10 years ago I planted some baby macadamia nut trees. I did nothing the change or improve the soil, I simply planted the trees. Since that time I have done no tilling around the trees at all. But I have kept a constant mulch covering. Sometimes it is grass clippings. At other times it's compost. I'd venture to guess that fresh mulch was added 4 to 6 times a year, as needed to keep the ground covered. About twice a year I watered the trees well with manure tea made from composted manures. I sometimes also used diluted urine solution, but I honestly don't recall how often it was applied.
So today I raked off the mulch and tilled the top couple inches. I was surprised to see that the soil didn't look much different than when I started 10 years ago. Even with all that applied mulch, the soil was still light red and very cindery. It was granular and did not have visual organic content. Only the top 1/2" right under the mulch was dark and looking like garden soil.
Above, the lighter colored soil that I'm pointing to is a small handful taken from under the macnut tree. I poured it atop the garden soil, only 2 feet away, then took the photo. The garden soil is obviously darker in color, it is crumbly and full of organic material. It feels and smells like good garden soil. It feels nicely moist. The light reddish soil is gritty, dry, appears to contain no organic material. The color contrast is significant.
I was under the impression that by not tilling or digging, but rather by using top dressing alone, one would improve their soil via the no-till method. I've seen that claim published in numerous discussions of no-till. Hhmmmmm. That doesn't appear to be the case for my type of soil. Top dressing and the use of manure teas did not enhance the appearance of the soil around the macadamia trees.
This little observation just reinforces my belief that light tilling combined with mulch and compost applications creates better soil for me than using no-till methods being touted by the latest fad in gardening. No-till very well may work in other situations, but it surely isn't doing the trick for this farm....at least not in this stage of development. I'm sticking with my compost piles and tiller.