I have a fairly large garden about 30x65 or so. The soil is nice and black but there are no earthworms in it. I presume that there is little organic content. I till most of the plants back into the soil every fall plus any weeds that grow get tilled in. I surround my plants with grass clippings for weed prevention and moisture retention and that gets tilled in every year but still no worms. Yesterday I added a pick up load full of 3 yr old cow manure covering the entire garden and will till in today. Any ideas? I thought worms meant good soil. Had soil tested last year at extension and it was slighlty low on pottasium or phosphurus if I remember correctly but everything else was ok. Just curious is all. My garden does all right(providing mother nature doesn't kill it with hail, rain or wind) but never great. I hand water every single plant and there are zero weeds around them. Full sun as well.