Producing Quality Alfalfa Hay

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

Once you have selected the best variety of alfalfa, it is up to you grow the best crops possible and convert them to livestock feed. Whether you make hay or haylage (silage) or grazing or a combination of all of these systems, there are ‘rules’ that are to be followed. And these so called rules apply to all phases of planning and production.

The following conditions dictate quality:
1) Stand density
2) Purity of the stand
3) Harvest frequency
4) Leaf retention
5) Plant and leaf diseases
6) Soil fertility and moisture
7) Harvest regimen 
  

• Stand Density: Thick alfalfa stands produce higher quality forage than thin stands. An ideal newly established alfalfa stand is a uniform stand of 20 to 40 or more plants per square foot. Later, that number will drop as the more aggressive plants expand and compete for growing room. When stands drop below 5 plants per square foot, the plants are more stemy and vulnerable to weed invasion. This is a great time to decide whether to over-drill with grass, fill in with another legume, or plow and plant to other crops.
• A thick alfalfa stand reduces room for grass and weeds to grow. The healthier the stand is maintained with harvest frequency and high fertility levels, the higher the quality will be at harvest time.
• Frequent alfalfa harvests produce high quality hay and silage and lower per-harvest yields. Less frequent harvests are just the opposite; higher yields per cut but lower quality. Because of the way alfalfa grows along with temperature and moisture, compromises are necessary to devise a program that ‘lets plants live while harvesting good feed’. True, more farmers today are able to cut hay earlier in the spring followed by more frequent harvests especially in early summer than ever before. Why? It’s a matter of better varieties and the use of improved cultural practices. For example, first year spring alfalfa plantings are often harvested 65-75 days after planting. Remaining first year harvests are made at about 30-35 day intervals but stopped 5-6 weeks before the beginning of historic harsh winter season. Older stands are cut two to three weeks earlier in the spring. Second and third summer cuts are made more often than newly established plantings. These may be taken at 28-32 day intervals. In recent years, many dairy farmers who have turned to growing the grazing/traffic tolerant varieties have been harvesting at 20-24 day intervals. They do this to produce the highest possible protein and digestible dry matter levels realizing there will be lower yields per harvest. Such harvests can be devastating to hay-type alfalfa but apparently not so when growing varieties with this tolerance trait. Ordinarily, late harvests are delayed because of slow growth and smaller yields due to hot weather and moisture stress but growers should allow 5-6 weeks in the fall to build food reserves for winter survival and abundant next year crop harvests.
• Leaf retention is key to high quality alfalfa. The quicker and easier the hay is put in the bale or in the silo, the higher feed quality. Hay conditioners and drying agents have had a great impact on reducing weather exposure time and the necessity of turning windrows to air-dry.
• Plant diseases reduce alfalfa quality. Farm experience plus research and field experience have shown that ‘cheap’ seed can turn out to be the most expensive seed on the market. Seed costs for alfalfa stands that last 4-5 years represent 4-6% of the total production costs. Yet some farmers continue to buy ‘ bargain’ seed that costs big bucks when this seed dictates responsibility for low yields and a short lifespan.
• When dealing with natural rainfall, plan your harvests around high pressure and low pressure weather fronts as much as possible. Farmers with years of experience find that harvests that are delayed several days beyond the normal schedule reduce the quality of the current hay cut but when mowing, the succeeding crop is often ‘topped’ and yields and plant health are both jeopardized. Here is where common sense comes into play. Their conclusion: it may jeopardize the current harvest but by harvesting close to the established schedule, they may get this crop wet but can stay on schedule with succeeding harvests and the quality of those crops will be maintained as will be the life of the stand.
• The time of day a hay crop is harvested has a lot to do with quality. Harvesting in the early morning hours, while the atmosphere and plants are still moist seems to be the preferred time in most regions to cut and favor leaf retention. Harvesting in the late afternoon and early-evening hours favors the retention of higher nonstructural carbohydrates (TNC).

Summary: 1) as plants mature (age) between harvests, quality drops. 2). Immature plants yield less than mature ones. 3) Producers who develop a compromise between these two opposites have a good hay program.