Depends on the expense Mark and what you would learn. Here a simple soils test is very inexpensive as compared to foliage analysis. I have the county test my soils for free and I bought a sampling test kit to do supplemental tests in key areas. I also purchased a soil testing meter that measures moisture, ph, and light levels.
I find these articles on CEC pretty informative about improving soil fertility. They would be applicable once you have soil test results.
Soil science and CEC articles
Benefits of soil organisms: Soil Organism - an overview | ScienceDirect Topics
Do earthworms create humus?
Earthworms can eat their weight in organic matter and soil each day to create nutrient rich castings. Earthworms help create humus—a dark brown-black type of soil which holds important nutrients in place for plant growth and use.
How Does Humus Help Plants Live?
Municipal leaf waste nutrient components
Benefits of nitrogen fixing legumes, crimson clover best winter cover crop to plant in spring. Alfalfa, white and red clovers are perennials.
Nutrient availability influence of CEC:
How does Organic matter influence CEC of Soil?
It influences the soil’s ability to hold onto essential nutrients and provides a buffer against soil acidification. Soils with a higher clay fraction tend to have a higher CEC. Organic matter has a very high CEC. Sandy soils rely heavily on the high CEC of organic matter for the retention of nutrients in the topsoil.
What is humus and why is it important?
Humus is dark, organic material that forms in soil when plant and animal matter decays. … Humus contains many useful nutrients for healthy soil. One of the most important is nitrogen. Nitrogen is a key nutrient for most plants.
What is humus and how is this beneficial to plant growth?
It’s called humus when it has completely decomposed. It is the thick brown or black matter that remains after the decomposition is complete. Humus contains many nutrient minerals that improves the health and fertility of the soil. Carbon is critical for healthy soil conditions, and humus is roughly 60 percent carbon.
Humus allows soil organisms to feed and reproduce, and is often described as the “life-force” of the soil. The process that converts soil organic matter into humus feeds the population of microorganisms and other creatures in the soil, and thus maintains high and healthy levels of soil life.