nutrient needs of given plants

[caverdude]

Is there an authoritative book or source to show which plants need which nutrients and in what quantities?

[rainbowgardener]

I think you are over-thinking all this! (I'm guessing you are a kind of geeky type who tends to over-think things -- it's OK, many of us are! Why else are we sitting at our computers typing about gardening esoterica? )

If you just work on having rich soil with lots of organic matter that contains a full spectrum of nutrients, then the plants will just take what they need and you don't need to provide anything special or know what it is (outside of a few basics like pH). Plants do grow in nature, without anyone providing any special nutrients other than what the soil provides in a balanced eco-system.

That's why we recommend compost so much and push the idea that your compost pile should be made of a diversity of ingredients, carbon rich and nitrogen rich and varied, no more than 10% of your pile any one ingredient. That way you are adding that full spectrum of nutrients to your soil and you can relax and just let your plants take what they need.

[caverdude]

yes I like to calculate things and like statistics and such

[rainbowgardener]

I just noticed that this is in the hydroponics forum. If you were talking about hydro, that would be very different, since in hydroponics you do have to supply all the nutrients. But everything else you have been writing about is soil and compost.

But if you are talking about soil, there is just no point to worrying about the different nutrient needs of different plants. In a complete soil, the plants will take what they need. Not to mention that like much of what you have been asking about, it is pretty impossible to quantify - the same plant needs different kinds and amounts of nutrients depending on the season, on whether it is currently small and just growing roots, larger and growing lots of leaves, flowering, fruiting. At all those different stages of the plant life cycle, it has different nutrient needs. And then if it is more stressed, if the weather is hot or cold, if it is suffering insect attack, etc etc. All of those things could change the best nutrient profile for that plant at that time.

You are not smarter than Mother Nature! Just supply good rich soil.

[caverdude]

All very good thoughts and info, I am simply asking questions to understand on a deeper level, why and why not. Thanks