# Agricultural efficiency equation

First, I suck at math, totally, sorry if this is a real simple problem, but I am not sure how to handle this concept.I don't even know what branch of mathematics this would fall under, so please forgive me if I used the wrong tag.

What I need to do is take the following variables and end up with some sort of indicator of efficiency.

G = genetics/plant type (?)

A = total area (metres squared)

y = yield (grams)

P = total power consumed (watts)

n = nutrient costs (\$)

w = water consumption (litres)

t = time (days to harvest)

For the first variable "G" I am thinking that it would have to be based on overall light requirements, typically measured in PPFD or the plants desired daily light integral, this can typically be broken down into low light plants, medium and high light plants, ranging from 30 to 1500 micromoles per square meter per second (µmoles/m-2/s-1) or easier maybe the DLI which is the same expression over a 24 hour period (mol/m−2/d−1) eg tomatoes or bell peppers are high light plants requiring a DLI of 30+ mols/m2/d, DLI is probably best for simplicity's sake. I think, but am open to alternatives.

The rest of the variables are straight forward. So the idea is that we need some sort of equation that lets us plug numbers in and get an overall resulting efficiency. Typically we use a simple expression of yield over time or yield over power consumed, but that leaves too much out of the equation to be useful in comparing different growing methods, mediums etc. We need to take all these variable into account. In theory we could even need to account for CO2 inputs and airflow, but that's a little fringe at the moment.

Any help would be greatly appreciated! If I have an equation I can build a calculator for online use to help people narrow in on the best ways to produce specific crops indoors.