Quote:
Originally Posted by Ray
I don't think anyone knows for sure.
If you rely on tissue analysis, the rough breakdown is:
90% is water
9% is C, O, H (from air and water) and N
0.9% is Ca, Mg, P, K & S
0.09% is everything else
Carbon being about 50% of the total "dry" weight.
I am a bit skeptical of tissue analysis however, as what's in the plant doesn't necessarily mean it's what's required. Using myself as an analogy, if tissue analysis is truly indicative of "what the body needs", then I must need a lot of cholesterol!
Phosphorus and potassium are good examples among plants, as both are accumulated pretty significantly, whether needed or not. If I remember correctly, the degree of K accumulation is controlled by the concentration in the rhizosphere, while P is actively "snatched up" by the plant, gathering all it can, no matter what the concentration.
If you want to read an interesting article on the subject, Rick Lockwood had an article, What Do Orchids Eat, published in the AOS Orchids Magazine 3/2013. |
Hi Ray,
The article you linked was interesting. If I understood correctly long term use of potassium could have a negative effect on orchids?
So essentially Rick reduced the orchids potassium intake and increased Calcium and Magnesium. For someone who is using a balanced fertilizer, (in my case 20-10-20) if I were to reduce my normal dosage am I not also reducing the amount of nitrogen and phosphorus? Does the increase of calcium and Magnesium make up for the overall reduction of N-P-K?
Here is a quote from the article : "My reduced
potassium and increased calcium and mag-
nesium program was initially accomplished
by reducing the amount of MSU fertilizer
by half, and adding equal parts of calcium
nitrate and magnesium sulfate.This kept the
nitrogen and phosphorous levels constant
while drastically reducing potassium and
increasing both the calcium and magnesium."
But I dont understand how the nitrogen and phosphorus levels were kept constant? Unless I am misunderstanding what Rick was actually saying which is completely possible
Would appreciate thoughts and clarification!!
Hybrid Mode
