THE SOUTHERN PLANTER. 



645 



The only portion, then, of putrescent 

 manures which, for the time, can nourish 

 ])]ants through their roots, is so much as is 

 soluble in water, and then actually dis- 

 solved; for no matter how much soluble 

 matter may be in manure when applied, 

 it cann jt act as food for plants until rain, 

 or some other source of moisture, pro- 

 duces solution. 



The much larger part of the soluble 

 matter of manures is such as is either 

 solid or liquid. But even if the change 

 be slow enough, such aeriform products 

 may be absorbed by the moisture of the 

 earth, and thus, in solution, be conveyed 

 through the roots to nourish the plants. 

 Water readily absorbs carbonic acid gas, 

 by mere contact ; and ammonia is so easi- 

 ly absorbed, that there may be condensed 

 in water more than seven hundred times 

 its bulk of this highly fertilizing gas. 

 And even after gases, produced by fer- 

 mentation, may have risen, by expansion, 

 above the surface of the manured soil, 

 partially saved by being absorbed and con- 

 densed in dew, and thus conveyed back 

 to the roots. 



But the most important mode by which 

 plants receive carbon as food is in car- 

 bonic acid, from the atmosphere and by 

 absorption through their leaves. This gas 

 is diffused, throughout the atmosphere 

 near the earth, universally and at all 

 times, though in very small proportion, so 

 that it is always present and abundant for 

 the wants of growing plants. Thus it ap- 

 pears that there is no limit to the supply 

 of this essentially necessary food, which, 

 whether obtained through the roots from 

 the earth, or through the leaves from the 

 atmosphere, serves to supply the large 

 quantity of carbon which helps to consti- 

 tute every plant. But though there is no 

 limit to the supply of this food, (carbonic 

 acid gas,) from the atmosphere, and it is 

 thus offered to all plants and in all situa- 

 tions, still there is a strict limit iinposed 

 upon the appetite of plants, or upon their 

 ability to consume and be nourished by 

 this food, and that limit is determined by 

 the constitution of the soil, and the char- 

 acter of the other manures feeding the 

 plant through the roots. 



From all the foregoing preliminary pro- 

 positions or premises, presented in this 

 section, I shall now proceed to deduce 

 the truths which it was the main design of 



this paper to establish ; that is, to deter- 

 mine by which mode of application the 

 fertilizing principles of manure may be 

 best economized, by the largest possible 

 portion being put to use as food for plants, 

 and the least possible suffered to go to 

 waste. 



It has been stated above, that all putres- 

 cent manures, (in whatever stage of the 

 progress of fermentation and decay, and 

 also in the freshest and soundest state of 

 the materials, before fermentation has be- 

 gun,) consist partly of soluble matter al- 

 ready fit to serve as food for plants, and 

 partly of hard, insoluble matter, inert and 

 at that time useless as manure. The pro- 

 portions and quantities of these different 

 parts continually vary in the same body, 

 with the progress of decomposition, by 

 the insoluble parts changing to soluble, 

 and the soluble to the gaseous form, and 

 then passing off, and being lost. Jf ma- 

 nure, whether in its newest and soundest, 

 or in its oldest and most reduced state, or 

 in any int€*rmediate stage of decomposi- 

 tion, be applied to land, and plowed un- 

 der, as is usual, the soluble parts will be 

 dissolved by the first abundant rain. If 

 roots of then growing plants had already 

 spread throughout the soil, and were 

 everywhere present when this solution of 

 the manure took place, they would begin 

 immediately to suck up the liquid food 

 thus offered, and in a few days the whole 

 supply might be put to use, and converted 

 to parts of the plants so fed. But if no 

 plants were yet growing when this solu- 

 tion occurred, then none of this food could 

 be put to such use. If the soil is properly 

 constituted to combine with, and retain 

 such putrescent matter, and also it then 

 requires the supply, it may be so saved 

 until plants are in possession of the sur- 

 face, and demand and will consume the 

 before useless food. But any excess of 

 soluble matter thus furnished, and not con- 

 sumed immediately by plants, and beyond 

 the ability and need of the soil to combine 

 with and fix — and also all subsequent sup- 

 plies under like circumstances — would be 

 subject to further decomposition, and final- 

 ly to entire waste in the gaseous state. 

 Some parts, while yet in the condition of 

 solids dissolved in water, would pass off 

 from the land with the excess of rain 

 water, and flow into the brooks and rivers. 

 Other parts would sink through the pervi- 



