First Cutting Project is being conducted by Cornell Cooperative Extension of Chenango, Herkimer, Madison, Otsego and Schoharie Counties and the Central New York Dairy and Field Crops Team.
This is our second week of monitoring of 1st cutting for quality in 2012. Warmer weather and significant rain have moved the maturity a long across much of the region. Pure or mostly grass stands at lower elevations (below 1000 feet) need cut at this time. At higher elevations the prediction would be we are still a week away from grass harvest. Pure to mostly alfalfa stands appear to be 2-3 weeks away from harvest. Because alfalfa has been set back by frosts in some fields usually at higher elevations, weed competition is greater than normal; in particular dandelion but winter annuals as well. At this point it appears this competition is having an effect on the alfalfa.
As always use information in the attached table as a guide to know when to harvest by checking your fields! Next report May 15!
Most locations have alfalfa and grass height measurements, but a few only have grass and some only alfalfa so you may see blank spaces in the tables. At some locations the alfalfa is really too short to fit the equations, under 13 inches, so you see “Too Early” indicated. If a farm has harvested you will see “Cut” indicated. If you want to do it yourself check http://www.forages.org/joomla/index.php/tools for Excel spreadsheets that will make predictions of current NDF content in the field from your own measurements. Our feeling is that many times these calculations are within the error of scissor cut or grab sample results sent to a lab so you are encouraged to make your own measurements.
Here are numbers that are helpful when using alfalfa and grass height as an indicator of NDF content:
Begin cutting 100% orchardgrass stands when they are 19 inches tall and 100% reed canary grass stands when they are 21 inches tall for the desired 50% NDF. 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 the desired 40% NDF.
The desired NDF for all grass fields is 50%, 50/50 mixed alfalfa and grass fields is 44%, and pure alfalfa stands is 40%. Predicted days to cut are based on daily NDF increases for grasses of 1% point, 50/50 mixed stands of .8% points and alfalfa of .5% point. Typically NDF 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 warm. Alfalfa NDF increases about 0.4 to 0.7/day again figuring the lower end of that range with cool temperatures and the higher in warm. Predictions are adjusted for the coming week’s weather and right now we are assuming normal growth.
