Is uptake rate dependant on nutrient availability?

The answer at first glance would seem to be "yes", but I suspect that it goes a lot deeper than that.

I'm gonna set a theoretical standard for a tank. 4.4WPG,75 gal tank, c02@30ppm, abundant micro nutrients. Abundant plant mass.

Scenario 1: 20ppm nitrate, 2ppm phosphate, 20ppm pottasium

Scenario2: 5ppm nitrate, 0.5 ppm phosphate, 10ppm pottasium.

Do the plants in scenario 2 have a more difficult time of extracting macro nutrients from the water column due to the relative scarcity of macro nutrients in the water column as compared to scenario 1? Does the rate of nutrient uptake slow down because of this relative scarcity?

Notice that I kept the ratio of N-P at the "mythical 10-1 ratio". My plants always seem to do better with more P. Would a higher percentage of P relative to N push nutrient uptake further? When is more macros too much, and when is less not enough? It seems logical that there must be a point of diminishing returns at both ends of the scale.


Marcel