Nitrogenous Manures 



nitrous vapours which cause a loss of nitrogen. 

 Often farmers say that, after spreading nitrate in a 

 dry season, the nitrate attracts to itself the mois- 

 ture in the soil, forming round the grains of nitrate 

 an aureole saturated with a solution of nitrate which 

 destroys the plants with which it comes in con- 

 tact, and, on the other hand, forms a zone of 

 abnormally dry soil in which the plants suffer greatly 

 from drought. Then do not spread nitrate when the 

 soil is not sufficiently moist or when rain is not 

 expected. 



The soil has no power to retain the nitrates 

 and the superfluous water drains them away. That 

 is why it is always advisable not to give large doses 

 and always to make two applications if possible. In 

 summer time, however, the evaporation of the water 

 of the soil will always be sufficient to prevent this 

 wasting. A well-known action of nitrate is that 

 it keeps a freshly turned soil damp, and makes a 

 dry soil cool, to such an extent that in dry years the 

 use of nitrate at the right season will have a very 

 beneficial effect, the nitrate rendering the soil less 

 permeable and to some extent preventing evapora- 

 tion. 



Nitrate of soda being the most active and rapid 

 of all nitrogenous manures is quickly utilised by 

 the plants, and in the spring on wheat crops dis- 

 coloured by an excess of moisture during the winter 

 the results become noticeable within two or three 

 days in a fresh verdant colour. The addition of 

 nitrate, which is often at a minimum in the soil, 

 enables the farmer ordinarily to obtain a notable 

 increase of crops ; but the results fall off rapidly 



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