We haven't done a whole lot in this area and sometimes it is fun to look at things in this light. There are over 18,000 plants that are known to produce essential oils or have theses oils in them. Only about 400 or so are known to be used for essential oil production to be used for therapeutic applications and for nutritional food flavorings. So with that lets look at several minerals and how they affect essential oil production n a few selected plants that are used for essential oil production. This same idea also applies to actual food production as well.
1st. Mineral; Cobalt. Cobalt is a very important micro-nutrient mineral. The ideal PPM in humans is best at 8 PPM.
With Rosemary; Rosemary was measured in some studies. With Cobalt being available at 10 PPM for plant uptake and at a soil pH of 8.49 gave the best Rosemary overall. This one aspect with the pH is why Rosemary does so well and why we select Rosemary from high alkaline soil conditions. In the other oils that will be mentioned, they all do much better in soils that are slightly acidic. In fact some of them won't grow in the high pH soils, as Rosemary does. In the one set of really good studies, they cut Rosemary 3 times through out the growing season. The 3rd. cutting produced the highest amount of oil. In the control soil, at 1 PPM of Cobalt, the first cutting produced .12 ml per plant, .13 ml. per plant, on second cutting and the 3rd. cutting produced .74 ml per plant. At the 10 PPM level the 1st cutting produced .26 ml per plant, 2nd. cutting 2.31 ml per plant and 4.69 ml. per plant. At 15 PPM the 1st cutting produced .22 ml. per plant, 2nd. cutting at 1.78 ml. per plant and 3.66 ml. per plant. Overall production, per H/Ac, the control produced 31.7 Liters. The 10 PPM produced 122.46 Liters per H/Ac. The 15 PPM produced 78.94 Liters per H/Ac. The 10 PPM level also gave the best overall chemical profile, as we like to see for aromatherapy purposes, as well.
With Basil; Basil gave the best production of 49 Liters per H/AC when the Cobalt was at 30 PPM. The Basil control in this study was at 15 PPM and it gave 38 Liters per H/AC. One of the key elements in Basil, Linalool, was the highest at the 15 PPM of Cobalt and the other end of the scale of Basil with the Menthyl Chavecol at the 30 PPM level. Also of note the Eugenol, a key pain killing chemical in Basil, was best at the 30 PPM Cobalt level. However, from an overall perspective, Basil at the 15 PPM resulted in the best overall quality of the chemical constituents and nutritional status of Sweet Basil. The 15 PPM level also produced the best synergistic effect among the various chemicals normally found in Sweet Basil. This also includes the Hormone levels and enzymes.
With peppermint; Peppermint studies also showed best overall quality and production as it relates to the Cobalt influence at the 15 PPM level. Some of the notable values were among the Magnesium, Zn, and Cu levels. The Peppermint production levels were at 19 Liters per H/Ac. 15 PPM gave 39 Liters per H/Ac. and at the 30 PPM level the Peppermint only produced 26 Liters per H/Ac.
With Coriander; Coriander did best among the values of the minerals at the 12.5 PPM level as to Cobalt. However the Iron was not as high at the 12.5 PPM level as with other levels. But on the other hand, when the Cobalt level was raised to a slightly higher level of Cobalt, the production volume increased by 44% over the 12.5 PPM level. Coriander is known for it's high Cobalt uptake capacity. However, Coriander is an oil that does not necessarily improve in values as the production level increases as it does in many other oils. Always an exception to the rule I guess.
With Dill; Dill oil does somewhat better with a slightly lower Cobalt level. Overall Dill does a little better at the 10 PPM levels than it does higher or lower levels. But it will do better at a 15 PPM level than it does at the 5 PPM level. For example, in a study the control only produced 2.22 ml per plant. At the 5 PPM concentration it produced 2.83 ml. per plant. At the10 PPM level it was at 7.58 ml. per plant and at the 15 PPM level it was at 6.27 ml. per plant. So as you can see with Dill, by moving the Cobalt concentration up a little past the idea of 10 PPM Cobalt for Dill does not diminish the production amount or quality as much as if you move the Cobalt concentration downward.
*** As to the control reference. Usually the control is just the typical, or in this application is referencing the sample plot in the field that received no treatment, just "as is". The experiment, the PPM means that those experimental plots have had the component being studied, has had the PPM listed brought up to the concentration listed PPM listed. In these studies I did not observe any statement as to what the control level was before any component has been added. Also, keep in mind that not all of the associated nutrients are not listed and looked at very extensively. No mineral works alone, but in these studies, only one is looked at so as to study its individual effect. However, sometimes a note is made of the various other elements in the entourage of the studied component and how they are affected on the whole.
Summary; Perhaps the most important thing about the Cobalt effect on Aromatic type plants, well all forms of life, is the ability for Cobalt to influence Photosynthesis and the Photosynthesis and Vitamin B-12 connection. This is a huge and vitally important factor. Also the Cobalt has a big influence on the water flow to the plant's root system. As it gives for better water flow to the root system. Specifically, it maintains a positive water flow to the roots. Tomatoes do much better when there is a proper Cobalt concentration in the water given to Tomatoes. From all of these studies, it appears to indicate, with a few exceptions, the best soil Cobalt concentrations are at about the 15 PPM levels in the soil and 8 PPM for humans. An interesting note was that in several studies it was discovered that in newly reclaimed soils, the plants did best at the 7.50 PPM concentration. As the soils become developed then the higher levels are indicated.
I was going to cover several other minerals and their effect on aromatic plants, but this is sufficiently long enough for one discussion. The next one will cover Nitrogen. So now you know a thing or two that has a profound effect on essential oil production and essential oil quality. So next time one of these freaks start coming down on you about essential oil quality and that they have the best oils and they can prove it, just ask them about some of this stuff. You will get a laugh out of the change of demeanor, going from a "know it all", "to a deer in the head light" look. Bu at that point you need to walk away as these type of psychopaths will always come up with something out of left field to change the narrative. I want to do more of these types as they are fun to learn type of things. Until next time, take care. KK.
End of Discussion.