Fertilizers 7 



muriate of potash, nitrate of soda ; or by some trade name, 

 as kainit, blood and bone, guano. 



The fertilizer formulae employed in this book should not 

 be regarded as the best under all varying soil conditions. 

 They are suggestive of what will probably prove advan- 

 tageous imder average or normal conditions in a sandy soil. 

 Experience with any particular field or region will soon in- 

 dicate what changes should be made in a formula for a par- 

 ticular crop. Generally speaking, starch-producing crops, 

 such as Irish potatoes and sweet potatoes, will be bene- 

 fited by a large quantity of potash. 



SOTIRCES OF NITROGEN 



In its natural state, nitrogen occurs as an atmospheric 

 gas, and as such it is not available as a fertilizer. When 

 the amount of nitrogen is mentioned in speaking of a 

 fertilizer, one simply means that it is in some combination 

 with other elements that hold it in the form of a solid. 



The different forms in which nitrogen occurs as a ferti- 

 lizer are : first, as organic matter, either vegetable or ani- 

 mal, for example, cottonseed meal, fish scrap, dried blood, 

 tankage ; second, as nitrate, in nitrate of soda, or nitrate 

 of potash ; third, in the form of ammonia compounds, as 

 sulfate of ammonia. In the guarantees or analyses of 

 fertilizers, when the amount of nitrogen is given, it is in- 

 tended to imply how much of it would be present if it were 

 in the form of a gas. Sometimes the amount of nitrogen 

 in a fertilizer is expressed as ammonia, when it is really 

 nitrate or organic matter. It is calculated in this way for 

 ease in comparison. This is the method used in Florida. 



