I don't apply chemical fertilizers, pesticides or herbicides in my gardens. This doesn't certify our gardening as organic, but is is pretty close.

Steve Solomon recommends (and I follow this) his complete organic fertilizer (COF) a specific mix of seed meal, lime (agricultural and dolomite), bone meal or rock phosphate, and kelp meal. I vary the proportions depending on the plant variety and nature of the soil.

See the article about Organic fertilizer recipes for details.

In The Intelligent Gardener: Growing Nutrient-Dense Food, Steve Solomon's 2013 book about scientifically amending soil for nutrient- dense vegetables, I find a comprehensive and rigorous framework for providing exactly the soil and plant nutrients that each particular bed or garden area needs. See the page on soil remineralization.