I have not used calcium nitrate, it is used in hydroponics and the farm does do hydroponics but the controller tests and meters the different components to the system from the tanks. It contains nitrogen as well as calcium salts. Too much of any salt, I would think would not be a good idea. Epsom salt contains magnesium. You will need to watch the ratio of Ca:Mg or magnesium uptake will be affected.
The magnesium cycle is very similar to the calcium cycle. Like calcium, magnesium can be contained by:
Magnesium bearing minerals
The cation exchange capacity
There are a variety of primary and secondary minerals that contain magnesium. Magnesium becomes available when these minerals dissolve, or weather. After release, magnesium is held by the cation exchange capacity of the soil particles or resides in the soil solution. Magnesium in the soil solution may precipitate into secondary minerals, be taken up by plants, or leached from the soil.
Factors determining availability
Similarly to calcium, magnesium is limited in soils that are:
Inherently low in magnesium-containing minerals
Limed with non-magnesium-containing material
Contain excessive amounts of other cations, such as potassium, calcium and ammonium, which compete with magnesium and reduces its presence on the cation exchange capacity
With a Ca: Mg ratio greater than 10:1 to 15:1, magnesium will likely be deficient.
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