Camelina growth and yield response to sowing depth and rate in the northern Corn Belt USA

Authors: Gesch, Russell - Russ; Matthees, Heather; Forcella, Frank

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/27/2016
Publication Date: 1/1/2017
Publication URL: http://handle.nal.usda.gov/10113/63330
Citation: Gesch, R.W., Dose, H.L., Forcella, F. 2017. Camelina growth and yield response to sowing depth and rate in the northern Corn Belt USA. Industrial Crops and Products. 95:416-421.

Interpretive Summary: Camelina is a new oilseed crop for the U.S. that is gaining popularity as a feedstock for biofuels and as heart-healthy cooking oil that is high in omega-3 fatty acid. Because camelina is a new crop and therefore, new to farmers, there is still a great need for developing best management practices for its production in order to improve its seed and seed oil yields. Previous research conducted by others has shown that planting and establishing a good camelina crop (i.e., adequate plant population in the field) can be difficult in some environments. One of the reasons for this seems to be related to current recommendations for planting the seeds at a shallow depth in the soil. Shallow-planted seeds are exposed to extremes in temperature and moisture, which are factors that greatly affect whether the seeds germinate and emerge from the soil or not. Seeds planted deeper in the soil are more protected from exposed to temperature and moisture extremes. However, current recommendations in several university extension-based grower guide bulletins for camelina suggest plating camelina at about a quarter inch in the soil. A field study was conducted at the Swan Lake Research Farm near Morris, Minnesota, to determine best planting depth and rate for spring camelina. It was discovered that camelina could be planted at up to about 1 inch deep without significantly reducing crop establishment or its seed and oil yield. We also found that because camelina seeds are so vigorous, they can be planted at relatively low seeding rates, which will help save farmers money by potentially not having to plant as much seed as previously recommended. The results of this study will help improve recommendations made to growers interested in producing camelina. Being able to plant camelina deeper is also good news for growers who farm on soils and in climates where the top quartaer to half inch soil may be prone to large temperature and moisture fluctuations. These results will also benefit other researchers working on camelina, as well as crop consultants, and the specialty seed industry.

Technical Abstract: Camelina (Camelina sativa L.) is gaining interest as a productive alternative oilseed crop for biofuels and healthy food-use applications. Developing sound agronomic practices for its production is key to optimizing its seed oil yield potential. Plant stand establishment of camelina has been problematic in some environments, which may be related to its small seed size and current recommendation for shallow sowing. Shallow sowing can diminish seed to soil contact and expose seeds to large soil temperature and moisture fluctuations, which greatly affect germination and seedling emergence. A study was conducted in 2011 and 2012 on a Barnes loam soil in western Minnesota to examine the effects of sowing spring camelina at soil depths of 1, 2, and 4 cm at sowing rates of 2, 3, and 6 kg ha-1. Seedling emergence increased with sowing rate, but averaged across sowing depths it had no effect on seed yield. There was little difference in seedling emergence between the 1 and 2 cm sowing depths and no difference in seed yield. However, averaged across sowing rates, sowing at 4 cm led to a 67% stand reduction and a significant 23% loss of yield compared with the 1 and 2 cm depths. Neither sowing depth nor rate affected seed oil content or harvest index. Results show that camelina has exceptional yield compensation capacity at low plant densities and can be sown deeper than commonly recommended without sacrificing yield. Deep sowing may be beneficial for certain soils prone to large temperature and moisture fluctuations.