"Dry mixed" or shovel-mixed goods are those which are 

 prepared by mixing the crude ingredients together — for ex- 

 ample, the mixing of ground bone, ground phosphate rock or 

 dry acid phosphate with tankages, etc. Such a mixture is 

 purely a mechanical union in which no chemical action takes 

 place. We can make a dry mixture of lime and sand, but the 

 moment we add water, chemical action sets in and we have 

 mortar, which is quite another material. Flour and water and 

 a little salt could be mixed up and served as food, but it would 

 not be bread. It is simply dough, not cooked bread which 

 is palatable and digestible. Chemically made fertilizers, like 

 properly made bread, are the prepared food or bread of 

 plants, and are as superior to "dry mixed" or shovel-mixed 

 fertiUzers as bread is superior to the crude grains from which it 

 is made. Now the chemical process of making fertilizers is 

 the outcome of long experience in the chemical fertilizer in- 

 dustry, which seeks to render, and actually does render, prac- 

 tically all the plant food available for plants, as the cooking of 

 meats and vegetables renders them available for man. 



Processes vary in treating by-products which contain plant 

 food. In some cases the processes are so conducted as to take 

 out all the grease and leave the by-products in a hard, unavail- 

 able condition. In other cases they are so conducted that, 

 while most of the grease is extracted, the product is left 

 in a soft, available condition. It depends largely upon the 

 apparatus used and the temperature employed. Everyone 

 knows that beefsteak can be cooked in a way that will leave it 

 very indigestible, or it can be served tender and juicy and easily 

 digestible. 



There are forms of nitrogen in the market which are more 

 or less inert, including many so-called tankages or bloods, which 

 are dried and ground, either separately or mixed with good tank- 

 age or dried blood, and sold to dry mixers or home mixers as 

 tankages, much as a little cream used to be mixed with oleo- 

 margarine to give it the aroma and taste of butter. These, if 

 only "dry mixed," while giving goods that may show up well 

 in the laboratory, do not show up well in the field, for they have 

 not been properly cooked, as it were; and after all, it is the field 

 test which tells the story. The practical farmer who is growing 

 quick crops for quick returns wants goods that will act during 



19 



Mechanical 

 Not a 

 Chemical 

 Union 



Difference 



in 



Processes 



Good and 

 Poor 

 Forms of 

 Nitrogen 



