Manuring 305 



to apply half the quantity given in the various 

 formulas every year, instead of the larger 

 dressing every other year. 



The principal artificial substance on the 

 market to replace nitrogen is the well-known 

 Chili saltpetre or nitrate of soda, which contains 

 nitrogenous constituents in a high degree (over 

 15 per cent.). It must not, however, be applied 

 in large doses at one time, but in small doses, so 

 that it can be easily absorbed, as- the soil does 

 not retain it for any length of time. The great 

 advantage of nitrate of soda lies in its being in 

 a form of nitrogen which is immediately avail- 

 able to the plant, so that it becomes assimilated 

 in a few days. 



Some planters, whilst acknowledging their 

 preference for nitrate of soda, complain of its 

 tendency to attract moisture, which not only 

 tends to deteriorate the nitrate itself, but any 

 other fertilizer mixed with it as well. This 

 should not be, and the fault lies with the user. 

 Materials like cement, manures, &c., and 

 especially nitrate of soda, should always be 

 carefully stored away in a thoroughly dry place ; 

 if this be done, no trouble will be experienced. 

 Out in the open, especially in times of drought, 

 this very quality of nitrate of soda is one of its 

 great advantages, for when mixed with a mulch 

 it helps to increase the moisture available for 

 the soil. In semi-arid regions the addition of 

 sodium nitrate is stated to have actually shown a 

 reduction in the need for water of some 30 per cent. 



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