I try to aerate my pastures twice a year, spring and fall. In the spring I wait until I can get into the fields but in the fall I need to wait until some rains come to soften up the soil. The tines go into the soil about 3 1/2" or so. After this I re seed with pasture seed and then harrow. I have some of the best pasture around this area or so my neighbors say. Now some of them are doing the same. My CA 2572 has not failed me yet but it will not penetrate hard ground, you have to use it when conditions are right.
Kevin