Grain yield and quality response of flaxseed to chemical, biological and organic fertilizer

In spite of its economic value and various medicinal effects, flax (Linum usitatissimum L.) has been classified as a neglected crop during recent years. Therefore, it is necessary to improve grain yield and product quality indices along with reduced amounts of chemical inputs. In comparison with the control treatment (no fertilizer), application of chemical nitrogen increased flax grain and oil yield, respectively, by as much as 37% and 21%. There are several reports covering the grain yield increment of different crops influenced by organic fertilizers (Kumar et al., 2009; Sajadi Nik et al., 2011). As Mohanty et al. (2006) have reported, the phosphorus content in groundnut seed and phosphorus uptake in the whole plant have improved more under vermicompost treatment as compared to chemical fertilizer. Pirzad et al. (2013) reported that Fe foliar application increased the grain and essence yield of Anise (pimpinella anisum L.). Investigation of the possible reduction in chemical fertilizer application in flax production, and studying the plant response to integrated nutrition, were considered as the main objectives of the current study.
In order to study the effect of organic, chemical, biological and integrated nutrition systems on grain yield and quality of flax (Linum usitatissimum L.), a field experiment was conducted at the research field of Tarbiat Modares University (located on the Tehran-Karaj freeway, 16 km West of Tehran) during spring and summer 2013. The experiment was carried out as randomized complete block design with three replications. The treatments consisted of a control (no fertilizer), providing all nitrogen requirement from a chemical source (urea), from biological source (nitroxin), from an organic source (vermicompost), integrative nutrition 1 (urea nitroxin), integrative nutrition 2 (vermicompost urea), supplementary chemical nutrition (urea 緫殊娧 combi 2 micronutrient) and integrative supplementary nutrition (nitroxin urea fetrilon combi 2 micronutrient).
The results of analysis of variance indicated there were significant effects of nutritional systems on almost all traits such as grain yield, biomass, number of capsule per plant, number of branches, capsule weight per plant, 1000 seed weight, leaf dry weight, oil yield, oleic acid and linolenic acid (omega 3) content. The highest grain yield (703.08 kg. ha-1) was obtained under the chemical nutrition system, followed by the integrated (50% vermicompost % urea) and supplementary integrative nutrition systems (nitroxin urea 緫殊娧 combi2). Overall, these results suggest that the application of supplementary integrative nutrition increased flax grain yield and improved quality (13.05 % linoleic acid and 47.28% linilenic acid ) of flaxseed oil (65.7% compare to control). This treatment produced the highest oil yield (271.9 kg ha-1).
According to the findings of this research, integrative nutrition (nitroxin urea fetrilon combi 2 micronutrient) could be introduced as a good alternative for conventional methods of soil fertilization and will be considered as a forward step towards the goals of sustainable agriculture.