Karen (UR) Old MacDonald had a farm >>

And on that farm he had fertilizers and a lot of manure.  Too bad no one taught him a safe and environmentally friendly way to turn that waste back into a way to feed, fertilize and irrigate his farm.

Thanks to Dr. Woodall for the input on my IRP, I now have my question and have revamped my experiment.

First, the question:  Is there a level of N (nitrate) that will kill the duckweed?

Now for the change in my experiment:  I will be using 4 culture dishes, 4/12 inch in diameter with a 250ml capacity.  There will be one control; DI water (150ml) and 3 that will have the same amount of duckweed and 150ml of water.  The control will have no plants and I will count out the duckweed plants for the other 3 so that each dish has the same amount, haven't decided on what that amount will be.  When I receive the plants, then I'll make that decision.  These plants are very small.

I will monitor the water level, nitrate amount and evaporation rates every 48 hours as well.  Adjusting water levels for evaporation and transpiration as needed.

Because of the limited amount of time for my IRP, I am as yet unsure of how much nitrate I will add to the water.  

Lemna minor  The little plant with big possibilities