waterng with grey water

[jarrod0702]

hey,
i am conducting an experiment where i have three pots wich all contain 3 plants. i am watering one pot with tap water (control), one pot with grey water from the bath tub and one pot with grey water from the washing machine. it has currently been going for one week and i finding it really difficult to find research to go with it. Could you help me find information for the following parts:

- What are the benefits to plants when supplying extra phosphorus and nitrogen.? (like if they get not enough or to much. They can be toxic i heard so what are some symptoms.?)

- What chemicals are in tap water and do they have any effects on plant growth. ?

- Any other information on greywater.

I would really appreciate if someone could help me for i am struggling to find anything.

[MelissaB]

Hi,

First, try looking up 'eutrophication' or 'nutrient enrichment' in your favorite search engine.

Here's a website with some information about plant nutrients: http://www.ncagr.gov/cyber/kidswrld/plant/nutrient.htm

Here's a slightly more technical one about phosphorus: http://www.ppi-ppic.org/ppiweb/bcrops.n ... 9-1p06.pdf

Here's one with effects of too little/too much of both N and P: http://soil.gsfc.nasa.gov/soilfert/npk.htm

Here is wikipedia's article on greywater; you can look at it and you can also take a look at some of the references it cites: http://en.wikipedia.org/wiki/Greywater

As for your questions about tap water, take a look at the National Academy of Science's water page at: http://water.nationalacademies.org/ and a discussion about tap vs. bottled water: http://www.pacinst.org/topics/water_and ... /index.htm .

Take a look at those resources and then let us know if you still have questions. One suggestion: Be sure to take a lot of pictures in addition to the variables you measure; it will eventually make for an exciting board! Also, you might want to consider having more than three plants in each category, particularly if you've just planted three seeds; it's typically preferable to have a sample size of 5-10 in each category because then you can start to argue that your results are not just due to chance.

Hope this helps!

[deleted-71447]

Hi jarrod0702,
To add to what Melissa said, the contents of your tap water depend largely on the source. If you are in a city with a public water supply, you can check with the public utility company that supplies your water. If you don't know this information, you can type the name of your city into a search engine followed by the word "utilities" and that will hopefully lead you to the info. Or just ask someone who pays a water bill in your area. If you live in a rural area with a private water supply, then there might not be any data on the chemistry of the water. But from the type of source (for example, limestone aquifer versus basalt aquifer) you can often make generalizations about the water chemistry.

Please keep in mind, plants are sensitive to the method of watering as well as the chemistry of the water. Evaporation of applied water causes increasing concentrations of solutes in contact with the plant roots. So you should try to be systematic about how you water the plants.

Good luck!
Chris