Height indicators alfalfa and grass for NDF content are below:

• In general we say 100% grass stands should be cut when nearby alfalfa is 14 inches tall to achieve the desired 50% NDF.
• Begin cutting 50/50 mixed alfalfa and grass stands when nearby alfalfa is 22 inches tall for the desired 44% NDF.
• Begin cutting 100% alfalfa stands when alfalfa is 28 inches tall for desired 40% NDF. 

Predicted days to cut are based on daily NDF increases for grasses of 1% point, 50/50 mixed stands of 0.8% points and alfalfa of 0.5% point. NDF usually increases about 0.8 to 1.2/day for grasses expecting the lower end of that range in cooler weather and the higher end in warmer. Alfalfa NDF increases about 0.4 to 0.7/ day again depending on temperatures. Predictions are adjusted for the coming week's weather and right now assuming normal growth.

In the attached spreadsheet locations around the region are listed where we have measured alfalfa height. You can use the location and elevation as a guide to conditions that may be similar to your farm.

The 2018 hay crop is considerably behind from our 2017 harvest schedule, especially for May 10th. An alfalfa height of 9 inches or less is too low to be used by the equation we have which is why you see "Too Early". On May 10, 2017 the alfalfa averaged 15 inches tall and only 2% of the fields were 13 inches or less. As of today, May 10, 2018, alfalfa is averaging 9 inches tall and majority of field measured are 9 inches or less. That's quite a difference!

The table below indicates no grasses are ready to be cut today. However, pay attention to locations near you for predictions for grasses ready to harvest by next week. The continued warm temperatures through the weekend along with some rain in the forecast will surely increase growth and our predictions.

It is important that you get first cutting off in a timely manner for quality purposes, so please communicate in advance with your team on how you are going to continue planting corn and successfully harvest 1st cutting. Additional fields to be added to next report.
Alfalfa heights have jumped up considerably from last week averaging 19 inches tall compared to 9 inches on May 10. As of May 17 we are showing 80% of fields if 100% grass should be cut. Your mixed stands will reach desired NDF levels by the weekend and will be ready to harvest over the next several days. Remember with mixed stands to assume there's more grass and to harvest sooner versus later to achieve the desired NDF level. Plan accordingly and be sure to watch the weather so that you know where to set your priorities…continue to plant or park and harvest 1st cutting (quality vs. tonnage).

Next report will be May 24.





Alfalfa Height Reporting Sheet 2018 Week 2 (pdf; 192KB)


Alfalfa Height Reporting Sheet 2018 Week 1 (xlsx; 17KB)