Does anyone have any experience with the biodynamic preparations applied on large scale?
The Josephine Porter Institute sells a Field spray that contains all the preparations. The problem is it's $24 and good for one acre. I'm looking to do something with several hundred acres. Does anyone have any info for this scale of biodynamics?
Obviously, the cheapest way would be to make your own BD500. I do not make my own, but I do not have a ranch. If you already have cattle and manure, it would be better to do it yourself.
The Pfeiffer Field Spray is basically microbe food - it just feeds the bottom of the food chain. Bacteria have the highest protein by weight of any organism in the soil: provide them food, and they show up... then earthworms, and your soil begins healing itself.
I expect if you simply composted your weeds, manure, etc. and used the finished compost as a diluted "compost tea" this would suffice. An orthodox biodynamic farmer might disagree with me, but you have to make do with what you have. And a shared principle in biodynamics and permaculture is: creating fertility from what you already have.
I know a number of these farmer-thinkers would use extremely dilute homeopathic forms of these preps with apparently good results. Think again in terms of microbe food: you don't need much to jumpstart the process.
The BD500 spray, from what I can tell can benefit from spraying both when the Moon is "descending" (during what Maria Thun calls the "transplant time") AND in the very late afternoon. The logic is: you want it to soak into the soil, not evaporate; the moon, when "descending" is supposedly pulling water down into the soil.
I hope that helps. This is what I've extracted from much reading.