Recycling earth

Hi,
I've started growing trays of wheatgrass on my balcony. I heard that I could recycle the dirt but am a little lost as to the procedure. The roots take over most of the soil and leaving it in a big pot has attracted insects. Should I be mixing fresh dirt with the old dirt? Should I let the old roots dry out in the sun before mixing new dirt? Anyone have any sucess stories?
Liba

I compost my flats of barley grass,sunflower greens and buckwheat by using a basic compost pile.This keeps my costs down and supplies me with an exellant growing medium.It does take some space and some physical effort but the rewards are well worth it.I use a wire mesh to grate the flats which breaks up the clumps and preps the compost for use.I then add vermiculite along with azomite and some kelp.

Thanks for the answer...Do you put the flats with the newly cut grass through the wire mesh or do you wait till they're dry? Do the flats have to dry out before being covered with other dirt, kelp or verm...? Someone told me compost needs oxygen or it turns disgusting. I don't have much room on my balcony for huge buckets to allow space for oxygen..

I use a compost pile,the fresh flats are more difficult to recycle.I use a shovel along with a foldable 6ft table 2, 5 gallon buckets and a good pair of work gloves.There are compost devices that are drum like and have a stand for people with limited room for there composting.I have heard of people composting indoors along with vermicultures as well.Do a search on composting indoors and you should find plenty of ideas that can fit your needs.

Thanks again. I will look into that!