Evaluating Camelina sativa as a Fallow Replacement Crop in Wheat Production Systems
Camelina (Camelina sativa L. Crantz) is an oilseed crop that has the potential for fallow replacement in dryland cereal-based cropping system because of characteristics such as cold tolerance, requires fewer inputs such as fertilizer and moisture, and is early maturing. Despite its potential as an alternative bioenergy feedstock for dryland cropping systems in the Great Plains, limited research has been conducted on camelina and its agronomic potential remains largely underexploited. Field experiments were conducted starting in 2013 growing season to develop production recommendations for camelina as fallow replacement crop in dryland cropping systems in western Kansas. The first study was to determine the most productive spring and winter camelina varieties, and the best planting date to optimize production. The second study was to determine camelina yield response to nitrogen (N) and sulfur (S) application. Third study was to determine the yield impacts on winter wheat when camelina is grown in place of fallow. Our findings indicate that Blaine creek is the highest yielding camelina variety and that planting window for spring camelina in western Kansas is mid-March to the April 20, depending on soil moisture. Performance of winter camelina varieties was not consistent over the study period. Our results also showed S application had no effect on camelina seed yield. However, N application increased camelina yield but not beyond 40 lb/a. Wheat yields were unaffected by the inclusion of camelina in the rotation system. Camelina could be grown in rotation with winter wheat but there is currently no market for Kansas growers.
Camelina is being evaluated as a fallow replacement crop in wheat production systems under these set objectives: (1) determine optimum planting dates and evaluate agronomic performance of spring and winter seeded camelina germplasm (2) evaluate camelina nitrogen and sulfur fertility requirements (3) incorporating spring- or winter-planted camelina into dryland winter wheat cropping systems in the region.
Camelina Planting Date Study
Planting date effects on camelina varieties were studied at Kansas State University Agricultural Research Center near Hays, KS in 2013, 2014, and 2015 growing seasons. Three spring varieties (Blaine Creek, Shoshone, and Pronghorn) were planted at three planting dates in a split-plot design with three replications in 2013, and four replications in both 2014 and 2015. Plot dimension was 30 ft × 10 ft, and seeds were planted at 5 lb/a. Seeding date and varieties were the main plot and subplot factors respectively. Three seeding dates were selected for each year: early seeding (April 3, 2013; March 17, 2014; March 18, 2015); mid-seeding (April 16, 2013; April 1, 2014; April 1, 2015), and late seeding (April 30, 2013; April 15, 2014; April 15, 2015). Urea was broadcast applied at 50 lb N/a. Data collected includes plant height, date of flowering and physiological maturity, harvest index, seed and biomass yield. Oil and protein content were analyzed after seed harvest using Antaris II FT-NIR spectrophotometer Analyzer.
Winter camelina variety × seeding date study was carried out using three winter varieties (Joelle, Bison, and BSX-WG1). The varieties were planted at three seeding dates for each year: early seeding (October 3, 2013, October 7, 2014); mid-seeding (October 17, 2013; October 17, 2014), and late seeding (October 31, 2013; October 24, 2014). Urea was broadcast applied at 50 lb N/a in the Spring. Due to winter kill in 2014/2015 season, results will be presented for only 2013/2014 season.
Seeding date did not affect seed yield in 2013, but it had a significant effect on yields in 2014 and 2015 growing seasons. For instance, planting camelina early in March 2015 resulted in lower seed yield 220 lb/a compared to 540 and 608 lb/a when camelina was planted on April 1 and April 15, respectively. This may be due to relatively lower soil moisture availability at the time of planting in March that affected plant establishment. Seed yield differed among camelina varieties. Average seed yield across planting date was 440, 366, and 330 lb/a for Blaine creek, Pronghorn and Shoshone, respectively.
Average oil content was 27.9% across seeding dates and varieties, and was significantly different across seeding dates and varieties. At early and mid-seeding, Blaine creek had the highest oil content and was significantly different from Pronghorn and Shoshone. At late seeding, Shoshone had the highest oil content, and was significantly different from Pronghorn and Blaine creek. Protein content differed among varieties with average protein concentration of 29.9%. In 2014, protein content was different among varieties for early and mid-seeding dates. At mid and early seeding dates, Pronghorn had the highest protein content and was different from Shoshone. Blaine creek had the highest protein content and was different from the other varieties at late seeding. Early seeding in 2015 resulted in high protein content in Pronghorn and was significantly different from Shoshone. Blaine creek had the highest protein content and was significantly different from Pronghorn and Shoshone at mid- seeding date. At late seeding, protein content was high in Pronghorn and was different from the other varieties.
Winter camelina performance was not consistent. We obtained yields only in one (2014) out of two growing seasons (2013 to 2015). Averaged across two planting dates, winter camelina seed yield in 2014 were 403, 371 and 415 lb/a for BSX-WGI, Bison and Joel, respectively. Due to inclement weather conditions in 2014-2015 growing season, there was severe winterkill and none of the varieties survived the winter.
