Several years ago we worked with a greenhouse grower where crops were being grown in the soil continuously for over a decade. The soil was quite sandy and became quite tired as you can imagine. The large investment in the greenhouse made it worthwhile to invest in regenerating soil health.
The grower green chopped cover crops grown in the field, applied them to the soil surface to a depth of several inches, sprayed Rejuvenate and Spectrum on the residue, and incorporated it into the soil. In 3 weeks the soil had noticeably darkened in color and had developed good aggregation.
The following crops grew better than they ever had in recent memory, and without any disease or insect pressure. Biology can regenerate soil health quickly and provide all the nutrition a crop requires when given a food source.
The soil sample on the right is from an untreated greenhouse bay, taken at the same time.