https://www.quora.com/Why-isnt-it-common-to-grow-corn-hydrop...
In western Canada farming practices involve more crop rotations and less tillage, the net result has been increasing organic matter in many areas. I farm in an area with a surplus of organic matter, and too much can be a problem, so we still engage in a lot of tillage under normal precipitation conditions.
https://agriculture.canada.ca/en/agriculture-and-environment...
I am a bit of gardener and my anecdotal advice is - I don't know what sense you are using the word "mulch" here so I am not sure about that but too much compost can be an issue if you are not letting it break down long enough and not incorporating into existing soils well enough. Too much compost will grow wicked-hot radishes, but your leafy greens will be ugly and taste like garbage in my experience. The thing about gardening is it is all small sample sizes.. it ain't science and it is hard to know what's up without a good old fashioned site visit!