We haven't done the chemical fertilizer thing in quite some time. Generally, we use a multifaceted approach to soil fertility. We amend lots of compost into the soil, leaves, biochar, organic matter. Then we use fish emulsion for foliar feeding as well as around the base of the plant. Prior to planting, we incorporate composted wood chips with composted cow poop and chicken poop into the soil.
I've been looking at other ideas and wanted to do an experiment on a small scale prior to going full-throttle with it. It has to do with making liquid fertilizer concentrate with things you have not far from the garden. Weeds! In my hand below is an assortment of winter grasses. I got a sling blade and chopped a 5 gallon bucket full of weeds. Weeds have everything you need to get started.
The next thing you need is leaf mold. Leaf mold can be found in the moist forest floor. I didn't even need to go to the woods. I dug into the wood chip pile that is decomposing and found plenty of it. Leaf mold contains mycelium. Mycelium are the white thread-like fungi that are working behind the scenes to turn wood and leaves into topsoil. In addition to your 5 gallon bucket of weeds, add a handful of leaf mold.
Put both the weeds and leaf mold into a bucket.
Fill the bucket with rain water.
Snap the lid on the bucket securely and set the bucket in your garden in full sun.
Leave for several weeks and let it "cook." Then use the liquid to fertilize your plants. I'm told that you must dilute it, starting off weak so as not to burn your plants. We'll update you in a few weeks when we pop the top off. I'm told this stuff stinks to high heaven, so we were warned not to get it on your clothes. Maybe this will be done by the time we need to fertilize the cucumbers you see behind the bucket.