What depth are you guys cultivating/ploughing to, for standard cereal/oilseed crops? I am assuming that the depth has decreased over the last 10 years from the standard 8-10 inches of ploughing to 3-4 inches of min tilled approach.
Have the yields maintained? Is the soil in a better condition? Is it compacted? Does the crop establish evenly?
Not interested in the weed thing just the practice of establishment.
Cultivating (Carrier)to only 2-3" max, and subsoiling to no more than eight (Shakerator with winged share). Having min-tilled 90% of everything for the last five years we are finding the soil works much better and it is much easier to incorporate crop residues. Land that has been min-tilled for 7 or 8 years and has had most of the straw incorporated has a peat like surface. I think we may well be able to do away with any cultivations just harrowing to even out the trash then direct drill. Yields are higher but they probably would be anyway due to stobs etc, but in a dry year we do not suffer as muh as we did when ploughing. The soil structure is much firmer, but not compacted. (with the exception of some of our sandy/silts which set like concrete and require regular loosening). Crop establishment is far more even, so long as you get the residue evenly spread.
I guess it really is down to your soil type. We have heavy limestone land which if not ploughed becomes extremely compacted. Ploughing 8-10 inches every year, straw not incorporater but beet tops ploughed down.
On v alkaline clay / clay loam :- pre straw burning ban we disced to 2 inches and subsoiled every 2 or 3 years to 12+ inches. (plough and roterra were only EVER esed to produce firebreaks.)
post straw burning we plough to the min depth to bury the straw etc etc.(except after OSR – light min-till to spread trash)
Cant say there has been much yield influence one way or the other, as JB points out agronomy improvements make this a difficult call.
I do remember that in the straw-burning days yields were more stable in the min-tilled part of the field, but that could be as much to do with the ploughed headlands being farmed more as an afterthought (lack of packer-roller in particular) and consequently being ‘too dry’ come drilling date.