Camelina: Yield and quality response to nitrogen and sulfur fertilization in Poland

Abstract

Camelina [Camelina sativa (L.) Crantz] is an ancient and underutilized crop species with various potential applications in the food and feed industries due to the high nutritional quality of its oil and high protein content. Camelina has a short life cycle, therefore it can be included in rotation systems to promote more sustainable crop production. The effects of nitrogen (N) and sulfur (S) fertilization on the morphometric parameters of spring camelina plants (cv. Omega), seed yield components, biomass yield, N fertilizer use efficiency (NFUE) and the processing suitability of seeds (crude fat content, total protein content, crude fiber content, fatty acid content and composition) were evaluated in a field experiment in Bałcyny (north-eastern Poland) in 2016–2018. The experiment had a randomized complete block design with factorial treatments, including five rates of N fertilizer (0, 40, 80, 120, 160 kg ha−1) and three rates of S fertilizer (0, 15, and 30 kg ha−1). Spring camelina plants fertilized with N produced taller, thicker and more branched shoots. The average seed yield ranged from 1.60 to 2.51 Mg ha−1. In treatments fertilized with N rates up to 120 kg ha−1, seed yield increased by approximately 61% (by 0.89 Mg ha−1), mainly due to a higher number of silicles plant−1. Seed yield increased by 4–5% (by 0.09 Mg ha−1) in response to S rates up to 30 kg ha−1. After the application of 15–30 kg S ha−1, the NFUE of N fertilizer rates higher than 40 kg ha−1 increased by 4–10% (80 kg N ha−1), 9–13% (120 kg N ha−1) and 32% (160 kg N ha−1), respectively. The proportion of camelina seeds in biomass yield (harvest index) ranged from 36 to 48%, and increased with a rise in N rate. Nitrogen decreased the crude fat content of camelina seeds by 5% and increased total fat content and crude fiber content by 9% and 36%, respectively. High N rates (160 kg ha−1) increased the protein content of seeds only in treatments fertilized with S (15 or 30 kg ha−1). Sulfur increased the crude fiber content of seeds only in treatments fertilized with N. In treatments without N fertilization, S decreased the crude fiber content of seeds. Nitrogen fertilization induced a significant increase in the proportion of PUFAs and a decrease in the proportion of MUFAs. Sulfur significantly increased the concentration of eicosanoid acid, but it had no significant effect on the proportions of the remaining fatty acids or the total content of SFAs, PUFAs and MUFAs.