The man Rudolf Steiner was not an agriculturalist. He says so himself, though he did grow up in the country and helped with sorting and planting potatoes and breeding hogs. He does not seem to have been particularly inclined to deliver the Agriculture Course but due to the persistence of Count Keyserlingk's son, Steiner agreed.
The premise of the Agriculture Course delivered in Koberwitz, Silesia (in what is now Poland) was the degeneration of food supplies. The backdrop of 1924 had seen mass famines, starvation, and rampant disease from malnutrition. Steiner was begged to address these concerns from his esoteric spiritual perspective for the sake of humanity.
Steiner concedes that, yes, food quality has declined and that life must be restored to the earth, not merely chemicals. If there is one principle central to biodynamics, it is this: LIFE begets LIFE. The cosmos itself is dynamic, breathing, and alive, or life on earth would not arise.
As such, how do we restore healthy life to the soil? We do this with responsible common sense farming, incorporating the latest scientific research plus biodynamic preparations. We don't have to exclude anything that works. Whether we agree with the rest of what Steiner thought, we can all agree on the primacy of LIFE.