# What elements plants are made of, and at what concentrations



## Salt (Apr 5, 2005)

This is from _Mineral Nutrition of Plants: Principles and Perspectives_ by Emanuel Epstein and Arnold Bloom, which was originally published in 1971.

These are the main constiuent elements of dried plant tissue:


```
Carbon      - 45.2100%
Oxygen      - 45.2100%
Hydrogen    -  6.0300%
Nitrogen    -  1.5100%
Potassium   -   .7245%
Calcium     -   .4346%
Magnesium   -   .2607%
Phosphorous -   .2607%
Sulfur      -   .2028%
Iron       -   .0529%
Chlorine    -   .0529%
Manganese   -   .0265%
Boron       -   .0106%
Zinc        -   .0106%
Copper      -   .0031%
Molybdenum  -   .0001%
```
A lot of people are probably already familiar with this but I thought it might be interesting to anyone who hasn't seen it. I believe most modern macro and micro fertilizers are based around this.


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## mrbelvedere138 (Jan 18, 2006)

Now are aquatic plants of the same composition as terrestrial ones? Calling Tom Barr......


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## plantbrain (Jan 23, 2004)

edit


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## BryceM (Nov 6, 2005)

Some people mistakenly think that just because a plant is made up of 10 times more X than Y, that they need to dump in 10 times more X than Y. These composition numbers are interesting, but don't base your entire fertilizing program around them. It usually isn't so simple. Like all living things, plants are better at extracting some nutrients than others. Many elements need to be present in larger concentrations than you would expect while plants are perfectly capable of assimilating even minute quantities of others.


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