The primary reason I've gone back to heavy tillage practices is because of our local conditions. The ridge-tops where most of our plots are located are pure chert gravel held together like concrete by a little clay in between. Go down 6 to 8 inches and you hit 4-6 inch layers of solid chert rock (which tends to break into grapefruit-sized chunks). The two biggest problems with trying to food plot in this soil is lack of actual soil profile and the surface hardpan's inability to allow rainwater to percolate down into the soil and carry any nutrients with it. Even after a torrential summer thunderstorm, an inch down the ground is bone dry. Water runs right off. To get water and nutrient transport downwards, and to produce an actual soil profile, we HAD TO break the surface hardpan.
In late summer, I've tried everything to break the surface hardpan, and nothing works. Not discs, no chisel plows, not tillers. Perhaps a dozer with rippers would work but that would bring up a huge amount of rock. The only way I've found to break the surface hardpan is to try it the first time in early spring when the soil has its maximum water absorption from winter rains, say sometime in early to mid March. At that point a very heavy disc like a forestry disc would be able to turn the ground enough for a rotary tiller to work with it.
For years I tried the no-till method of soil-building, where biological matter is mowed down onto the ground and allowed to build a humus layer. However, after years of doing this I found I was building up about an 1-2 inches of humus, but that was sitting right on the hardpan. Digging up growing plants showed me their roots were running sideways right along the top of the hardpan. That won't get plants through a droughty summer.
Now that I've tilled the plots for 3-4 years, I've got 4-6 inches of nice humus. It's STILL sitting on a hardpan, but at least the hardpan is 6-8 inches down. Plus I've found 4-6 inches of tilling allows rainwater to really soak in. I THINK the soil will finally hold enough moisture over the summer to grow summer annuals. But we shall see...