As those who cook may know, the quality of the heat matters. If you're grilling over an open fire, it has one effect. If you bake in an oven, quite another effect. If you microwave, yet another. What changes here is the quality of the heat the cook is using. This is one of the most important things in biodynamics: the quality of our inputs.
If we wish to have healthy plants, we should consider using healthy inputs. But that means reaching beyond soluble fertilizers which, let's face it, are not alive enough to be "healthy." Now, a particular chemical may be healthy or unhealthy for a living organism, but if we wish to foster healthy plants, we need to add heathliness back to the soil.
That means that we need compost that has no odor. It means we need to bring healthiness from specific medicinal herbs to our compost pile because those herbs are known to bolster health. It's almost as if the compost pile itself is a living thing full of invisible inner activities that can be healthy or unhealthy. The biodynamic compost preparations do just that: they encourage healthiness in compost, and help make your crops into healthier plants.