Steppuhn: Evaluating Canola and Other Crucifer Cultivars for Food and Bio-diesel Fuel Production on Saline Lands
Date: May 2012
Term: 3 years
Status: Completed
Researcher(s): Harold Steppuhn, AAFC, Swift Current, SK and K.C. Falk, AAFC Saskatoon, SK
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: n/a
Project Summary
Researchers with Agriculture and Agri-Food Canada at Swift Current, Saskatchewan conducted a three-year project to evaluate canola and other crucifer cultivars for food and bio-diesel fuel production on saline lands. Changes to funding along with dry weather in the western portions of the Canadian Prairies during 2009 resulted in some changes to the overall project. Results showed that as salinity levels increased, camelina showed greater and greater negative effects than observed with the canola in terms of seedling emergence and early survival, plant heights, relative grain yield and oil percentages. Canola varieties differ in their ability to grow in saline soils. Within the cultivars evaluated, the study results showed that InVigor 5020 plants rank as the best Crucifer cultivar for saline fields, and its production equaled or exceeded all of the other cultivars tested. Finally, the quality of the biodiesel produced from canola grown in moderately saline soil did not decrease from that produced on non-saline soil and suggest the acceptance of the expanded use of saline lands for biofuel production.
Researchers with Agriculture and Agri-Food Canada at Swift Current, Saskatchewan conducted a three-year project to evaluate canola and other crucifer cultivars for food and bio-diesel fuel production on saline lands. Changes to funding along with dry weather in the western portions of the Canadian Prairies during 2009 resulted in some changes to the overall project, which had three main goals.
I. Comparison of emergence, growth, grain yield, and oil production of camelina and canola crops grown from saline media.
Camelina is a relatively new crop to North America, and currently there is considerable interest in camelina for its potential to serve as feedstock for biodiesel fuel production in cool, semiarid climates. Researchers understand that camelina can grow and produce economically under adverse pressure gradients for water flow from soil to roots in semiarid climates, and wondered if the crop might also tolerate adverse osmotic gradients in saline root zones.
In this experiment researchers compared the inherent salinity tolerance of CS15 camelina to that of InVigor 9590 canola subjected to a full range of sulphate-based hydroponic rooting solutions from negligibly through severely saline (averaging 1.4, 3.0, 6.0, 10.0, 14.7, 19.9, and 27.0 dS m−1). Seedling emergence and early survival, plant height, growth stage, above-ground biomass, grain yield, and oil content were evaluated under the controlled environment of Canada’s Salinity Tolerance Testing Facility at Swift Current, Saskatchewan. Measurements were averaged and related to electrical conductivities of the test solutions (ECsol) for each test crop.
Overall, root-zone salinity affected both camelina and canola grain yields more than it affected seedling emergence, plant survival, seed-oil content, and oil composition. However, as salinity levels increased, the camelina was more affected than the canola in seedling emergence and early survival, plant heights, relative grain yield and oil percentages. The primary impact of this research shows a need for caution when selecting camelina for saline fields that previously produced adequate canola crops.
Table 1. Mean, oven-dried, grain yield and shoot biomass from InVigor 9590 canola and CS15 camelina crops grown in respective saline rooting media listed by average electrical conductivity.
z ECsol equals the average electrical conductivity of the test solution.
y se equals the standard error.
II. Salinity tolerance screening of Crucifer cultivars used in food oil and biodiesel fuel production.
Figure 4. Mean relative seed (grain) yield for InVigor 9590 canola and CS15 camelina crops grown in increasingly saline root zones fitted to the discount function [Eq. 2].
In this experiment, the objective of the screening was to identify the comparative salinity tolerance for the seedlings tested and to select cultivars for further testing involving crop yield functions in response to an array of root-zone salinity levels from negligible to severe. Screening was based on the sensitivity of plant tissue to root-zone salinity as measured by emergence, height growth, plant crop stage, and harvested shoot biomass. The testing facility at Swift Current can accommodate up to ten cultivars per screening set, with five sets conducted in this experiment. The oilseed crops from which the test cultivars were selected for screening included the top oil-producing cultivars of B. napus, B. juncea and other oilseed species offered by co-operating seed companies. The cultivar ‘Westar’ served as a common cultivar in each test.
Comparisons among the salinity treatments indicate that salinity tolerance differs among Crucifer cultivars, and many cultivars maintained 80% of their salinity-free (1.4 dS m-1) productivity as root-zone salinity reaches the moderate level (8 dS m-1). However, as salinity increased to 16 dS m-1, shoot production decreased in all the Crucifer cultivars tested. As salinity approached severe, only InVigor 5020, Pioneer 45H73, Pioneer 45H26, SP Banner, and BY 997 maintained 60% or more of their salinity-free productivity. (See Figure 13)
Overall, within the cultivars evaluated, the study results showed that InVigor 5020 plants rank as the best Crucifer cultivar for saline fields, and its production equaled or exceeded all of the other cultivars tested. This trait is especially valuable for canola fields with a wide range in soil salinity ranging from negligible through severe. Researchers have conducted an additional SaltLab trial applying a full range of salinity treatments (negligible thru severe) comparing the production from InVigor 5020 canola plants to Arid (B. juncea) and D5-475 (B. carinata) plants, but the final results are not yet available.
Figure 13. Average grain yield for canola in the 4th Test Group harvested 116 days after seeding and growth while subjected to root-zones solution conductivities of 1.4, 8, and 16 dS m-1.
III. Comparison of the canola feedstock quality and the resulting biodiesel fuel quality from the feedstock when produced on saline soils.
The advancing demand for biodiesel feedstock encourages Canadian producers to increase the area seeded to canola-grade oilseed crops. Salt-affected lands represent about a third of the total cultivated area across the Canadian Prairies, and present opportunities to the biodiesel industry to grow fuel crops in environments detrimental to wheat and many other crops.
The goal of this preliminary study was to evaluate canola biodiesel quality from feedstock grown in soil affected by sulphate salinity, and to obtain insight into the approximate limits in root-zone salinity associated with biodiesel fuel produced from canola grown in sulphate salt-affected soil. The specific objectives of the study were to determine percent oil recovery and the standard quality of the pure B100 biodiesel fuels derived from canola grown in soils rated as negligible, slight, moderate, and severe with respect to root-zone salinity.
Four oilseed feedstock samples from a 2007 canola field near Carmangay, Alberta representing soil root zones rated as negligibly, slightly, moderately and severely salinized were pressed to recover oil for biodiesel production. Oil recovery was favourable (within 31-36%) for all samples. Oilseed grown under conditions of the greatest salinity had the lowest oil recovery (31%). The quality of the biodiesel produced from all four oilseed samples was consistently within the ASTM International D6751-07 specifications (except for excessive free glycerol (0.058% compared to 0.02%) in the fuel produced from the negligibly-saline soil), indicating that there was no reduction in quality associated with canola feedstock grown in saline environments. This finding suggests the acceptance of the expanded use of saline lands for biofuel production.
Scientific Publications
Steppuhn, H., Falk, K.C. and Zhou, R. 2010. Emergence, height, and yield of camelina and canola grown in saline root zones. Can. J. Soil Sci. 90(1): 151-164.
Steppuhn, H., McDonald, T., Dunn, R. and Stumborg, M.A. 2010. Biodiesel fuel quality of canola feedstock grown on saline land. Biological Engineering 2(3): 165-179.