Science Buddies: "Ask an Expert"

Posted: **Sat Mar 12, 2011 9:43 am**

Im nearly finished my experiment on 'Effects of nitrogen, phosphorus and potassium on grass growth' the thing is I didnt measure the grass each day should I have my hypothesis is 'If i apply different fertilisers to grass then they each would have a different effect on the grass growth' is this ok and what are variables?

im confused!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Posted: **Sat Mar 12, 2011 9:11 pm**

Hi!
Interesting project! So if that is your hypothesis, your independent variable would be different fertilizers and the dependent variables would be grass growth. However, in order for you to complete this project, you need to have a methodical way in which to measure how much grass growth there is. For instance, we give the suggestion that you should measure the grass height everyday in order to quantify grass growth. If you didn't measure the grass every day, you should have used another method of measuring your grass growth. Hope this helps!

Posted: **Sun Mar 13, 2011 5:22 pm**

Hi,

This is a great project, but you do need some measurements. If you haven't measured anything yet, it's not too late if your project is not due until April 9. There are a number of methods for measuring plant growth, and the guide on the Science Buddies website includes all of the possibilities:

https://www.sciencebuddies.org/science- ... owth.shtml

I recommend that you cut the grass and measure the length in millimeters of all of the samples every day for 7-10 days. This will give you quantitative data that you can plot on a graph.

Donna Hard

Science Buddies: "Ask an Expert"

Grass measurement+variables

Grass measurement+variables

Re: Grass measurement+variables

Re: Grass measurement+variables