Chicken litter in fertility programs increases with
|By Leo Espinoza|
The high price of fertilizers has resulted in an increase in the use of chicken litter as part of a farmer’s fertility program. Extension publication “The Use of Chicken Litter in Row Crops” can be found at the following link: www.uaex.edu/Other_Areas/publications/PDF/FSA-2147.pdf.
Perhaps the most important recommendation is to obtain an analysis of the litter as close to the time of application as possible. Below is a table with the statistics of 100 samples of broiler litter analyzed by the University of Arkansas Agricultural Diagnostic Laboratory during 2008. The wide range of litter moisture and nutrient contents listed in Table 1 underscores the importance of having the litter analyzed.
The rate at which the nitrogen becomes plant available is particularly affected by temperature and moisture. The optimum temperature for mineralization to proceed is reported to be 75 degrees F and higher. This is important to know as wheat farmers may consider applying litter in February and March to meet the nitrogen requirements of the crop.
What Researchers Have Reported
Other researchers have reported that when temperature and moisture conditions are near optimum levels, a large portion of the nitrogen is mineralized (becomes plant available) in four to six weeks.
It appears that there is no difference between fresh and pelletized chicken litter in the supply of major nutrients. However, the pelletized formulation is significantly higher in price than fresh litter. There are some sources of pelletized litter that may show higher nitrogen analysis resulting from supplementation with chemical fertilizer, typically ammonium sulfate.
Phosphorus/Potassium In Chicken Litter
For fertility purposes, assume that 90 percent of the phosphorus and potassium can become plant available during the first year. The phosphorus applied with the chicken litter, just like commercial P fertilizers, can be tied up or fixed.
The position of the University of Arkansas Division of Agriculture is to recommend chicken litter based on phosphorus requirements. Applying chicken litter to meet the nitrogen requirements of a crop may result in phosphorus application rates that exceed the amount a crop may need to achieve optimum plant growth.
A study conducted in Alabama to assess the effects of long-term applications of broiler litter and ammonium nitrate showed that surface soil pH levels of plots receiving ammonium nitrate had decreased by 0.1 to 1.0 units (depending on N rate), while soil pH of plots receiving broiler litter remained unchanged or showed higher than initial levels (especially for high litter application rates). The soil at this location was fairly sandy and had a low CEC.
Such a dramatic change would not be expected to occur as fast in soils with higher buffering capacity (high CEC).
Application Of Chicken Litter
Please refer to fact sheet FSA 1040 “Calibrating Chicken Litter Spreading Trucks” http://www.uaex.edu/farm-ranch/crops-commercial-horticulture/soybean/podcasts/number70.aspx#Script for information on calibrating application equipment.
Failing to properly calibrate application equipment can result in areas over- or under- fertilized, resulting in streaking.
Results from a study in Colorado, using 10 litter spreader trucks, showed that seven out of 10 spreaders had patterns that were off-center. Another one of the spreaders had one side with 7.5 times the amount of manure on it than the other side. Some of the trucks did not seem to be loaded evenly (trucks were loaded according to common procedure). They also reported swath widths ranging from 7.5 feet to 16.1 feet, with an average of 11.1 feet.
Results of a calibration workshop in Arkansas, using 10 litter trucks, showed that the litter loads contained in such trucks varied in density from 27.9 to 38.2 cubic feet.
Things To Remember
The University of Arkansas recommends applying chicken litter based on phosphorus requirements of the intended crop.
Leo Espinoza is a soil scientist with the University of Arkansas, Department of Crop, Soil and Environmental Sciences. Contact Espinoza at (501) 671-2168 or email firstname.lastname@example.org.