THE MONTHLY BULLETIN. 410 



Cemented Soils. 



Ilardpan — natural or induced — is all too common, and there is no 

 greater l)ar to success in the orchard. The natural hardpan can be 

 broken up by blasting with dynamite. The developed hardpan is 

 caused by lime in the irrigating water and is often called "plow-sole," 

 as it occurs just beneath tne plane of cultivation. A more suitable 

 name is "irrigating hardpan," as it is usually caused by the lime cement 

 in the water used in irrigation. The Avater, as it comes from the rocks, 

 is saturated with bicarbonate of lime. This is very soluble, but as it 

 enters the soil it becomes reduced to carbonate of lime as the water 

 evaporates, and the less soluble carbonate cements the soil into the 

 so-called plow-sole or irrigating hardpan, Mdiich, of course, must form 

 just where the greatest evaporation occurs or just at the level of the 

 cultivation limit. In dry seasons and late in the season this cement is 

 most in evidence. In seasons of heavy Avinter rains this cement or 

 hardpan may entirely disappear. 



This artificial hardpan is entirely too common. It is the cause of much 

 of the chlorosis and ill health of the trees. It may be that dieback often 

 owes its presence in our orchards to this cementing of the soil. That it 

 would foster gummosis and other bacterial and fungoid attacks is more 

 than probable. Early deep cultivation and cultiA^ating at varying 

 depths through the season Avill aid to break up and prevent this 

 impervious formation. It is quite common uoaa' among many of our 

 best orchardists to use the subsoiler during the season to break through 

 this cemented stratum of soil. Early deep cultivation will often prevent 

 its formation. 



Alkali. 



There are two soil salts that are knoAvn as alkali — carbonate and sul- 

 phate of soda. The first is black alkali ; the other, white alkali. Both are 

 quite readily soluble and present in small quantities in most all rocks and 

 so are conveyed in very minute quantities in most all running water 

 Avhich flows from the rock strata of the earth. 



In low, poorly drained sections — usually clay basins — these salts are 

 often present and harmful. Black alkali is much the more serious. It 

 takes its name from the fact that earth containing it in the presence of 

 humus is very black in color. Sowing gypsum on such land tends to 

 change the black to the much less injurious white alkali. Thorough 

 drainage and plenty of water Avill Avash out the alkaline salts and restore 

 the fertility of the land. 



This explains why arid soils are much more likely to be alkaline than 

 are those in humid regions. It remains to be said that some crops are 

 far more tolerant of black alkali than are others. 



In purchasing land every one should examine closely to find whether 

 alkali and hardpan are present. If either occur in very limited areas this 

 would be no bar to making the purchase ; if in considerable abundance, 

 one better think twice before procuring such land for ranch purposes. 



