Nitrogen Depleted??

My daughter is just finishing her science fair project. She has four worm bins which she fed different types of food (fruit, veggie, egg/coffee, and grass/leaves) for the last three months. There have been no problems and the worms have been eating well and seem quite content. The hypothesis of her project was that the bins would produce different levels of nutrients that would then could be best used for optimal production of different plants or at different times of plant development. Well the day arrived to test all the soils on Sunday. She had to wait an extra day just to let the soil settle in some of the water, but she completed all the tests last night. Our surprise (and she re-did each test) all of the bins came up Nitrogen deficient??? They had varying degrees of Potash and Phosphorus and varying levels of PH, but no color came up on the Rapitest for Nitrogen. She has one week before she has to turn everything in, any thoughts out there???

Interesting... Did she do a control to check the test strips? Something like a solution of high nitrogen synthetic fertilizer. Titrate it down to get a reading in the range of what she was expecting for the worm castings. It might also be interesting to see if your local ag lab could run their more exact tests on a sample. (Maybe they would do a rush job for a science fair. Really cool maybe they would let her watch.)

http://forums.gardenweb.com/forums/load/verm/msg101357579147.html has some discussion. Note especially the part about a baseline, the amount of nitrogen in the inputs. I don't know how much library work she did ahead of time, but it sounds like this may end up being a project with a significant literature search component.

Try to help your daughter not feel discouraged or frustrated because it didn't come out like she expected. She's doing real science! There are lots of little science fair projects that aren't real experiments because they've been done to death and everyone knows they "work". Her "failure" is actually a GOOD experiment - she learns something about worms, and also about experiment design. And there's no reason she can't present that as a strong entry in the fair.


Let us know...

Thanks, Realbirdlady! We took your advise and retested using some nitrogen fertilizer that we had in the garage and still nothing showed up on the test. Then, my daughter wrote the doctor in charge of the lab that does soil samples for our area and he referred to another specialist in the lab that has done a lot of work in the area of composting. Bottom line, we don't know why the Nitrogen is not showing up on the test (faulty test, nitrogen fixation, the test may have only react to inorganic nitrogen, or nitrogen leaching), but they are doing a rush soil analysis for her testing for both organic and inorganic forms of nitrogen. Thanks for your advise. She's excited and learning a lot! I'll write again when we know more!

Interesting research Wmarsich. I'm excited for your daughter. Tell her we'll be rooting for her to win the contest and interested in her results.