First Cutting Updates - Utilizing Alfalfa Heights as a Predictor for Quality

The SCNY team is monitoring alfalfa heights again this spring to help predict quality and %NDF for first cutting hay crop. Alfalfa height has been proven to be a reliable indicator of NDF values in the field for alfalfa, alfalfa/grass mixed and all grass stands. Results will be compiled and emailed on a weekly basis - please feel free to forward on. To be included on the weekly email, or to be removed from the email, please contact Betsy Hicks, bjh246@cornell.edu.

UPDATES FOR THE WEEK OF MAY 15th, 2017:

Comments from Janice: Mowing has begun and it's right on for clear grass fields since orchard grass is heading and other grasses will be heading in the next week. Alfalfa is approaching or at 2 ft this week. Only occasional early buds found. With the adequate soil moisture and the predicted heat for the week ahead we have the potential to gain significant yield in the next week to alfalfa. The weather windows and percent alfalfa will drive when to target harvest of mixed stands. The time is near and the switch from corn planting to hay harvest may be necessary to capture high quality. Wet fields will be a factor to consider when planning harvest. In soils that have been saturated or even waterlogged over the last 3 weeks the alfalfa is obviously stressed. It's growing very slowing and in some fields actually going backwards. There are spots of significant winter damage, mainly crown heaving. These fields are going to have a disappointing yield and may be candidates for turning into corn after first cutting.

Comments for Southern Counties (Broome, Tioga, Chemung, S Cortland): Most fields saw a good 3" of growth from last week and are above that 20" mark. Hill ground maybe a bit less, but valley ground a bit more. Several fields of triticale and fields of grass have been mowed already, as well as some fields of mixed alfalfa/grass. Fields continue to be drier here than the northern part of the region (I didn't have to use 4wd to access fields this week!), so I would expect more mixed fields to be knocked down in the coming week. Predicted dates to cut for a 50/50 mix in the southern counties is the end of this week to beginning of next week. Forecast looks like rain Thursday/Friday with a decent weekend, although cooler than the heat we're getting today and tomorrow. Pure alfalfa stands still have some time to gain yield while maintaining quality.

Comments for Northern Counties (Tompkins, N Cortland, Onondaga): Fields saw similar growth to the southern counties in our region - a good 3" overall, hovering around that high teens to low 20's in height. The heat and sun in the next two days will hopefully help to dry out conditions. Predictions for peak quality for a 50/50 mix are looking like this weekend. Don't be fooled by the amount of alfalfa in the stand - often we overestimate the amount in the stand and harvest it later than what the grass's peak quality is. The weekend looks like decent weather, so getting on those mixed fields may be a good idea. We still have time to gain yield in higher percentage alfalfa fields without sacrificing quality. Pure alfalfa stands have time to gain for sure - predictions to cut are still out there to around Memorial Day. The 10-day forecast looks like a small percentage of rain every day, so waiting on the weatherman to figure out his forecast won't hurt quality and will gain tonnage on pure stands in the meanwhile.

Thoughts on pure grass fields that are past peak quality: If you are able to segregate your first cutting, you may want to leave your fields that are past peak quality and save them for dry cow or heifer feed and focus on getting your mixed fields in at peak quality. Certainly, field conditions will play a role, but yield can be a factor to take into account as well.

Please let us know conditions you observe while harvesting, and any comments back about the alfalfa height project are appreciated! We also welcome any sample results you would like to share, so forward them on me, bjh246@cornell.edu. You can also post harvest pictures on our team's Facebook page - https://www.facebook.com/SCNYDairyandFieldCropsTeam/ and use the hashtag #harvest2017.


Additional Information:

The numbers that are indicators for using alfalfa heights for NDF content are as follows:
• 100% grass stands should be cut when nearby alfalfa is 14 inches tall, to achieve 50% NDF
• 50/50 mixed alfalfa/grass stands should be cut when nearby alfalfa is 22 inches tall, to achieve 44% NDF
• 100% alfalfa stands should be cut when alfalfa is 28 inches tall, to 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.

The weekly email for the month of May will have a table of the locations around the region where we have measured the alfalfa height, as well as the elevation. 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. We now cover six counties throughout South Central NY, including Tioga, Chemung, Broome, Tompkins, Cortland and Onondaga. Other teams and associations throughout the state are also measuring fields. For more information, contact that county's association to find out if fields are being measured there.


Alfalfa Heights - Week of May 15th, 2017 (pdf; 229KB)