1 86 SOILS. 



leached of its lime content, and is consequently extremely un- 

 thrifty. 



Woodlands of northern countries bearing beech and oak are 

 especially apt to be benefited by the action of lime on the 

 " raw," acid humous soil and underlying hardpan, which is 

 commonly underlaid by a leaden-blue sandy subsoil ("Blei- 

 sand " of the Germans, " Podzol " of the Russians) colored 

 brown by earth humates and mostly too moist in its natural 

 condition to permit of adequate aeration. These soils are 

 usually of but moderate fertility, and are best suited to forest 

 growth unless somewhat expensive methods of improvement 

 can be put into practice. 



" Plowsole." An artificial hardpan is very commonly 

 formed under the practice of plowing to the same depth for 

 many consecutive years. The consolidated layer thus created 

 by the action of the plow (hence known as plowsole) acts 

 precisely like a natural hardpan, and is sometimes the cause of 

 the formation of a cemented subsoil crust simulating the nat- 

 ural product. This is most apt to occur in clayey lands, and 

 greatly increases the difficulty of working them, while detract- 

 ing materially from the higher productiveness commonly at- 

 tributed to them as compared with sandy lands. Of course it 

 is perfectly easy to prevent this trouble by plowing to different 

 depths in consecutive years, and running a subsoil plow from 

 time to time. In this case, also, lime will generally be very 

 useful and be found to aid materially in the disintegration of 

 the " plowsole." 



It is hardly necessary to insist farther upon the need of the 

 examination of land to be occupied, for the existence of hard- 

 pan or other faulty subsoil, which may totally defeat for the 

 time being the farmer's efforts, or make him lose his invest- 

 ment in plantations after a few years. Probing by means of 

 the steel rod described above (p. 177) or boring with a post- 

 hole auger; or finally, if necessary, digging a pit to the proper 

 depth (from four to six feet in the arid region), should 

 precede every purchase of new or unexplored agricultural 

 land. 



Marly Substrata. Among the causes of failure occasionally 

 found in the case of the " going-back " of orchards, is the 



