indiana Prairie Farmer Logo

Sowing cover crops after wheat or another early crop opens up the window for various species.

May 6, 2019

2 Min Read
cover crops after wheat harvest
WIDE WINDOW: Seeding after wheat allowed this farmer to sow a 16-way mixture with 16 species of cover crops. Several of them must be seeded before fall crops are usually harvested. Kris Vance, NRCS

By Amanda Kautz and Don Donovan  

What is bringing farmers back to wheat? Some are adding diversity not only with a different cash crop, but also through a longer window for establishment of cover crops.

The big question for most farmers is: Should I try to double-crop soybeans, leave the field fallow, or plant a cover crop? Northern Indiana faces many challenges with double-crop soybeans. Ask this question: Will weeds or cover crops benefit you more?

Many farmers still leave wheat fields fallow. Fallow fields are an open invitation for weeds to take over. Post-wheat harvest is a time when farmers can plant cover crops — taking advantage of the remaining growing season and choosing what grows in their field, rather than dealing with whatever weeds decide to grow.

There is usually plenty of time to plant a cover crop mix that includes both warm- and cool-season species. Summer annuals such as sorghum sudangrass, sunflowers and sunn hemp build above- and belowground biomass quickly. Cool-season species such as cereal rye, radish and clover maximize root growth after frost. Overwintering species keep a living root growing in the soil until spring, feeding soil biology.

Southern options

In southern Indiana, the opportunity for extra income from double-cropping soybeans is very appealing. However, recent research indicates there is more overall value to planting a cover crop compared to double-crop beans. There are findings that corn following a cover crop after wheat has the potential of a 5- to 20-bushel-per-acre increase in yield.

Use summer annual species such as buckwheat, millet, sorghum sudangrass, sunflower and sunn hemp soon after harvest. These species tend to do well during the dry heat of late summer. If the goal is also to have a living root all winter, delay planting your cover crop until August, when cool-season cover crops can survive, or consider planting two cover crop mixes — a summer and a fall — on the field.

Species that could be included in a fall mix include oats, cereal rye, winter pea, crimson clover, daikon radish, rapeseed and hairy vetch. Some of these species will grow through the winter, building biomass and cycling nitrogen for the spring corn crop.

No matter where you’re located, consider current productivity of the field and if the field had herbicide-resistant weeds. If you have livestock, the value of additional forage might be higher than the value of double-crop beans.

When grazing cover crops, biology in the manure can help jump-start your soil biology. This jump-start will improve nutrient cycling and organic matter levels.

High-biomass, multispecies cover crop mixes planted after wheat promote diverse soil biology, which helps cycle nutrients and build organic matter and soil structure. This results in a more resilient soil and healthier crops that are able to deal with changing weather conditions and other stressors more effectively.

Kautz and Donovan are district conservationists with the Natural Resources Soil Conservation Service. They write on behalf of the Indiana Conservation Partnership.

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like