92 DEPARTMENT OF AGRICULTURE GEORGIA. [378] 



decomposition of vegetable matter, and the increased sol- 

 ubility of mineral compounds. 



It prevents the formation of acid compounds, poisonous 

 to vegetation. 



It facilitates the preparation and cultivation of the soil, 

 and largely increases its productive capacity. 



Subsoiling and deep plowing accomplish some of these 

 ends, but act better in conjunction with under-draining. 



Each landowner, however, must determine for himself 

 whether his soil is of such a character as to be sufficiently 

 benefitted by drainage and subsoiling to justify such an in- 

 vestment of time, labor, and capital. The natural drainage 

 of many of our soils is sufficient for agricultural purposes, 

 and no land without a compact (generally clayey) subsoil 

 will be materially benefitted by sub-soiling. Its propriety 

 will depend also upon the chemical composition of both soil 

 and subsoil. This may, to some extent, be determined 

 by chemical analysis, of which Prof. Hilgard, in the Agri- 

 cultural Report of Mississippi, says : 



" Analysis teaches us what are the kinds and respective 

 quantities of the ingredients contained in crops, soils, and 

 manures. It teaches us, therefore, which of the latter two 

 will be best calculated to promote the successful culture of 

 the former ; to obtain which knowledge by mere exper i- 

 menting, would require a disproportionate amount of time 

 and labor. The absence of a single one of the ingredients 

 necessary for the growth of a plant renders unavailing the 

 presence of all the rest. Unless we are taught by analysis 

 which ingredient or ingredients, of which there is a defi- 

 ciency, we shall be compelled, in order to be safe, to add 

 all of them, at great and unnecessary expense ; for it will 

 be of no practical advantage to have added an additional 

 supply of those of which there is no lack. 



"The importance of reliable analysis of crops, soils and 

 manures is, therefore, obvious enough ; yet the mere pres- 

 ence of any useful ingredient in a soil or manure, as de- 



