Science Fair Project – Effects of Nitrogen

Q: I am doing a Science Fair Project on, ‘How does the amount of nitrogen in a fertilizer affect the height of a bean plants stem under normal growing conditions’.

I was wondering if you could give me some information on how to get fertilizers with the same amount of phosphorus and potassium, but different amounts of nitrogen.

And lastly, is a bean the best plant that I should use because I am examining over a two week time period. Do you have any tips?

One way to mix your own fertilizer to have differing amounts of nitrogen would be to get three basic fertilizer ingredients from the garden store: ammonium nitrate (33-0-0), triple super phosphate (0-46-0) and muriate of potash (0-0-60).

Mix 2 tablespoons of 0-46-0 with 1.5 tablespoons of 0-0-60. Dissolve the resulting mixture in one gallon of water. You’ll have a solution containing approximately 2000 parts per million of phosphorus and potassium.

Next, mix 2.5 tablespoons of 33-0-0 in a gallon of water. This will be your nitrogen source, also approximately 2000 ppm.

All three are pretty concentrated. Plants like their fertilizer to be around 100 ppm. That means you have to mix one part (of either of the two solutions) with ten parts of water to make a 100 ppm solution that you can give your plants.

You could change the amount of water you mix in to make a different concentration of nitrogen.

A: One way to mix your own fertilizer to have differing amounts of nitrogen would be to get three basic fertilizer ingredients from the garden store: urea (46-0-0), triple super phosphate (0-46-0) and muriate of potash (0-0-60).

Mix 2 tablespoons of 0-46-0 with 1.5 tablespoons of 0-0-60. Dissolve the resulting mixture in one gallon of water. You’ll have a solution containing approximately 2000 parts per million of phosphorus and potassium.

Next, mix 2 tablespoons of 46-0-0 in a gallon of water. This will be your nitrogen source, also approximately 2000 ppm.

All three are pretty concentrated. Plants like their fertilizer concentrations to be around 100 ppm. That means you have to mix one part (of either of the two solutions) with twenty parts of water to make a 100 ppm solution that you can give your plants.

You could also change the amount of water you mix in to make different concentrations of nitrogen.