Beef & Forage Publications

Using Broiler Litter in Forage Production

Broiler litter is widely used as a nutrient source in forage and hay production to replace costly commercial fertilizer applications. There are many valuable nutrients contained in broiler litter, however it’s composition can vary depending upon several factors including:

  • How often the litter is removed from the poultry house
  • The number of birds in the house
  • The depth of litter removed
  • The type and length of litter storage before spreading

For these reasons, proper litter analysis and spreader calibration are essential to determine the nutrients available for a specific crop. This aids in meeting the crop nutrient requirement while following recommended best management practices to reduce excess nutrient applications and avoid potential water quality problems.

The first step in proper litter analysis is to collect a representative litter sample for submission to a testing laboratory. Ten samples should be collected at different locations throughout the broiler house. One or two should be under or near the waterers and the remainder should be collected at randomly selected dry points throughout the house. Be sure to collect the sample from the same depth as the litter will be removed and take care not to contaminate the sample with soil.

Litter samples being collected from a manure storage pile should follow the same principles, be sure the sampling points represent the whole area. Collecting samples from deep within the pile is essential because the nutrient content near the surface may be different from that within the pile. Samples should be taken at depths between 18 and 36 inches.

It is important to collect about ½ pound of litter from each sampling point for the total representative sample. Place the individual samples in a clean container and mix throughly. Completely fill a heavy duty quart size plastic bag with the mixed litter and seal tightly. Samples should be iced down or refrigerated immediately after collection and submitted to the testing lab as soon as possible.

Once the litter has been analyzed and you have determined the amount to apply, the proper calibration of the manure spreader becomes essential. When calibrating manure spreaders it is important to record tractor speed, gear, RPM, and manure spreader settings. Before calibrating, the spreader settings should be adjusted so that the spread pattern is as uniform as possible. Overlapping adjacent application paths may be required to make the overall field application more uniform.

There are several methods that can be utilized to calibrate a manure spreader. Traditionally the "Land Area Method" has been used by producers to give a ball park estimate of the amount of manure being applied per acre. This method consists of weighing the amount of manure in the spreader before application and measuring the area over which the spreader load of manure covers. The application rate is calculated by dividing the weight (lbs) of manure into the area (acres) covered. This results in pounds per acre of manure applied. Portable scales for on-farm weighing of the loaded spreader and an accurate measurement of the area covered are required for this method to be reliable.

Another method of calibrating manure spreader application rates is the "Tarp Method". This method involves laying a tarp or plastic sheet on the ground and using the manure spreader to spread the litter on the tarp at the same gear and speed as will be used in the field. Collect and weigh the litter which is applied to the tarp after one pass. Repeat this procedure several times to get an average value of the litter applied on the tarp. The rate of application is determined from the weight of the litter collected and the area of the plastic sheet or tarp used. For example, if 10 pounds of manure are collected from a 10 x 10 tarp, the 10 pounds are divided by the 100 square feet area of the tarp, the resulting figure is multiplied by 21.78 (this is a conversion factor to give you tons/acre) . Therefore in this example the application rate is 2.18 tons per acre.

The following table is provided as an aid in determining the application rate of manure using the tarp method. The calculations have been done for three popular tarp sizes. Edges of a larger tarp can be folded under to make the size fit the table for convenience.

Tarp Method Calibration Chart

Size of Tarp

 

Pounds manure collected on tarp

8' X 8' Tarp

10' X 10' Tarp

10' X 12' Tarp

 

Tons of Manure Applied Per Acre

1

.34

.22

.18

2

.68

.44

.36

3

1.02

.65

.54

4

1.36

.87

.73

5

1.70

1.09

.91

6

2.04

1.31

1.09

7

2.38

1.52

1.27

8

2.72

1.74

1.45

9

3.06

1.96

1.63

10

3.40

2.18

1.82

11

3.74

2.40

2.00

12

4.08

2.61

2.18

13

4.42

2.83

2.36

14

4.76

3.05

2.54

15

5.10

3.27

2.72

16

5.45

3.48

2.90

17

5.79

3.70

3.09

18

6.13

3.92

3.27

19

6.47

4.14

3.45

20

6.81

4.36

3.63

21

7.15

4.57

3.81

22 7.49 4.79 3.99

 

 

cow handling