Many guys have different opinions about gardening, but a lot of it has too do with where you live and type of soil. I discoverd in real loose soil with a lot of compost, small amounts of top soil and clay you are in for a rough time. What I mean is that you plow or till down so deep that the soil can not hold the root systems of top heavy plants, like tomatoes, corn, squash and others.
Its good to plow, disc and find out what your garden space is at first starting out, like breaking new ground, clearing out large rocks that will damage equipment. Once my garden spot is established, I use the Buck with a 4' Befco roto-tiller to loosen the soil to a depth of about 3-4 inches and it also makes a bed 4' wide.
The bottom ground is hard enough to support the plants. I till my garden all year spring, summer during the growing cycles and fall as I prepare it for the next season, adding leaves and other compost.
I guess the fool proof way to determine the soil condition is to dig down and pick-up a hand full of dirt and ball it up in your hand. Drop or release it and watch what it does. If the ball hits the ground you are fine, if it is fine powdery soil and not compact, than you have what I mentioned above---TROUBLE---Too much organic compost--Yup its good, but you can over do it also.
Things like manures and things--it is best to place them in a barrel in the hot-hot sun or on a plastic tarp and cover it with a tarp. This kills grass seeds / fungus. A clear plastic tarp or cover will solarize the soil also and kill grass, bad fungus. Use a premium grade fertilizer with calcium.---I am not an expert, but some things I learned the hard way.
I think I have talked myself out of selling my Farmall Cub with all of the plows, to cultivate between the rows. Guys do I need both tractors--my wife said no---Need some advice at the end.----Thanks guys--sorry for the long post----Jim