Questions & Answers

 

Warren C. Thompson National Forage Specialist: America’s Alfalfa

It has been known for years, that the more frequently a crop is harvested, the higher the feed quality. Yet, when alfalfa is harvested too frequently, yields drop and the plant suffers from the ability to produce food reserves in the crowns and roots. Without recovery time, the volume and often persistence are also curtailed.
 
 Every alfalfa plant breeder I have known in the past 40 odd years has three goals to improve yields, persistence, and quality. Most of them approach these goals by breeding for disease control (resistance), insect (resistance), and survival under pressure.
 
 It has been known for years, that the more frequently a crop is harvested, the higher the feed quality. Yet, when alfalfa is harvested too frequently, yields drop and the plant suffers from the ability to produce food reserves in the crowns and roots. Without recovery time, the volume and often persistence are also curtailed.
 
 So producers wind up in a compromise of cutting late to preserve the plants and low quality forage or cutting early to get maximum quality and curtail life or the stand. In the last 10-20 years, breeders have produced varieties with more disease and insect resistance. Thus have developed stronger plants that bounce back quicker after harvest thus often producing more harvests each year with the bottom line of higher quality forage.
 
 So now we are faced with questions like the ones that follow:
 
 Q. Is there anything I can do other than harvest more frequently to improve hay quality?
 A. A thick stand of alfalfa means fewer weeds and fewer weeds equates into higher and more acceptable hay crop. When irrigation is available especially under extreme dry conditions, following a week of recovery time is a fantastic way to bring on new-vigorous growth without favoring annual weed growth. When growing alfalfa and grasses together, harvest to the advantage of the alfalfa not the grass. Soil test regularly and treat the needs as recommended. For most of the humid regions, the most opportune time to top-dress is early fall.
 
 Q. What do I need to look for in picking a variety for feed quality?
 A. Disease and insect resistance are two on the most profound criteria.
 
 Q. What about harvest frequency?
 A. For most growers (and weather will often interfere with these guidelines), once the alfalfa stand passes establishment year, many/most aggressive producers are mowing at a month interval between harvests. The last harvest four or more weeks ahead of the historical hard freeze date is still a great program but among growers is still being debated widely. BUT, if you should decide to harvest late and you farm in the snow/ice belt, be sure to leave 5-6 inch stubble to help prevent ‘ice smother’.
 
 Q. How close should alfalfa be cut?
 A. Above the crowns. When regrowth is well underway, usually because of inclimate weather during the harvest season, you should raise the cutter bar to ‘ prevent topping’ the immature (next crop) growth.
 
 Q. Is there a guideline to estimate days of growth and yield?
 A. Under the most ‘ideal growing conditions’, hay production yield is close to 100 pounds a day. This estimate will vary depending on fertility, water, stand density, disease and weed invasion resistance and weather temperature and possibly other factors.
 
 Q. Will the first year alfalfa measure up in quality with older stands?
 A. I doubt it. The first harvest should go to bloom and grow 65-75 days from seeding to harvest. Unless the grower is very careful, weed growth (including annual grasses) will usually be more of a concern on new stands. Put these two elements together and you will likely have less quality at least the first harvest that year.