Is winter camelina a cover crop species for the Midsouth?
The positive effects from using cover crops [CC] in a crop production system are well-documented. Click here to access a CC White Paper that summarizes those advantages, and here to access results from CC variety trials that were conducted in the southern U.S.
Many of the advantages from using CC’s accrue from using the proper species of CC–i.e. not all CC species provide all of the benefits that can accrue from using a CC. For example, CC’s can be used to 1) reduce or prevent soil compaction [brassicas such as tillage radish], 2) scavenge nitrogen [N] that is not used by the preceding cash crop [cereals such as cereal rye and triticale], 3) provide biomass in an amount that will prevent or reduce weed emergence [cereals], 4) provide soil cover that will prevent or reduce erosion in the off-season [fast-growing CC species], and 5) provide residue with an N content [legumes] that will benefit a following grain crop.
According to a USDA-NRCS Fact Sheet titled Winter Camelina, camelina is a winter-hardy brassica that can be used as a CC to fight soil compaction and scavenge excess N and P not used by a previous crop. Other pertinent points in this publication about this species are 1) information about planting, 2) C:N ratio of plant material, 3) performance ratings for traits such as N scavenging and compaction fighting, and 4) allelopathic effect on weed germination.
A recent article titled Winter camelina emerges as promising alternative to rye cover crop presents information about using this species as a CC in a soybean production system in Wisconsin. However, according to a report from the Univ. of Florida titled Camelina production in Florida, this plant species has a wide range of adaptability that will allow it to be grown successfully in the southern U.S. Thus, the following points should be considered if Midsouth soybean producers use camelina as a CC.
• Only a few improved varieties of camelina are available because of limited breeding efforts with the species.
• In the southern U.S., camelina should be planted by mid-November.
• Since there is limited knowledge about herbicides for camelina, it is essential that varieties of this species be planted in a weed-free seedbed.
• Little is known about the impacts of residual herbicides that may have been applied to a preceding crop. Current dogma suggests that the same restrictions on use of residual herbicides for canola by followed for camelina.
• Volunteer camelina plants will not present a problem in subsequent crops.
• Camelina can be grown and harvested as an oilseed crop that is used for a biofuel feedstock.
A publication titled Winter Camelina from the Forever Green Initiative provides the following information.
• Winter camelina is a winter hardy cash cover crop that can provide both ecosystem services and economic benefits to cash crop farmers.
• Winter camelina can be sown after harvesting corn and/or soybeans to provide overwintering soil cover.
• This CC species can scavenge N and P from the soil, thus reducing the potential for their contamination of surface and ground waters.
• A link to a Winter Camelina Grower’s Guide is provided.
Click Interseeding camelina and rye in soybean with varying maturity provides soil cover without affecting soybean yield for an article about using camelina as a CC in soybean.
Composed by Larry G. Heatherly, Sept. 2025, larryh91746@gmail.com