First cutting should be taken very soon to achieve high quality forage, as seen by some of the estimated NDF levels in standing alfalfa crops around the state. Keep in mind that for dairy quality hay, alfalfa should be stored near 40% NDF and grass hay crops should have less than 55% NDF, which happens in the boot stage, or before the first flowering heads begin to emerge. Keep in mind also that the cutting, drying, and storing process results in raising NDF levels at least 3 NDF units above what it was in the standing crop at the time of cutting, and that assumes quick drying and ideal harvesting procedures.
So, it is time to be thinking about that first cutting and looking for weather windows of opportunity, especially along I-70 and south. Cutting forage for haylage or dry hay is certainly a gamble but waiting for the perfect stretch of weather can end up costing us through large reductions in forage quality as the crop matures and the fiber becomes less digestible.
Before cutting though, keep in mind that the soil should be firm enough to support equipment. Compaction damage has long-lasting effects on forage crops. We’ve seen many fields where stand loss in wheel tracks led to lower forage yields, weed invasion, and frustrating attempts to “fill in” the stand later.
Before cutting also keep in mind any harvest intervals required for any pesticides applied. We know some growers around the state have applied insecticides for alfalfa weevil control, so any pre-harvest intervals on the insecticide label have to be followed in order to feed the forage after harvesting.
Source : osu.edu