By Blake Jackson
Chicken litter is widely used by farmers in western Kentucky as an economical source of crop nutrients. According to the University of Kentucky's AGR-168 publication, broiler litter contains significant amounts of nitrogen, phosphate, potash, and several secondary and micronutrients.
Although not all of these nutrients become immediately available, applying a few tons per acre can still provide a substantial portion of a crop’s fertilizer needs.
However, the success of chicken litter depends on factors such as soil conditions, nutrient availability, litter quality, and application accuracy. In one Kentucky field, a grower applied three tons of chicken litter per acre after drainage tile installation and major land grading.
To compare nutrient performance, strips of ammonium sulfate (AMS) and diammonium phosphate (DAP) were also applied before planting.
Researchers analyzed aerial imagery collected in late May using the Triangular Greenness Index (TGI), a vegetation indicator that estimates crop greenness and chlorophyll levels.
The images showed healthier crop growth where supplemental commercial fertilizer had been applied compared to areas receiving only chicken litter. While disturbed soil conditions may have influenced these results, the imagery also revealed another important issue.
Distinct bands of crop growth closely matched the spread pattern of the chicken litter application. Areas receiving the center of the spread displayed stronger crop vigor, while the edges showed weaker growth, indicating uneven nutrient distribution.
This variability was likely made worse because the litter had been stored outdoors and exposed to rainfall. Increased moisture can alter litter weight and reduce its ability to spread evenly, creating streaks of over- and under-application.
The findings emphasize that proper poultry litter management involves more than selecting the correct application rate. Protecting litter from rain, measuring moisture content, calibrating spreaders, and verifying spread uniformity are all essential for maximizing nutrient efficiency and maintaining consistent crop growth.
Additional aerial images collected later in the season also identified striping patterns associated with AMS and DAP applications.
The repeated bands of dark and light green crops suggest uneven fertilizer distribution caused by issues such as incorrect spreader calibration, improper swath width, or uneven fertilizer blending.
These observations highlight the importance of regularly evaluating application equipment to improve fertilizer efficiency, crop performance, and overall farm profitability.
Photo Credit: gettyimages-branex
Categories: Kentucky, Crops, Livestock, Poultry