Science Buddies: "Ask an Expert"

Hi!

I am looking at the upcycling seed paper project:

https://www.sciencebuddies.org/science- ... seed-paper

I am worried whether the paper products we use (newspaper, cardboard, construction paper, etc.) have enough NPK content to provide enough boost to the plants to hold up to the positive control group? Paper is just made of cellulose fibers? I am a bit confused here. Any help would be appreciated!

Thanks,
Swapna

Hi!

I think the issue you're running into here is that, while you are altering the presence of fertilizer in each trial (positive and negative controls), the paper is not the source of the NPK. You are correct in that paper is mainly made up of cellulose, and thus would not have a great deal of Nitrogen, Phosphorous, or Potassium. In other words, while you are changing the type of paper, the amount of NPK in the 'soil' should not change unless you add fertilizer (change the positive/negative conditions).

Hope this helps!

To add to what Leir has explained, another thing to keep in mind is that the goal of the project is to test if paper can be a good slow-release fertilizer compared to a soluble fast-release fertilizer.

Fertilizers have more chemical composition than the three NPK micronutrients. For example, paper is a good source of carbon.

Another thing your student will want to consider is that fast-release fertilizers can be harmful to the environment through nitrogen compounds leaching into waterways.

Amy
Science Buddies