Turner, Frank Newman. Fertility, Pastures and Cover Crops Based on Nature’s Own Balanced Organic Pasture Feeds. reprinted from:  Faber and Faber, 1955. ed., San Diego:  Rateaver, 1975.

An encouragement to farm using long rotations and green manuring systems from a follower of Albert Howard.  Turner offered a remarkably sensible definition for soil fertility, in essence, “if my livestock stay healthy, live long, breed well, and continue doing so for at least four generations, then my soil was fertile.”

Voisin, Andre. Better Grassland Sward. London:  Crosby Lockwood and Sons, Ltd., 1960.

The first half is an amazing survey of the role of the earthworm in soil fertility.  The rest is just Voisin continuing on at his amazing best.  No one interested in soil and health should remain unfamiliar with Voisin’s intelligence.  See also:  Grass Tetany, Grass Productivity, and Soil, Grass and Cancer.