344 ANALYSES OF NOVA SCOTIAN SOILS HARLOW. 



Phosphoric Acid. 



The total phosphoric acid of the soil exists in a much 

 more easily soluble form than the total potash; the acid 

 soluble phosphoric acid is the total and is found in our soils 

 as shown in the summary, Table 4. The phosphoric acid is, 

 as shown in Table 5, about one-fourth available and there- 

 fore soon used either by the plant, or washed away as a 

 sediment. 



LIME AND ACID SOILS. 



Comparing the percentage of the important constituents 

 with standards given, one notices the deficiency of lime. 

 The lime, CaO, shown in the hydrochloric acid extract may come 

 from dissolving the limestone or the lime silicates; since lime- 

 stone cannot exist in the presence of acids we are led to test 

 soils for acidity. 



Acid Soils. 



A simple test. for an acid soil is: Place a lump of damp 

 soil on a piece of moistened blue litmus; a reddening shows 

 the presence of acid. Out of sixty-eight soils from upland, 

 intervale, and marsh so tested, only ten showed no acid 

 reaction and of these, six were new marsh deposits; the four 

 only, cultivated soils showing no acid reaction were from areas 

 giving good crops, in one case four tons of hay per acre. 

 Many of the acid soils were from unused fields and some from 

 geological areas showing much limestone rock. Now lime 

 and limestone are the substances which will correct the acidity 

 so we are, from this test, led to infer that our soils need 

 additions of lime. The action of this substance in the soil 

 is very complex and but imperfectly understood. 



Since Nova Scotia has many limestone areas, one might 

 expect the soil to be well provided with lime, but such is not 

 the case; it being a land of hills and valleys, of brooks and 

 rivers, the limestone is carried away especially from the light 

 soils of the limestone areas. From the limestone soils of 



