NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

December 23, 1998

CRP Acres Dormant Seeded this Fall May Need Replanting

Dormant seeding of legumes works well—when it works. But six years of research conducted at North Dakota State University is showing that there is less than a 50-50 chance of this practice succeeding in any given year, due to variability in environmental conditions.

And because of the abnormally warm weather between mid-November and mid-December, dormant-seeded grasses may not have faired much better this fall, says an NDSU researcher. So, producers who dormant seeded any acres enrolled in the Conversation Reserve Program before the beginning of November may be replanting come next spring.

"I'll almost bet the legumes are gone, and the grasses may be gone also," says Dwain Meyer, a professor of plant sciences at NDSU.

It takes alfalfa seeds from four to six days to germinate, but grass seeds take longer, anywhere from seven to 21 days depending upon species. Meyer says any newly planted CRP land south of Highway 2 and other areas where the early November snows melted are likely to have stand-establishment problems. Sandier soils with limited moisture at planting depth may be unaffected.

Meyer bases this opinion on the research he's been conducting since 1993. The research began as an effort to study fall planting dates for alfalfa, but for the last five years he's been focusing this project on dormant seeding by planting alfalfa as late as the season allows.

"In four of the six years, we have not had adequate stand establishment," Meyer says. "In two years, the seed overwintered well, germinated and emerged in early April. But subsequently, a low temperature killed the tender seedlings."

This year, Meyer planted alfalfa on Oct. 30 and Nov. 9. Based on observations, Meyer says the alfalfa planted in October has indeed germinated and those plants will die over the winter. He also believes the seeds planted in November swelled enough for death to occur.

"An alfalfa plant is not a perennial until it reaches that three- or four-leaf stage, when the first bud develops on the crown," Meyer explains. "Seedlings will survive temperatures in the upper teens, 18 F or 19 F, but single-digit temperatures will kill them."

If the legumes don't emerge along with the grasses next spring, producers with new CRP acres will need to replant the legumes, Meyer says. He recommends using a drill with double-disk openers and planting over the top of the grass stand—as early as mid-April, depending upon soil moisture, but no later than the first week of May.

Based on the data and his observations this fall, Meyer says alfalfa producers may want to forego any dormant-seeding attempts, or they should at least delay planting until early November, which in most years will be late enough to forestall seed germination. But the most consistently workable option is early spring planting.

Meyer concludes, "I personally have not seen an alfalfa stand kill out from a spring seeding."

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Source: Dwain Meyer (701) 231-8154

Editor: Dean Hulse (701) 231-6136