CYAN AM ID — manufacture:, CHEMISTRY AND USES 87 



about the destruction of the mustard within a few days. The 

 application is made when the mustard plant is young, best 

 when it has only four or six leaves. The more leaves it has 

 the more lime-nitrogen will be required. The grain crop may 

 be affected a little immediately after the application, and may 

 turn somewhat brown at the tips of the leaves, but it will 

 quickly recover and become much greener than the grain in 

 untreated fields. The leaves of the grain crops, especially oats, 

 stand almost vertical and are comparatively smooth and waxy, 

 so that very little lime-nitrogen clings to them and no 

 permanent damage is done. Practically, this method of de- 

 stroying wild mustard is quite economical, since the nitrogen 

 applied in this way seems to have as full fertilizing effect as 

 if it were applied under the crop. The mustard, on the other 

 hand, is practically eradicated. 



DIRECTIONS FOR APPLICATION AS FERTILIZER. 



Very little of the Cyanamid made in this country is applied 

 alone, practically all of it being used as a part of mixed 

 fertilizers. For the guidance of those who wish to use it with- 

 out admixture with other materials, the following suggestions 

 are offered, although it should be recognized that a true test 

 of the efficiency of the Cyanamid used in this country is made 

 only under the conditions in which it is usually applied, that 

 is, as a part of a mixture containing phosphoric acid, potash, 

 and frequently other forms of nitrogen. 



Cyanamid is least efficient when applied as a top-dressing. 

 This is probably due to the quick reaction and fixation in the 

 soil, so that much of the nitrogen is retained in the upper 

 layers of soil where the plant roots do not reach it readily. 

 The application should be made in such a way that the 

 Cyanamid will be buried about where the plant roots are 

 expected to grow. It»should be scattered through the lower 

 layers of cultivated soil as much as possible, so as to favor the 

 greatest spreading of the roots. In the event of a dry season, 

 the larger the root system, the better will be the ability of the 

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