‘Feed your worms and soil microbes’ has consistently been the best advice I’ve found to give people in terms of soil improvement and productivity, for both vegetables and fruit trees. A layer of compost followed by mulch (anything from straw to wood shavings to tarps, at times), to keep moisture in the top 6 inches of soil and keep it active, is the best way to solve many soil issues.
Past that, leaving roots of previous seasonal plants is also very helpful. Just cut them off near the surface and shred the tops into your compost system.
Monitoring and mildly amending soil pH can also be important, but usually less so.
A few years ago I got adopted a gecko and had been learning how to make a bioactive terrarium. Using insects such as mealworms/darkling beetles, isopods and springtails to clean up waste, decaying matter and mold.
From that I learned how valuable it was to have a complex eco system in order to make it function. This year I built a garden bed and took all the knowledge and observations from my terrariums and applied it to my garden. I didn’t focus on my crops as much as I focused on created a healthy soil bed for my crops.
I planted clover for ground cover. It provides shade and cover for all the little insects above ground. It retains moisture for anything below ground. It pulls nitrogen into the ground. It also looks pretty.
I placed stones for stepping on but also a place for the crawly things to hide. They love the underside of stones. I don’t have to trample and compact the soil whenever I step inside the garden.
When pruning back my tomato plants, I’d cut the cuttings into small bits and throw it back into the garden bed. It was broken down quite quickly.
I let a few wild plants grow a bit. Eventually I’d pull them, cut them up and toss it back in to be broken down like my tomato plant cuttings.
My garden eventually got to the point where I’d water it every 2-3 days because the soil was still very moist. Always easy to find isopods crawling about. If I dug a bit, I can find worms. The variety of plants brought around lots of different pollinators. My cherry tomato plant is outlasting my neighbours plant although the cooler weather is finally catching up to it and the leaves are just starting to wither. My kale is still growing strong and is almost as tall as me now. The swiss chard is still going as well to my surprise. The rest of my crops have rather died off or producing their last bits of seeds.
I’m considering gathering some fallen leaves this autumn to throw on top of the garden. Add a bit of variety to what gets broken down in the garden.
It’s been a really interesting experience so far and I hope to learn and observe more next year.