Artificial Manures

Abstract

THOSE who take up this volume with the hope of finding the chemistry of artificial manures fully treated will be much disappointed. Not only are many of the commonest manures scarcely mentioned, but some of the most important and practical aspects of the subject are never noticed. The behaviour of manures after they come in contact with the soil is surely of the greatest importance. Chemical investigations have long ago proved that some of the ingredients of manure—as phosphoric acid and potash—are firmly held in combination by the soil, while others—as nitric acid, chlorine, and soda—are feebly retained, and readily pass away in the drainage water after rain. It has also been abundantly proved that though ammonia is firmly retained by a fertile soil, it rapidly undergoes conversion into nitric acid, which is easily washed out. The practical conclusion from these facts is plain. Diffusible manures must be applied only when the crop can make immediate use of them. Now, though M. Ville speaks voluminously concerning the application of phosphates, nitrates, and ammonium salts, no reference to the facts just indicated is to be found in his book, beyond the mere statement that clay is capable of temporarily retaining potash and ammonia.

On Artificial Manures, their Chemical Selection, and Scientific Application to Agriculture.

A Series of Lectures given at the Experimental Farm at Vincennes, during 1867 and 1874–5. By M. Georges Ville. Translated and Edited by W. Crookes, F.R.S. (London: Longmans and Co., 1879.)