LIME CORRECTS SOIL ACIDITY 65 



three principal fertilising matters, phosphoric acid, 

 potash, and ammonia. Lime actually adds none of these 

 three elements to the soil, so that its repeated application 

 tends to impoverish the soil. Lime should never be mixed 

 with or applied at the same time as manure containing 

 a salt of ammonia, as it acts at once on the salt and 

 liberates the ammonia too quickly. 



Applications of lime are particularly beneficial for 

 neutralising the acidity present in sour soils, and for 

 this purpose it should be broad-casted as powdered 

 slaked-lime, at the rate of 2,000 Ib. per acre. Sea sand, 

 rich in shells, often contains as much as 30 per cent, of 

 lime ; wood ashes contain from 30 to 35 per cent, of 

 lime, and either of these materials could be advantage- 

 ously substituted for lime where the latter is expensive. 

 The lime in these materials is, however, not free, but 

 exists as carbonate, which is usually as effective as 

 lime itself. 



