[Plant-education] basic greenhouse experiment protocol question

[Ginger R.H. Allington]

Hello! I am a field ecologist embarking on a little side project in the
greenhouse, and I have a few basic questions re: protocols and I can't seem
to find straight answers online.  I am hoping to gather some input from your
collective experiences.

I am engaging in a very simple little greenhouse experiment testing the
impact of nitrogen addition (Control, Low, Med, High) and watering regime on
germination and survivorship of a series of grasses native to my research
site.

My Qs:
-In such experiments, is it typical to use a fertilizer that includes other
micro (and/or macro) nutrients (e.g. Hoaglnand's), or can/should I use a
straight Nitrogen fert?  If so, what would you recommend?
If a mix is best: I do not have the resources to mix up Hoagland's solution.
 Do you have a recommendation of an alternative fertilizer to use for
N-addition treatments?

-In such experiments, is it best to use a sterile growth medium such as a
sand-vermiculite blend, so as to avoid the addition of nutrients from the
breakdown of organic material in potting mixes (e.g. peat)?

I know these seem like very basic questions, but I appreciate your thoughts!

-- 

gallingt from slu.edu