By Gary Sliworsky, Ag rep, Emo
Now is a good time to walk your hay fields and pastures to assess stand density and winter survival.
Here are some tips on assessing your forage stands:
Check your hay crop for early signs of green-up. In the case of alfalfa plants, look for firm white or pink buds just above ground level.
These buds should start to green up with the first few warm days.
Also, dig out a few alfalfa roots and slice them in half. Healthy roots will be firm with a white to cream colour interior.
Damaged roots, on the other hand, will be soft and/or spongy, and will have a discoloured or brownish interior.
In alfalfa, heaving greater than one-half to one inch in new seedings is serious. Such heaved plants probably will die over the next few months.
If fields must be replanted, it is important to make this determination as early as possible in the spring.
Second-year alfalfa stands should have eight-12 plants per square foot for optimal yield potential. For new alfalfa stands with a few bare spots, one option is to disk and re-seed or no-till alfalfa/grass mixture possibly with a cereal into the bare locations.
As for older alfalfa stands which have been thinned out, they can be frost-seeded early or re-seeded with a drill as soon as the ground firms up using either red clover (four-six pounds/acre), white clover (two-four pounds/acre), orchardgrass (four-six pounds/acre), or perennial ryegrass (five-six pounds/acre)—depending on the anticipated future life of the stand.
Red clover, orchardgrass, and perennial ryegrass all will be vigorous seedlings and able to compete with established alfalfa.
Perennial ryegrass, however, is much less likely to survive the winter.
Older alfalfa stands with less than four plants of alfalfa per square foot either should be rotated to a new crop or over-seeded with a forage other than alfalfa.
If perennial weeds are not abundant in an older alfalfa stand, the stand can be over-seeded with the species mentioned above.
Visual estimates of the ground cover of desirable forage plants also can be used to assess forage stands. This should be done when there is about six inches of growth.
Stands with more than 80 percent ground cover will produce excellent yields. Stands with 60-80 percent ground cover should produce fairly normal yields.
If winter-kill of alfalfa results in a predominately grassy field, treat it as a grass stand. When 50 percent or more of the area in the field has some grass plants or tillers, the stand should thicken with the application of nitrogen (N) fertilizer and produce reasonable yields.
Fertilizing thin grass stands with nitrogen normally produces higher yields than any attempt to inter-seed legumes into the stand.
It is critical to initiate a grass fertilization program early in the spring season. About 75-100 pounds/acre of actual N fertilizer applied at green-up will stimulate grass development in the spring and maximize grass production during the entire season.
When ground moisture is adequate, application of an additional 50 pounds/acre of actual N fertilizer after each cutting, except after the final harvest of the season, will keep grass stands productive.
Grasses must be cut early to produce a good quality forage.