Input on a plant nutrition experiment

["Ellen T. Paparozzi, PhD" <hort010@unlvm.unl.edu>]

Hi all - We are about to start (in mid February) a large, labor intensive
plant nutrition experiment.  It will be 81 treatment combinations (4 x 3
factorial)with only 20 treatments replicated.  It's main purpose will be to
serve as a model data set for our new efforts identifying novel statistical
designs and methods to examine 3 or 4 nutrient interactions at a time. We
will use 3 levels of N (50, 125 and 200), S (0, 12.5, 25), Fe and Mn. We
will be using Red Freedom poinsettia - grown vegetatively in a 1 peat:1
perlite: 1 vermiculite mix with CaCO3 added to adjust pH.  I would
appreciate input on 
        1) the levels of Fe and Mn to explore - we are considering 0, 1.375
and 3 mg/L for Fe and Mn at 0, 0.77 and 1.5.  The goal is to use a deficient
level, minimally sufficient level and a higher sufficient but not too high
level.  
        2) look at the levels of the rest of the elements to see how they
compare to levels you have had experience with.  Nutrient solutions (set
volume) will be supplied with every watering such that 3 times plants will
receive the cocktail and once CaNO3 at 100 ppm Ca.
        P       60 mg/L                 K       228 mg/L
        Mg      40 mg/L  enough???   
        B       0.28 mg/L               Cu      0.14 mg/L
        Mo      0.14 mg/L               Zn      0.22 mg/L
        Cl      6 mg/L                  Na      1.5 mg/L

I really appreciate any other thoughts and comments as we would like this
experiment to work well the first time through.  Thanks, Ellen Paparozzi