Nitrogen requirements of Ethiopian mustard for biofuel feedstock in South Dakota

Authors: ALBERT, PHILLIP - South Dakota State University; Osborne, Shannon; MATHEW, FEBINA - South Dakota State University; ALI, SHAKAUT - South Dakota State University; SIEVERDING, HEIDI - South Dakota State University; KUMAR, SANDEEP - South Dakota State University; NLEYA, THANDIWE - South Dakota State University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2019
Publication Date: 3/8/2019
Citation: Albert, P., Osborne, S.L., Mathew, F., Ali, S., Sieverding, H., Kumar, S., Nleya, T. 2019. Nitrogen requirements of Ethiopian mustard for biofuel feedstock in South Dakota. Agronomy Journal. 111:1304-1311.

Interpretive Summary: Ethiopian mustard (Brassica carinata) a non-food oilseed crop has received a lot of attention for its potential as a low-input biofuel feedstock suitable for production in the semi-arid regions of the Northern Great Plains. As a new crop to region, best management practices have yet to be developed. The research objective was to evaluate the effects of nitrogen fertilizer rate on seed yield, seed oil concentration and oil yield, and to determine the economic optimum N fertilizer rates. Research was conducted at two locations in South Dakota to evaluate the response of two B. carinata varieties to five nitrogen fertilizer rates (0, 28, 56, 84 and 140 kg N ha-1) during 2015 and 2016 growing seasons. Seed yield and oil yield reached a peak 84 kg ha-1 N and then slowly decreased with additional nitrogen applied, but seed oil concentration decreased as nitrogen rate increased. The economic optimum nitrogen rate ranged from 64.5 kg ha-1 to 81 kg ha-1 depending on fertilizer cost and seed price. These results show that the nitrogen requirement for B. carinata is lower than that for many crops grown in the NGP including corn and small grains. These findings confirm that B. carinata is a low-input crop with a potential for incorporation into cropping systems in the semi-arid regions of the NGP.

Technical Abstract: Ethiopian mustard (Brassica carinata) is a non-food oilseed crop that has received a lot of attention for its potential as a low-input biofuel feedstock suitable for production in the semi-arid regions of the Northern Great Plains (NGP). As B. carinata is a new crop to the NGP, the best management practices have yet to be developed. The objective of the study was to evaluate the effects of nitrogen (N) fertilizer rate on seed yield, seed oil concentration and oil yield of B. carinata and determine the economic optimum N fertilizer rates. Field studies were conducted at two locations in South Dakota to evaluate the response of two B. carinata varieties to five N fertilizer rates (0, 28, 56, 84 and 140 kg N ha-1) during 2015 and 2016 growing seasons. Increasing N fertilizer rate increased seed yield and oil yield each reaching a peak 84 kg ha-1 N and then slowly decreasing following a quadratic model. On the other hand, increasing N rate linearly decreased seed oil concentration. The economic optimum N rate ranged from a low of 64.5 kg ha-1 to a high of 81 kg ha-1 depending on cost of N fertilizer and the price of carinata seed. These results show that N requirement for B. carinata is lower than that for many crops grown in the NGP including corn and small grains. These findings confirm that B. carinata is a low-input crop with a potential for incorporation into cropping systems in the semi-arid regions of the NGP.