FARM-YARD MANURE. 123 



47,) yields in its decay carbon, which, provided 

 it takes place under the ground or in or near 

 situations where other plants are vegetating, 

 is at once absorbed by them and assimilated in 

 their growth ; but if this decay is allowed to 

 take place, as too frequently is the case, in situ- 

 ations where its carbon cannot be assimilated, 

 then such carbon is entirely lost. 



Animal excrement, urine, for instance, the 

 principal ingredient in farm-yard manure, 

 yields nitrogen, and both these substances, the 

 nitrogen and carbon, are of primary impor- 

 tance in the growth of plants. It is, therefore, 

 a question of considerable importance, how 

 both these substances, arising from the decay 

 of vegetable and animal matter, can be so pro- 

 duced, that all shall be absorbed and none be 

 allowed to pass off in the gaseous state to the 

 atmosphere. How, indeed, all may be saved 

 and no part wasted? The query then is, how 

 is this desirable arrangement to be produced ? 

 If straw, for instance, mixed with animal ex- 

 crement were applied to the land in its fresh 

 state, and then to be ploughed in, there can be 

 no doubt but that all the carbon it may contain 

 would be absorbed by the soil and none would 

 be lost; but against this it may be fairly stated, 

 that the time such straw would require for its 

 decomposition, would render its effect in some 

 measure useless, as the carbon yielded is prin- 

 cipally necessary to plants in the early stage 

 of their growth, when a rapid supply is neces- 

 sary ; and which, in this latter case, certainly 

 would not be the case; but if, as is too fre- 

 quently the case, the stable litter and other 



