ive got to stop here and say that actually a plant will utilize nutrients the same reguardless of the source. for example nitrogen is nitrogen no matter where is comes from.
I get the lab environment. But I'm not arguing environment, I'm talking soil and bottles.
Here. Again, I'll use actual information. Above you say that nitrogen is Nitrogen.... Now you know that isn't true.... and please let's keep it coming!
Here is an article about the different types of Nitrogen. I love the title... Nitrogen: All Forms Are Not Equal
http://www.greenhouse.cornell.edu/crops/factsheets/nitrogen_form.pdf'
Now, you can guess to exactly what your plant wants and when, or you can let the rhizosphere handle it for you.... But here is where the problem is.
Notice in the article they talk about the PH effect of Nitrogen absorption? So when the soil handles itself, it also handles the PH just perfectly by balancing the whole process and how it actually utilizes the different types of Nitrogen available to it.
Why would I want to confuse the system and add more Nitrogen in any combination of the three types? I'd be guessing at best and so would the different profiles of the different nutrient companies. Your plant will do fine with just one type of nitrogen. That's just not my style. I like the plants to do their thing.... and this process works from all across the board on all my plants. Because I do grow a ton of food and again, I'm not convinced that nitrogen is nitrogen.
For another argument above the scale of the indoor gardens we have, take a look further down the above article and see how we are polluting the environment with nitrogen fertilizers. And there isn't a reason to in my opinion.