This nitrogen surrounds us on all hands. As you know, we have around us only a small proportion of oxygen, which is the bearer of life, and a far larger proportion of nitrogen — the bearer of the astral spirit. By day we have great need of the oxygen, and by night too we need this oxygen in our environment. But we pay far less attention, whether by day or by night, to the nitrogen. We imagine that we are less in need of it — I mean now the nitrogen in the air we breathe. But it is precisely the nitrogen which has a spiritual relation to us. You might undertake the following experiment. (Steiner 2007:25)
At this point I think you will have a true idea, of the necessity of nitrogen for the life of plants. The plant as it stands before us in the soul has only a physical and an ether-body; unlike the animal, it has not an astral body within it. Nevertheless, outside it the astral must be there on all hands. The plant would never blossom if the astral did not touch it from outside. Though it does not absorb it (as man and the animals do) nevertheless, the plant must be touched by the astral from outside. The astral is everywhere, and nitrogen itself — the bearer of the astral — is everywhere, moving about as a corpse in the air. But the moment it comes into the Earth, it is alive again. Just as the oxygen does, so too the nitrogen becomes alive; nay more it becomes sentient and sensitive inside the Earth. Strange as it may sound to the materialist madcaps of to-day, nitrogen not only becomes alive but sensitive inside the Earth; and this is of the greatest importance for agriculture. Nitrogen becomes the bearer of that mysterious sensitiveness which is poured out over the whole life of the Earth. (Steiner 2007:25)
If we have any feeling or receptivity for these things, we can observe the process most wonderfully in the papilionaceae or leguminosae — in all those plants which are well known in farming as the nitrogen-collectors. They indeed have the function of drawing in the nitrogen, so to communicate it to that which is beneath them. Observe these leguminosae. We may truly say, down there in the Earth something is athirst for nitrogen; something is there that needs it, even as the lung of man needs oxygen. It is the limestone principle. Truly we may say, the limestone in the Earth is dependent on a kind of nitrogen-inbreathing, even as the human lung depends on the inbreathing of oxygen. These plants — the papilionaceae — represent something not unlike what takes place on our epithelial cells. By a kind of inbreathing process it finds its way down there. (Steiner 2007:27)
The point is how to make use of this property in the right way. The influence of the astral on the nitrogen is marred in the presence of an all-too thriving ethereal element. Hypertrophy of the ethereal in the heap of compost does not give the astral a chance, so to speak. Now there is something in Nature, the excellence of which for Nature herself I have already described to you from several standpoints, and that is the chalky or limestone element. Bring some of this perhaps in the form of quicklime — into the heap of compost, and you will get this result: Without inducing the evaporation of the astral over-strongly, the ethereal is absorbed by the quicklime, and therewith oxygen too is drawn in, and the astral is made splendidly effective. (Steiner 2007:34)
This is an indication, pointing to such measures as we on our part may recommend for the purpose of still further enhancing the effectiveness of what is used as ordinary farm-yard-manure. What is farm-yard-manure? It is what entered as outer food into the animal, and was received and assimilated by the organism up to a certain point. It gave occasion for the development of dynamic forces and influences in the organism, but it was not primarily used to enrich the organism with material substance. On the contrary, it was excreted. Nevertheless, it has been inside the organism and has thus been permeated with an astral and ethereal content. In the astral it has been permeated with the nitrogen-carrying forces, and in the ethereal with oxygen-carrying forces. The mass that emerges as dung is permeated with all this. (Steiner 2007:34)
STEINER, Rudolf. 2007. The Agriculture Course. (Trans.: George Adams) Shrewsbury: Wilding & Son Ltd.