Note 212 — Chapter X · SULPHATE OF AMMONIA.

From experiments by Lehmann and others with buckwheat and maize, it would seem that certain plants may prefer, at certain stages of their growth, ammonia to nitrates. In the case of maize, ammonia may be preferred in the early stages of growth, while nitrates are preferred as it becomes more mature. In view, however, of our present knowledge of nitrification, it may well be doubted whether the conclusions arrived at from Lehmann's experiments can be accepted.