Influence of nitrogen and sulfur application on camelina performance under dryland conditions

• We evaluated nitrogen and sulfur effects on camelina.
• Nitrogen requirement of camelina depended on rainfall amount and seeding date.
• Nitrogen increased camelina yield and estimated biodiesel.
• When planted early, nitrogen reduced camelina oil content.
• When planted late, nitrogen had no effect on camelina oil content.

There has been recent interest in camelina (Camelina sativa L.) because of its potential as a low-cost feedstock for biofuels and hence the need to optimize its production. We hypothesized that nutrient requirements under dryland environments with low and highly variable precipitation will depend on year and timely seeding. This study aimed at determining (a) the effects of nitrogen (N) and sulfur (S) application on the growth, yield, seed protein and oil content of spring-type camelina for the environmental conditions of northern Wyoming, USA, and (b) N and S requirement when camelina is seeded late. Four N levels (0, 28, 56, and 112 kg ha−1) and two S levels (0 and 25 kg ha−1) were studied. Sulfur had no significant effects on the measured responses. For trials established on May 13, 2013 and April 11, 2014, there was a general increase in plant height, seed yield, protein content, and protein yield with N application. Nitrogen application resulted in 31% seed yield increase but decreased oil content by 2.7% relative to the unfertilized control. As such, biodiesel that could be produced increased with N application. When seeded in May 24, 2014, N application caused a significant increase in the plant height, seed yield, harvest index and estimated biodiesel, but had no effect on the oil and protein content. The application of N showed a quadratic response to seed yield in all the trials. In general, applying N rate beyond 56 kg ha−1 did not result in significant increase in seed yield for trials established in May 13, 2013 and April 11, 2014, and 28 kg ha−1 for the trial established in May 24, 2014.