It’s Almost Time: 1st Cut Alfalfa

It’s almost that time, 1st cutting of Alfalfa. With grass 1st cut almost underway in much of the state, alfalfa/grass and pure alfalfa stand cuttings are not too far behind. Making the decision on when to harvest alfalfa is a difficult one. For feed quality, it would be pre-bud, but from a plant health standpoint, it would be one-tenth bloom or full bloom.

If following Cornell NDF guidelines, use the following for 1st cut (taken from Cornell Cooperative Extension):

• 100% grass stands should be cut when nearby alfalfa is 14 inches to achieve 50% NDF
• 50/50 mixed alfalfa/grass stands should be cut when nearby alfalfa is 22 inches to achieve 44% NDF
• 100% Alfalfa stands should be cut when alfalfa is 28 inches tall to achieve 40% NDF

Take a break from your tractor and walk your alfalfa fields around the pre-bud stage. The crown will begin to sprout new shoots – showing that the previous generation is nearing completion and forage quality is high. Check for abnormalities while you’re out there too – leaf size, shape, color – may indicate an insect, disease, or fertility problem that is having an impact on plant health.

When checking your fields, do the following:

• Look at stems for discoloration and evidence of disease or insects
• Have a sweep net with you to check for insect presence. Don’t have one? Use your hat – but make sure you check for stinging insects before putting it back on! Sweep 10x and take a look
• Check the new growth on the crown – it signals crop vigor and time to bring in the mower

Check your mower height and adjust it so it doesn’t shatter new growth or damage crowns. For every ton of DM removed, removal of nutrients is 60# nitrogen, 12# phosphorus, 60# potassium, 5# magnesium, 28# calcium, and 5# of sulfur. Alfalfa will also respond well to boron – an essential micronutrient that is limited in the soil and highly leachable.

Applications following harvest of potassium, magnesium, sulfur, and boron will help maintain yields and plant health. Although alfalfa is an N-fixer most varieties are only 65-80% efficient in gathering enough N to support rapid growth, so do not forget the nitrogen. Adding N with topdress can be beneficial. Taking care of your alfalfa will help future forage quality and soil health.

As always, any questions or concerns about your crop, contact your local CaroVail location for help. And remember, take a break and be SAFE!