concentrations of nutrients in soil

[flamingreddragon12594]

I am doing a project to show which nutrient stimulates the best growth or best results. The three nutrients I am testing are phosphorus, nitrogen, and potassium but I do not know how much I should increase the concentrations of these three nutrients in the three plants that I am testing on. Also, the sources of each contain ions so how can I get rid of the ions and cause them not to interfere in my experiment. What should I do? If you have any suggestions please let me know and thank you for your help.

[ChrisG]

Hi,
Interesting project. What sort of soil are you going to use?

As a starting point for nutrient amounts, you can look up the recommended fertilization rates for whatever plants you are growing. You can use higher application rates if you want, but you might harm the plants.

I'm not sure what you mean when you ask how to get rid of ions. An ion is a positively or negatively charged modecule or atom, and nutrients in solution are ions. For example potash is often applied as KCl (potassium chloride). This molecule dissolves and becomes K+ and Cl- ions. So, you can't get rid of ions, but you can, perhaps, create some experimental controls to make sure that ions like Cl- are not strongly affecting your results.

[kathleenkimball4]

That's a really interesting project! The soil is very important, like she said, though. Make sure you use the same kind and amount of soil in each test so that the results aren't skewed.
Why don't you start off looking at the normal amounts of each nutrient in the soil you're using and then increase that number by a certain interval for each test?
For example, say that there is .30 or something of nitrogen in your soil. Maybe you'll add .10 more to your first test and then .20 the next? You should look up the natural/healthy concentrations first to make sure that your figures are reasonable (the ones I used are completely hypothetical...I just used those numbers because it's easy to notice the difference)

[Louise]

I am doing a project to show which nutrient stimulates the best growth or best results. The three nutrients I am testing are phosphorus, nitrogen, and potassium but I do not know how much I should increase the concentrations of these three nutrients in the three plants that I am testing on. Also, the sources of each contain ions so how can I get rid of the ions and cause them not to interfere in my experiment. What should I do? If you have any suggestions please let me know and thank you for your help.

I'm also not sure about the 'ion' question. There are many ions and nutrients in tap water, so to minimize these it is best to buy distilled water to use.

Louise