Wheel traffic can have a huge impact on alfalfa yield, a problem that may be exacerbated by this year’s wet weather in many states.

Last year, researchers at the University of Wisconsin, Madison, and Agripro Biosciences, Napier, IA, compared yield of plots with and without wheel traffic. The traffic was in the form of a 100-hp tractor driven across plots three times. It was applied five days after the first cutting.

Traffic reduced yield in later cuttings by 27% to 88%. Reductions on farms would be lower, because damage to soil and alfalfa crowns only takes place in wheel tracks. But growers would be wise to minimize traffic damage, say the researchers.

Their advice:

  • Use small tractors when possible.
  • Avoid unnecessary trips across the field when harvesting.
  • Consider using larger equipment to have fewer wheel tracks.
  • Drive on fields as soon as possible after cutting.