This is the SCNY Team’s third full week of monitoring alfalfa heights for first cutting quality in 2021. A full report for the six-county region can be found in the following link: Alfalfa Height Reporting Sheet 5.18.2021
Start Your Engines – Mowers that is!
We experienced some great heat this past week that really got alfalfa moving. Across all locations, average heights increased 4.5″, with locations west of I-81 in Onondaga County gaining close to 6-7″ in some areas. Slowest growing again this week were locations in Cortland County, reporting on average still less that 4″ increase over last week’s heights. Across most locations, mixed stands of grass/alfalfa are ready to be harvested. In fact, many of our educators reported seeing hay being knocked down across our region. When alfalfa reaches 22″, a stand that is 50/50 alfalfa/grass has reached its prime quality and is ready to be cut. Heights in Western Onondaga, Tioga, and Chemung have reached that height on average for fields we measure. Broome and Tompkins are just about to reach that height (averaged 20″), while Cortland and Eastern Onondaga are just a little further behind (averaged 16″).
In much of the region, save Cortland County and parts of Onondaga County, grass may be and probably is past prime quality. Focusing on fields with a higher content of alfalfa will give you the highest quality potential right now.
We also saw lots of field work being done across the region and lots of corn being put in. If you don’t have the manpower to harvest first cutting while planting your corn crop, it’s best to park the corn planter and focus on harvesting your first cutting at peak quality. NDF in standing hay crop will gain more quickly than corn being in the ground will mature.
Why Use Alfalfa Height for Prediction?
We utilize alfalfa heights for targeting peak quality of all fields, as research as shown it to be the best indicator of peak quality.
As a reminder, for prediction of NDF content, the height of alfalfa as an indicator is as follows:
- 100% grass stands – cut when nearby alfalfa is 14 inches tall (achieves 50% NDF)
- 50/50 grass/alfalfa stands – cut when nearby alfalfa is 22 inches tall (achieves 44% NDF)
- 100% alfalfa stands – cut when alfalfa is 28 inches tall (achieve 40% NDF)
Predicted days to cut are based on daily NDF increases for grasses of 1.0% point, 50/50 mixed alfalfa/grass stands of 0.8% points, and alfalfa of 0.5% points and are adjusted for the coming week’s weather. Typically NDF increases about 0.8 to 1.2 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 warm/cool weather.
A Brief Look at Growing Degree Days
On average, locations in our region gained about 127 GDD (B32) in the last week. Median increase was 125, low was 100 GDD (Jordan) and max was 147 (Lansing). Looking at the season to date of Lansing, the last week trended close to 15- and 30-year averages, but the next week looks like a steep incline in GDD. This shot of heat may make hay crop mature quickly, so being nimble for conditions in your area will ensure you’re ready to harvest when the crop has reached it’s prime potential.
Next Report …
Look for our next and final report of monitoring heights to come out on Wednesday, May 26th. In the meanwhile, if you can’t get out to check your fields, call one of us on the team. We’ll be glad to help out.
Special thanks to our CCE Educators who are helping me measuring fields this year!
Donette Griffith, Liz Alexander, Dana Havas, Jenny Smith, Dave Skeval, Mary Kate MacKenzie & Fay Benson
THANK YOU!