July 3, 2019
Purdue agronomists offer prevent plant option recommendations
WEST LAFAYETTE, Ind. – Farmers who weren’t able to plant because of flooding and excess rainfall this spring will benefit from the recent announcement by the USDA’s Risk Management Agency (RMA), who recently changed the haying and grazing date restriction for prevented planting acres.
This announcement enables farmers who plant cover crops on prevented plant acres to hay, graze, ensile, or chop those fields earlier than November 1. For 2019, RMA will allow farmers to make forage on prevent plant acres after Sept. 1.
Keith Johnson, professor of agronomy, said some producers with prevent plant acres are considering using corn or soybeans as a cover crop, a practice recently approved and supported by the Extension Field Crop and Natural Resources Conservation Service (NRCS) Specialists.
“Farmers recognize that corn and soybeans have positive characteristics as a cover crop, since both crops can canopy quickly, reduce soil erosion, and scavenge nutrients,” Johnson said.
The late planting date includes additional agronomic recommendations for this 2019 forage harvest. Tony Vyn, professor of agronomy, said that even with the expectation of normal weather conditions for summer and fall, adapted corn hybrids might not reach one-half milk line (a crucial stage of development) 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 explained. “Silage made too wet will result in seepage and poor quality” he added.
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.
Using short-season hybrids for a given region is recommended. However, Purdue Plant Pathologist Darcy Telenko explains short-season hybrids, especially 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. Also, remember seeding rates should not be increased if the ultimate goal is forage, and stored grain with GMO traits cannot be used a cheaper alternative seed source,” Telenko said.
“It’s also a good idea check with your seed dealer to see if the GMO traited seed corn you plan to plant is approved as a cover crop. From the standpoint of early canopy closure, 15” rows are preferred over 30” she added.
Extension 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 said.
“Full season soybean varieties, for a given region, are preferred since they will produce more vegetative biomass and delay pod development and seed fill. Vegetative biomass is usually maximized halfway between R5 and R6 growth stages, though seed viability in the older pods and 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,” he explained.
“Producers should consider the long-term rotation of a given field and evaluate the positives and negatives for choosing either of these two crops,” said Casteel.
He encourages farmers to ask questions like, ‘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 ramification for the present and the future, including researching e better cover crop species available that will help break up a corn or soybean cycle for at least one year.
“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 carry-over impact on cover crop germination, and select cover crop species to be planted accordingly,” he encouraged.
Greg Bossaer, assistant program leader for agriculture and natural resources, Purdue Extension urged farmers to keep Crops Insurance Agents informed and get final approval for prevent plant, cover crop plans.
“Additional information on cover crop species for prevent plant acres are available, so we urge growers to consult with their local ANR Extension Educator or NRCS personnel,” Bossaer added.
Media contact: Jesica Hollinger, 765-496-0108, jehollin@purdue.edu
Source: Keith Johnson, 765-494-4800, johnsonk@purdue.edu
Agricultural Communications: 765-494-8415;
Maureen Manier, Department Head, mmanier@purdue.edu
