Farmers using biodynamic principles understand that only life begets life. As such, when we use synthetic fertilizers, these can at most be drivers of growth that is already there. But for plants to thrive, life must be restored to the soil itself.
In his original Agriculture Course lectures, Rudolf Steiner repeatedly urged farmers to keep farming as you have been farming and to keep adding manure to your fields. He even declines to speak about composting methods when questioned because biodynamics is first and foremost about what works and Steiner's indications were to add the biodynamic preparations to normal sustainable farming methods. As such, biodynamics is a kind of medicine to add to a sick farm, but it does not change everything about farming.
Biodynamics does not seek to "reinvent the wheel" nor should it. Instead, biodynamics seeks to supply the necessary kinds of vitality necessary for each stage of plant growth. The term "holistic" can be used rather loosely, but in biodynamics we mean it. We take something from the whole farm -- all sorts of herbs -- and even from whole animals. The idea is to draw from the plant an animal worlds so that the right enzymes, nutrients, and vital energy is available for every stage of plant growth to be healthy. That's all we're looking to restore: everything necessary for healthy plant growth. This integrates with any responsible form of farming.