Camelina Nitrogen and Sulfur Fertility Requirements Study
This study was conducting over three growing seasons (2013, 2014, and 2015). Treatments were two S (0 and 18 lb/a) and four N application rates (0, 20, 40 and 80 lb N/a) arranged in a split-plot design with four replications in randomized complete blocks. Sulfur was the main plot factor, and N was the sub-plot factor. Urea and elemental sulfur were used as N and S sources respectively. Plot size over the three ears was 30 ft long × 10 ft wide. Spring camelina variety Blaine Creek was used for the study. Spring camelina planting was done in mid-April (April 16, 2013; April 15 in 2014 and 2015) in the three years, depending on the weather conditions in each year. Camelina was planted at 1/4 inch depth using a seed drill, at a seeding rate of 5 lb/a into wheat stubble in 2013 and 2015, and sorghum stubble in 2014. Pre-planting weed control was done using pre-emergence herbicide (Prowl H20) and glyphosate. Fertilizers were broadcast applied at emergence. Harvesting was done for each year when the crop reached maturity stage (i.e. between early to mid-July). Data collected included: stand count at maturity, plant biomass at maturity, and seed yield. Harvested seeds were analyzed for oil content using Antaris II FT-NIR spectrophotometer Analyzer. Seed nitrogen (%) was analyzed by combustion using Leco CN Analyzer. Seed N (%) was used to estimate the protein content.
Increasing N application increased camelina total biomass production with the highest biomass produced when N was applied at 80 lb/a. Average biomass production across treatments was 3166 lb/a. Sulfur application had no effect on camelina seed yield, oil and protein content over the 3-yr study. However, N application resulted in a linear increase in seed yield with maximum yield of lb/a occurring at 45 kg ha-1. Similarly, increasing N fertilizer application increased protein content but N application had no effect on oil content. Camelina seed yield varied over the 3-yr of the study. Average seed yield in 2014 and 2015 was about 759 lb/a, significantly different from average seed yield of 402 lb/a in 2013. The high precipitation in 2014 and 2015 growing seasons may have accounted for the differences in yield. Average oil content was 28% in 2013, 30% in 2014 and 27% in 2015.
Wheat-Camelina Rotation Study
The winter wheat-camelina cropping system study was established in the fall of 2013. This study had six rotation schemes, namely: wheat-fallow, wheat- winter camelina, wheat-spring camelina, wheat- grain sorghum- spring camelina, wheat-grain sorghum-fallow and continuous wheat. The treatments were arranged in a randomized complete blocks with four replicates. In order to shorten the time lapse to get results from all treatments, all phases of the rotation were present in each block, in each year of the study. Winter wheat and winter camelina were planted in October of each year, and spring camelina planting was done in mid-April. In 2015, winter camelina plots were re-seeded in February because of severe winter injury. A one-time application of phosphorous was done at 60 lbs P2O5/a at the beginning of this study. Nitrogen was applied at 60 lb/a and 40 lb/a on wheat and sorghum, and camelina respectively. Yields were harvested from 5 ft x 36 ft area using a small combine harvester. Camelina seed oil and protein content was analyzed using Antaris II FT-NIR Near-Infrared spectrophotometer Analyzer (NIRS).
Because 2014 was the establishment year, only yields for 2015 are reported. Wheat yields decreased with increasing cropping intensity, but this was not significantly different from wheat-fallow. Wheat yields were unaffected by the inclusion of camelina in the rotation system. Wheat yields ranged from 1555 lb/a for wheat-fallow (check rotation) to 1344 lb/a for wheat-sorghum-spring camelina. Sorghum yield were unaffected when grown in rotation with camelina. The general low yields were due to dry weather conditions experience in 2014 and 2015 growing season.
Camelina seed yield was affected by crop rotation. Spring camelina seed yield was 811 lb/a when camelina was planted after wheat (wheat-spring camelina rotation), greater than seed yield of 220 lb/a when planted after sorghum (wheat-sorghum-spring camelina rotation). The low yields could be attributed to inadequate soil moisture to support spring camelina establishment. Another possibility is residual herbicide injury from Atrazine, which was used for weed control in grain sorghum. In 2015, winter camelina was re-seeded in February due to winterkill. Because of the short window, there was not enough time for plants to flower and set pods before the summer heat. This led to significantly low average winter camelina yields (35 lb/a). Camelina protein content ranged from 29.5 – 30.2%, and was not significantly different among crop rotations and camelina genotypes. Nevertheless, oil content was lower in winter camelina (~21.7%) compared to spring camelina (~28.1%).
Impacts and Contributions/Outcomes
Preliminary findings were published as Extension bulletins in Kansas State University Agronomy Field Research, and Kansas Fertilizer Research Reports. Two posters were presented at the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America (ASA, CSSA, and SSSA) International Annual Meeting held in Minneapolis, MN November 6-9, 2015, and the 2016 Great Plains Soil Fertility Conference in Denver, CO. Furthermore, Dr. Augustine Obour granted field tours (to producers) and media interviews on camelina as an alternative crop for fallow replacement in dryland systems to Dryland No-Tiller E-Magazine (October 2014 issue of the Dryland No-Tiller E-Magazine).
This study was aimed at developing production recommendation for camelina production in dryland systems in western Kansas and other regions in the Great Plains with similar climatic conditions. We are still gathering more data from our camelina rotation study and this includes crop yields, water use, soil quality, and carbon sequestration. Our preliminary findings showed that the best camelina variety for dryland systems production is Blaine creek followed by Pronghorn. Optimum planting date for spring camelina is after March 15 to the second week in April. Performance of winter camelina was not consistent (yields were obtained in one out of two growing seasons) and may not be a good fit for western Kansas. Camelina will require about 40 lb N/a but S application may not be needed. Including camelina in cereal-based systems had no significant negative effect on winter wheat grain yield. However, markets will need to be developed before growers can adopt camelina in Kansas.
Assistant Professor of Soil Science
Kansas State University
KSU Agricultural Research Center-Hays
1232 240th Ave
Hays, KS 67601
Office Phone: 7856253425