First Cutting Updates: Coming to a Field Near You!

Alfalfa height at optimum mixed stand NDF

The SCNY team is planning to monitor alfalfa heights again this spring to help predict quality and %NDF. Alfalfa height has been proven to be a reliable indicator of NDF values in the field for pure alfalfa, mixed alfalfa/grass and all grass stands. The team wants to identify fields that can be measured on a weekly basis.

If you have fields that we can come out and measure, please let Janice or Betsy know! Results will be compiled on a weekly basis –to receive weekly email/text updates, please contact us at 607-391-2673 with your email address/cell phone number.

Indicators for using alfalfa heights to predict NDF content are as follows:

  • 100% grass stands should be cut when nearby alfalfa is 14 inches tall, to achieve 50% NDF
  • Begin cutting 50/50 mixed alfalfa/grass stands when nearby alfalfa is 22 inches tall, to achieve 44% NDF
  • Begin cutting 100% alfalfa stands when alfalfa is 28 inches tall, to achieve 40% NDF

Predicted days to cut are based on NDF increases of 1 percentage point per day for grasses, 0.8 percentage points per day for 50/50 mixed alfalfa/grass stands, and 0.5 percentage points per day for pure alfalfa. Predictions are adjusted for the coming week’s weather.

Typically NDF increases about 0.8 to 1.2 percentage points per day for grasses, with cooler weather being the lower end of the range and warmer weather being the higher end. For alfalfa, NDF increases about 0.4 to 0.7 per day, also dependent upon weather.

The weekly email features a table of the locations in the region where alfalfa heights are measured, including elevation, and target date for harvest. Even if your fields aren’t measured, you can use the location and elevation as a guide to conditions that may be similar to your own.

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