Manure Spreader Calibration

Daniel H. Smith, Jamie Patton, Kolby Grint, UW-Madison Nutrient and Pest Management Program, University of Wisconsin-Madison

Manure spreader calibration is necessary for determining manure application rates and properly crediting manure nutrients. These credits are extremely valuable in 2022 and 2023 due to high commercial fertilizer prices.

  • Calibrating a manure spreader is simple.
  • First, the manure spreader needs to be filled with manure.
  • Next, the weight of the tractor and full manure spreader needs to be recorded. This can be done using portable axle scales or a large machinery scale, such as the scales commonly located at grain elevators and Cooperatives.
  • Then, manure needs to be applied to a pre-determined field, simulating a typical manure application on your farm.
  • After spreading, the weight of the empty manure spreader needs to be recorded.
  • The final in-field step is to measure the area covered with the spread manure. The width and length should be measured to calculate the total acreage spread.

Using this worksheet, calculate how much manure was applied and estimated manure nutrient credit.

Manure spreader calibration video-
https://www.youtube.com/watch?v=m9LAsOgVN-g

Manure spreader calibration worksheet-
https://ipcm.wisc.edu/download/pubsNM/KnowHowMuchYouHaul.pdf