Very low PK fertilizers. (K-lite)

[DavidCampen]

Actually, I have decided that the NPK of a blended fertilizer is not very usefull and in fact misleading since it ignores calcium and magnesium which are at least as important as nitrogen, phosphorous and potassium.

I think that one can blend a good fertilizer using only calcium ammonium nitrate (YaraLiva Calcinit), magnesium nitrate (Magnisal) and potassium dihydrogen phosphate (MKP).

First determine the ratio of calcium ammonium nitrate to magnesium nitrate that will give you your desired ratio of calcium to magnesium. This also determines the percentage of nitrogen. For example, a 2:1 ratio of calcium ammonium nitrate to magnesium nitrate gives you 4:1 calcium to magnesium ratio and an NPK of 14-0-0 (12.7% Ca, 3.2% Mg). Then add MKP to get the desired amount of phosphorous and potassium. For example, 2:1:0.25
blend of Calcinit, Magnisal and MKP gives:
NPK 13-4-2.7 (11.7% Ca, 3% Mg).

[tucker85]

Originally Posted by DavidCampen

Actually, I have decided that the NPK of a blended fertilizer is not very usefull and in fact misleading since it ignores calcium and magnesium which are at least as important as nitrogen, phosphorous and potassium.

I think that one can blend a good fertilizer using only calcium ammonium nitrate (YaraLiva Calcinit), magnesium nitrate (Magnisal) and potassium dihydrogen phosphate (MKP).

First determine the ratio of calcium ammonium nitrate to magnesium nitrate that will give you your desired ratio of calcium to magnesium. This also determines the percentage of nitrogen. For example, a 2:1 ratio of calcium ammonium nitrate to magnesium nitrate gives you 4:1 calcium to magnesium ratio and an NPK of 14-0-0 (12.7% Ca, 3.2% Mg). Then add MKP to get the desired amount of phosphorous and potassium. For example, 2:1:0.25
blend of Calcinit, Magnisal and MKP gives:
NPK 13-4-2.7 (11.7% Ca, 3% Mg).

You certainly have a much better understanding of the chemical makeup of fertilizer than I do. I agree that calcium and magnesium are important elements according to everything I've read. Unfortunately Magnesium and phosphorus compete with each other for uptake by the plant. I've been using a calcium/magnesium supplement by itself, twice a month on my orchids and they seem to be doing well.