic value of poultry litter applied in the fall, first assume that soil test recommendations indicate the need for phosphorus and potassium. Also, assume that “as received” poultry litter has a nutrient content of 50 lbs of nitrogen, 56 lbs of phosphorus, and 47 lbs of potassium (average for Kentucky). With current fertilizer prices of $560/ton for anhydrous ($0.32/lb N), $435/ton for MAP ($0.35/lb P2O5) and $289/ton for potash ($0.24/lb K2O), the expected value of poultry litter applied to fallow cropland in the fall is $28/ton. This value should cover the price paid for the poultry litter, transport, and application to compete with commercial fertilizer when applied in the fall. The value of poultry litter increases to $33/ton if it is spread in the fall to cropland that has a cover crop planted.
If availability of poultry litter in the spring is a concern, stockpiling litter purchased in the fall can be an option if local, state and federal regulations allow. With the correct storage techniques and a properly staked litter pile, producers can expect minimum nutrient loss for spring application. If the same commercial fertilizer prices hold, the average poultry litter in Kentucky would have a value of $38/ton if properly stored and applied in the spring. If commercial fertilizer prices change come spring, the value for poultry litter can be seen in Table 1.
The poultry litter values for the spring assume all fertilizer (N, P2O5, and K2O) increase or decrease by the same percent. Even if current fertilizer prices decrease by 20%, the economic value of litter stored properly in the fall and applied in the spring is greater than poultry litter applied to fallow cropland in the fall ($30/ton vs. $28/ton).
The value of poultry litter differs in the fall if applied to pastures or land for hay production. If applying poultry litter to an established stand of alfalfa with a legume mix of <25% of the stand, the average poultry litter in Kentucky at current commercial fertilizer prices has a value of $42/ton. The value of poultry litter will vary based on grass type, established stands vs. new seeding/renovation, and whether the land is used for hay, pasture, or silage.
Since the value of poultry litter is dynamic and always changing, decision tools have been developed so producers can enter soil test data, nutrient content of measured litter, commercial fertilizer prices, and management practices of poultry litter applied to determine the value. Tools for applying poultry litter to both grain crops and land in hay/pasture/silage are available and can be found at uky.edu/Ag/AgEcon/shockley_jordan.php
This article was written by Jordan Shockley, assistant Extension professor at the University of Kentucky College of Agriculture, Food and Environment. The article first appeared in the October 28 edition of Economic and Policy Update.