With a shortage of good forage, should farmers be trying to get 4 cuts of alfalfa/grass this year? There may be enough moisture to consider 4 cuts, there is some risk to the stand. The attached article has two methods of estimating the risk.

1. Table 1, Fig. 1 & 2. Our long time recommendation of 500 GDD (C) between the last 2 cuts. The time interval can be from 5 to 8 weeks (Table 1), depending on when the last cut is made. The graphs show you the 30-year historic weather data window (shaded area) where you should not be cutting, to accumulate 500 GDD between 3rd cut (y-axis) and final cut (x-axis). The red line represents GDD accumulation in an average year.

2. The other option (Fig. 5 & 6) is to make sure you either accumulate more than 500 GDD OR less than 200 GDD after the final cut. Accumulating more than 500 GDD assumes you have recharged root reserves, accumulating less than 200 GDD assumes you have not depleted root reserves significantly.

So for a mid-August 3rd cut and a late Sept. final cut, both methods agree that this should present a minimum risk. Where the methods deviate is if you are cutting around the first of Sept. The first method says that is fine, as long as you have accumulated 500 GDD before that cut. The second method says that cutting around the first of Sept. is the worst possible time to cut, where you have essentially zero chance of either accumulating less than 200 GDD or more than 500 GDD after that last cut.