In article <1995Feb13.211736.13105 at es.dupont.com>,
heldreth at esvx12.es.dupont.com wrote:
> I would like to demonstrate Nitrogen deficeny, Potassium
> deficency, and Potash deficency in soybeans for a class room project.
>> I thought the easiest way to demonstrate these plant stresses
> would be to:
> 1) propagate the soybeans in a metromix type media, (low
>> 2) feed the control plants NO3, K, and H2PO4, and
>> 3) feed the demo pots the same amount of the nutrients supplied
> to the control, minus the nutrient I wanted deficent.
>> I wondered if there is a better method? My concern is that
> the soil media may still supply enough nutrients to overcome the
> deficency I'm trying to create. What would effectively tie up each
> macronutrient and make it unavailable to the plant?
>> All methods and comments are welcome! Thanks!
Try using acid washed sand. You won't have any problems of contamination
of your experiment with nutrients from the soil.