PROPORTIONS OF NITROGEN, ETC., IN PEAT. ---------+-------------+------------+------------+---------+------------ | | | Total |Ammonia, | | | Analyst. | Nitrogen. |per cent.|Nitric acid. ---------+-------------+------------+------------+---------+------------ 1--Brown | | | | | Peat|Air dry (?) |Boussingault| 2.20 | 0.018 | 0.000 2--Black | | | | | Peat| " | " |Undetermined| 0.025 |Undetermined 3--Peat |Dried at 212°|Reichardt[4]| " | 0.152 | 0.483 4--Peat | " | " | " | 0.165 | 0.525 5--Peat | " | " | " | 0.305 | 0.241 6--Peat | " | " | " | 0.335 | 0.421 ---------+-------------+------------+------------+---------+------------
Specimens 3, 4 and 5, are swamp (or heath) mucks, and have been weathered for use in flower-culture. 3 and 4 are alike, save that 3 has been weathered a year longer than 4. They contain respectively 41, 56 and 67 _per cent._ of organic matter.
Sample 6, containing 86 _per cent._ of organic matter, is employed as a manure with great advantage, and probably was weathered before analysis. It contained 85 _per cent._ of organic substance.
More important to us than the circumstance that this peat contains but little or no ammonia or nitric acid, and the other contains such or such a fraction of one _per cent._ of these bodies, is the grand fact that all peats may yield a good share of their nitrogen to the support of crops, when properly treated and applied.
Under the influence of Liebig's teachings, which were logically based upon the best data at the disposal of this distinguished philosopher when he wrote 25 years ago, it has been believed that the nitrogen of a fertilizer, in order to be available, must be converted into ammonia and presented in that shape to the plant. It has been recently made clear that nitric acid, rather than ammonia, is the form of nitrogenous food which is most serviceable to vegetation, and the one which is most abundantly supplied by the air and soil. The value of ammonia is however positive, and not to be overlooked.
When peat, properly prepared by weathering or composting, is suitably incorporated with a poor or light soil, it slowly suffers decomposition and wastes away. If it be wet, and air have access in limited quantity, especially if _lime_ be mixed with it, a portion of its nitrogen is gradually converted into ammonia. With full access of air _nitric acid_ is produced. In either case, it appears that a considerable share of the nitrogen escapes in the free state as gas, thereby becoming useless to vegetation until it shall have become converted again into ammonia or nitric acid. It happens in a cultivated soil that the oxygen of the air is in excess at the surface, and less abundant as we go down until we get below organic matters: it happens that one day it is saturated with water more or less, and another day it is dry, so that at one time we have the conditions for the formation of ammonia, and at another, those favorable to producing nitric acid. In this way, so far as our present knowledge warrants us to affirm, organic matters, decaying in the soil, continuously yield portions of their nitrogen in the forms of ammonia and nitric acid for the nourishment of plants.