MANURES 43 



(6) Partially general manures are nitrate of 

 lime and nitrolim, both of which supply both 

 nitrates and lime. Basic slag, though usually 

 regarded as a phosphatic manure, really 

 belongs to this class, as it contains lime. 

 Bones also contain small quantities of the 

 other substances. 



Some of the manures perform other duties 

 as well as those indicated above. For example, 

 the soda of nitrate of soda helps, by chemical 

 reaction, to bring into use unavailable potash. 

 Lime is the best check for insect attacks and 

 plant diseases we have, also for sweetening 

 sour land, for breaking down clays, and for 

 converting nitrogenous vegetable and animal 

 matter in the soil to available nitrates. Farm- 

 yard manure, if applied when fresh to heavy 

 soils, opens them up by admitting air, and if 

 applied when well rotted to light, sandy soils it 

 gives them *'body," and a greater capacity to 

 hold water and therefore plant-food. 



The basis of all manuring is farmyard 

 manure, and all other manures are to be 

 regarded purely as supplements to it. Farm- 

 yard manure is produced on every farm, and as 

 it cannot be allowed to accumulate it must be 



