Reintroducing Flax (Linum usitatissimum L.) to the Mediterranean Basin: The Importance of Nitrogen Fertilization

Abstract

An increasing interest has been reported regarding the reintroduction of flax in the Mediterranean region. The aim of this present study was to evaluate the effects of nitrogen (N) fertilization on the performance of flax cv. Everest, under Mediterranean climate conditions. A two-year study was carried out in 2018–2019, in Western Greece. The experiment was set-up in a randomized complete block design with four replications and six treatments of different N fertilization rates (0, 20, 30, 40, 50, and 60 kg N ha−1). Measurements included plant biomass, the leaf area index (LAI), the yield, and the Growth Degree Days (GDDs) required for full seed maturity. The N uptake of flax was also evaluated utilizing the Nitrogen Harvesting (NHI) and Nitrogen Utilization Efficiency (NUtE) indices. Although the highest fertilization rate (60N) increased the yield by 35.4% (2018) and 23.1% (2019), a GDDs and N indices assessment revealed that it noted the lowest efficiency and may lead to significant yield losses, as it significantly prolonged the crop cycle. On the contrary, even though fertilization rates of 20 and 30 kg N ha−1 increased the yield only by 7% and 15% (on average), they were more efficient, and prolonged the crop cycle less (compared to 60N).

Phytoextraction Potential of Flax Grown on Multimetal Contaminated Soils: A Field Experiment

“…[6], in pot experiment that conducted with three different level of cadmium, nickel, lead and antimony in three flax cultivars, concluded that as the dose of the metal and antimony increased, the growth characteristics of the varieties decreased. The mean values of the height recorded in our study align with those reported in other field non-polluted experimental studies, resulting similar average height values for flaxseed [25,27,37]. [25] highlighted the aspect of the growing cycle duration, reporting taller linseed plants (62.9 cm) during autumn sowings compared to spring sowings (55.5 cm) in a semi-arid Mediterranean environment.…”

“…These results are in accordance with the results of this paper. In contrast to previous investigations that established a linear correlation between nitrogen levels and height in flaxseed [37][38][39][40], our results at the spring cultivation vary, giving no significant differences between treated and control plants, while winter cultivation results were in accordance with the findings of the other researchers.…”

“…The main factors that affect the biomass productivity of flax are nitrogen fertilization, climatic conditions, and water availability especially during the flowering and seed filling stage and elevated concentration of heavy metals and metalloids [6][7][8]10]. Nitrogen fertilizer plays a crucial role in promoting plant growth and productivity across various crops, with studies suggesting increased nitrogen levels lead to elevated biomass [37,38,41,42], although excessive nitrogen application, may reduce total dry matter in flaxseed [10,43]. Climatic conditions, especially wet and cold soil in spring, negatively impact flax yield by blocking plant emergence [8,28].…”

First steps toward developing Lewis flax (Linum lewisii Pursh) as an agronomic crop

“…Results are reported in Table 1. Fertilizer recommendations for Lewis flax do not exist, however previous research about annual flax indicated that the optimal balance between yield and N use efficiency was found between 20 and 30 kg ha −1 N (Kakabouki et al, 2021), or approximately the amount of N residual our fields contained. Therefore, we did not add supplemental fertility to either field site during data collection.…”

Biological Response of Quinoa Plants to Various Nitrogen Levels and Priming Techniques

“…Soil treatment with N at the rate of 75 kg N per hectare increased levels, promoting both growth and yield parameters. An increase in biomass, harvest index, and economic yield was observed (Kakabouki et al, 2021).…”