Combined Sulfur and Nitrogen Foliar Application Increases Extra Virgin Olive Oil Quantity without Affecting Its Nutritional Quality
Scientific research article - Graphical abstract
Abstract
This study investigates the effect of combined sulfur (S) and nitrogen (N) foliar fertilization on leaf S and N concentration, as well as on the growth of olive fruit and on the quantity and quality of olive oil, obtained from two olive cultivars ‘Istarska bjelica’ and ‘Leccino’ in two consecutive years. S and N are some of the most important nutrients, and both play a crucial role in plant oil production. The here-reported fertilization program significantly increased S concentration in leaves without affecting N concentration, which led to an increase in fruit yield and improvement of all fruit morphological parameters. The best oil yield per tree was obtained under the treatment with the highest S/N dose. Oil quality was not affected by S and N supply, and this allowed us to classify all our oil samples as extra virgin (EVOO). Regarding the content of total phenols (TPC) and composition of fatty acid methyl esters (FAME), they remained unaltered under the applied treatments. All investigated fruit morphological parameters, as well as fruit and oil yield, were highly cultivar-dependent. ‘Istarska bjelica’ was characterized as a cultivar with higher fruit mass and pulp percentage, while its stone parameters were lower than those of ‘Leccino’. Consequently, the extraction oil yield obtained from ‘Istarska bjelica’ fruits was much higher. Moreover, environmental conditions had a great impact on fruit and oil quantity. The here-obtained results led us to the conclusion that supply of S and N can enhance oil production without affecting its nutritional quality, a finding that could generate large long-term effects on economic growth in the olive oil sector.
Behind the story....
I always prefer visual storytelling compared to barren text. Somehow, one without the other for me were not possible even when I was younger. When I can draw it - I can understand it. The visualization helps me to present my thoughts when words can not be found. I have used illustrations before, but never for a scientific paper. As I started to take part in the scientific writing process, I began illustrating in a different manner. The stakes were different. The workflow changed. The goal was to use the DataViz to indicate the results differently, in a manner not applicable in the written form of the paper. The result is this graphical abstract - a combination of my own drawings and the icons available at the Biorender library. Even if I prefer drawing everything myself, I'm in a period of life when "things need to be done" and sometimes I use such shortcuts. I hope you enjoy them - both the graphical and paper!
