As I mentioned in my last compost post, I used my own black gold last fall to shore up my backyard for winter. I dug out the dirt, and stuff that was close to dirt, from the bottom of the compost bin and laid it around plants, finishing it off with a layer of dried leaves. This spring, I wanted to use my home-made compost to replenish the nutrients in my outdoor containers, which I didn't bother to empty this winter. I included some organic fertilizer too, since I know homemade compost doesn't have all the nutrients plants need. Only after I sowed my spinach and pea seeds did I think - wait, didn't I read something about maturing compost?
The Missouri Department of Natural Resources has a nice webpage explaining how to use compost, including the fact that compost should be matured (i.e. aged), as fresh compost can cause problems for your plants. One is that fresh compost can "burn" the plants. The second is that during the process of decomposition, nitrogen is leached out of the soil. It's only after the process is complete that nitrogen can be returned. Oops...
So I decided to make a fifth grade science project. I filled another two containers with store-bought compost and planted the same spinach and peas. Presumably, if the seeds sprout in both, then my compost was mature enough to plant in.
Then I'll make a poster with the results and bring it to the high school gym ;)