Here is a question Brian Frieden received recently once news spread that USDA’s Risk Management Agency would allow planting of corn or soybeans as cover crops on prevented planting acres. Frieden is regional director for RMA, based in Springfield, Ill., and covering Illinois, Indiana, Michigan and Ohio.

Question: Can I plant a cover crop of the same crop I was prevented from planting? Or in other words, can I use the seed I have on hand (corn, soybeans, wheat) to plant a cover crop as long as it’s at a lower seeded rate that qualifies for cover crops?

Frieden: “Yes. An acceptable cover crop must be generally recognized by agricultural experts as agronomically sound for the area for erosion control or other purposes related to conservation or soil improvement [if it] is planted at the recommended seeding rate, etc. The cover crop may be the same crop prevented from planting and may still retain eligibility for a prevented planting payment. The cover crop planted cannot be used for harvest as seed or grain.”

Here is an example: A producer plants a cover crop of corn for silage to be cut after Sept. 1 following a prevented planting crop of corn for grain. If all other provisions are met — and planting corn for silage at rates consistent with a cover crop is generally recognized by agricultural experts as being agronomically sound for the area for erosion control or other purposes related to conservation or soil improvement — it would not impact the prevented planting payment.

Agronomic considerations

Purdue University Extension agronomists have weighed in on matters related to using corn or soybeans as cover crops on prevented-planting acres. Here are some highlights:

Late-planting implications for corn. The late planting date includes additional agronomic recommendations for this 2019 forage harvest. Tony Vyn, professor of agronomy, says that even with the expectation of normal weather conditions for summer and fall, adapted corn hybrids might not reach one-half milk line before a killing frost occurs. 

“A one-half milk line in the kernels during the grain-filling stage corresponds with a whole-plant moisture content essential for proper ensiling through lactic acid-based fermentation,” Vyn explains. “Silage made too wet will result in seepage and poor quality.”

Green-chopping the standing corn is also an option, but daily harvest is required to have day-to-day uniformity of the ration being fed to livestock. Wet soil conditions can interrupt the process.

Disease implications. Using short-season hybrids for a given region is recommended. However, plant pathologist Darcy Telenko explains that short-season hybrids, especially when planted late, have a risk of higher levels of infection from foliar disease, so scouting for disease throughout the growing season is important.

“It’s important not to fertilize, especially nitrogen,” she says. “Also, remember seeding rates should not be increased if the goal is forage, and stored grain with GMO traits cannot be used as a cheaper alternative seed source.”

Traited seed. “It’s also a good idea to check with your seed dealer to see if the GMO-traited seed corn you plan to plant is approved as a cover crop,” Telenko says. From the standpoint of early canopy closure, 15-inch rows are preferred over 30-inch, she adds.

Soybean seed for cover. Soybean specialist Shaun Casteel reminds farmers that treated soybean seed that cannot be returned to the seed dealer is a suitable cover crop source after checking to make sure the GMO-traited seed soybean varieties are approved for cover crops. 

“Farm-stored, treated soybean seed saved for 2020 planting will have reductions in germination potential, as well as a loss in seed treatment efficacy,” Casteel says.  

“Full-season soybean varieties, for a given region, are preferred since they will produce more vegetative biomass and delay pod development and seed fill,” he says. “Vegetative biomass is usually maximized halfway between R5 and R6 growth stages, though seed viability in the older pods will likely begin at the point when harvested before leaf yellowing — with the approximate growth stage of R7, when the soybean is a viable forage source.”

Long-term rotation effects. “Producers should consider the long-term rotation of a given field, and evaluate the positives and negatives for choosing either of these two crops,” Casteel says.

He encourages farmers to ask questions such as, “Do I have soybean cyst nematode? If so, am I planting a variety that will help reduce the population?” It’s also important to keep in mind that some cover crop species may help reduce the SCN population. Casteel prompts farmers to make future considerations as well, including how the corn or beans planted will result in additional disease pressure in future years.  

“Farmers need to think and consider ramifications for the present and the future, including researching better cover crop species available that will help break up a corn or soybean cycle for at least one year,” he says.

“Be sure to check seed and seed treatment labels to ensure that the seed source is approved for forage production, and also be aware that previously applied herbicides can have a potential carryover impact on cover crop germination, and select cover crop species to be planted accordingly,” he says.