Re: K uptake rate
Pretty variable.
1.Plant species dependency
2. Concentration dependence
3. Lots of luxury uptake
4. Highly mobile thus allows for the translocation
5. Genetic adaptation to various concentrations
Generally, using the NO3 as proxy for estimation based on demand seems to be a useful method.
Most aquatic plants tend to have about a 1:1 ratio of N: K.
But.....that does not imply that is optimal for growth, it's certainly way beyond limiting levels of K+ which is roughly a factor 4x less.
So an uptake of 1-4ppm a day might be generous, but the actual limiting levels are 4x less, so 0.25-1ppm is likely not limiting for most plants.
Regards,
Tom Barr