By Curt Reese1, Yuzhi Li1, Russ Gesch2, and Frank Forcella3
Winter camelina, a relatively new oilseed, could become an important crop in our local area, as well as in the entire upper Midwest. Seeded in the fall, it can be used as a cover crop. During early spring, plants grow rapidly and protect against soil erosion. Camelina matures quickly and can be harvested by late June, thereby allowing for double- or relay-cropping with soybeans Winter camelina has potential for organic production because it requires little fertilizer and can suppress weed growth.
Camelina seeds contain about 40% oil, and 30-40% of that oil is comprised of an essential omega-3 fatty acid that is beneficial for heart health. Seed meal of camelina following oil extraction can be used to feed livestock, including pigs. Most organic swine producers grow their own feed crops to reduce costs because the price of organic corn and soybean meal is about two to three times higher than non-organic meal. However, growing winter camelina organically has never been explored. A research project is being conducted at the West Central Research and Outreach Center (WCROC), Morris, to evaluate integrating winter camelina into organic swine production.
Winter camelina was seeded on Oct 1st, 2018 on 20 acres of organic-certified land at the WCROC. Among the 20 acres, 11 acres were used for a single crop of camelina and another 9 acres were used for relay cropping with soybean. Row spacing was 6 inches for the camelina in the monocrop field, with a seeding rate of 7 lb per acre. In the relay cropping field, camelina was seeded the same way except that a row was skipped every 30 inches, with a seeding rate of 5 lb per acre. Camelina geminated on Oct 18, 2018, 17 days after seeding and emerged before the first snowfall. On June 3, 2019, soybean were seeded at 180,000 seeds per acre in the 30-inch skip rows in the relay cropping field.
Camelina was harvested on July 13, 2019 using a combine in both the single and relay cropping field. At harvest, soybeans in the relay cropping field were in the 4-leaf stage. During harvest, camelina was cut about 8 inches above the ground in the monocrop field and about 12 inches above the ground in the relay cropping field to avoid cutting the soybeans. The difference in cutting height between the monocrop and relay cropping field may be associated with low yield of camelina in the relay crop field because camelina seed pods between 8 and 12 inches were not harvested. Camelina yield was 1404 lb per acre in the monocrop field and 689 lb per acre in the relay crop field, with 25% moisture content. The cool wet spring and summer resulted in a later harvest date and higher moisture content than we targeted. We also had a very short harvest window because of the rain during this time. In general, yield of organic camelina is comparable to yield of conventional camelina which is about 800 to 1200 lb per acre.
Soybean in the relay crop field was harvested on November 26, 2019. This late harvest date was because soils were too wet to support the combine. Yield of soybean in the relay crop field was 18 bu per acre, which was about 1/3 to half the yield of organic soybean in monocrop systems. The camelina suppressed weeds in the soybean field up to maturity. However, after camelina harvest, weeds grew quickly through the open canopy and competed with the soybeans. Cultivation was not used in this study, but could have been a way to control late-season weeds in the relay system. In addition to relaying a short season crop like soybean, a forage crop could be grown instead. Swathing could also be used to help desiccate the camelina earlier and then one could potentially plant soybeans afterwards. Much more research can be done on this system, and there is good potential to increase the profitability and overall production per acre.
Take home message: 1). Yield and composition of camelina grown organically was similar to what reported for conventional camelina. 2). Growing camelina organically in a relay cropping system can potentially increase total yield of organic land. 3). Harvesting and weed control of the second crop in a relay cropping system and drying camelina remain a challenge to organic camelina production. Currently, we are replacing 10% of organic corn and soybean meal with the camelina press cake in an organic pig trial at the WCROC. The pigs appear to tolerate this ration.
This project is supported by Organic Transition Program (Award# 2017-51106-27129) from the USDA National Institute of Food and Agriculture.
1West Central Research and Outreach Center, University of Minnesota, Morris, MN
2USDA-ARS North Central Soil Conservation Research Lab, Morris, MN
3Agronomy & Plant Genetics Department, University of Minnesota