Fertility and Nutrients
Camelina responds well to nitrogen
By Bruce Barker
Two research studies provide further evidence that camelina responds well to nitrogen (N) fertilizer.
By Bruce Barker
The first study by Agriculture and Agri-Food Canada (AAFC) researchers Sukhdev Malhi (now at the University of Alberta), Eric Johnson (now at the University of Saskatchewan) and colleagues looked at camelina response to N on the Prairies. Two field experiments were conducted in Saskatchewan and Alberta to determine the effect of N fertilizer application on camelina plant establishment, seed and straw yield, total N uptake in seed and straw, seed oil and protein concentration, N fertilizer use efficiency (NFUE) and per cent recovery of applied N (%NR) in seed.
Nitrogen fertilizer rates ranged from zero to 160 kilograms of N per hectare (kg N/ha) (multiply by 0.89 for lb/ac) in Experiment 1, and from zero to 200 kg N/ha in Experiment 2. In Experiment 1, fertilizer rates were not high enough to attain a maximum seed yield, however, maximum seed yields of 2013 kg/ha (36 bu/ac) were achieved at a rate of 170 kg N/ha in Experiment 2. Seed oil concentration decreased while protein concentration increased with increasing N rate.
Johnson says the yield response model indicated N response in camelina similar to that of Brassica juncea on the Canadian Prairies – growers can use soil test recommendations for Brassica juncea as a guide for camelina production. The research indicates growers should manage camelina as a high-yield, responsive oilseed crop, not as a low-input crop that was originally promoted.
“Growers on productive land may be disappointed with seed yields if they manage it as a low-input crop without applying adequate levels of fertilizer nitrogen,” Johnson says. “In saying that, some growers are trying camelina on land that is marginally productive for annual cropping, which reduces the probability of N fertilizer responses.”
The other study looked at camelina seed quality and yield traits in response to N application in Atlantic Canada. Yunfei Jiang and Claude Caldwell at Dalhousie University in Truro, N.S., led the research, along with colleague Kevin Falk at AAFC Saskatoon. They analyzed the seed oil content, oil yield, protein content, protein yield, as well as fatty acid profile relative to varying N rates and in different genotypes (varieties) under several environmental conditions. Seed samples were obtained from a two-year field study with five site-years, five genotypes, and six N rates.
The experimental strains were grown at Truro and Canning, N.S., New Glasgow, P.E.I, and Fredericton, N.B. Nitrogen was applied at zero, 25, 50, 100, 150, and 200 kg N/ha.
Camelina seed oil content, oil yield, and fatty acid profile varied by location, probably due to the effects of environmental conditions, such as aerial temperatures, precipitation, and soil composition.
Applied N increased protein content, protein yield, oil yield and polyunsaturated fatty acids (PUFA), but decreased oil content and monounsaturated fatty acids (MUFA). PUFA play a key role in brain and eye development and the prevention of heart disease. In the bio-based industrial market, a relatively high MUFA and a low PUFA content is desirable in many applications.
Oil and protein yields increased with N input because seed yield was positively associated with N rates. Saturated fatty acids did not respond consistently to applied N. Lower air temperatures during the reproductive stages increased total seed oil content, but fatty acid composition was not affected. Protein, oil, and fatty acid composition of camelina seed differed among the genotypes.
Caldwell says quality parameters are consistent across geography.