THE ANALYSIS 121 



wide across the field. Each trial strip or plot should have a dis- 

 tinct treatment and one should be left unfertilized as a check 

 plot for comparison with the others. In fertilizing a crop of wheat 

 one strip may be fertilized with a given amount of acid phosphate, 

 another with rock phosphate (floats). Another may have one of 

 these fertilizers with the addition of some muriate of potash, and 

 perhaps another with a little nitrogen added. Still another may 

 have a supply of lime with or without the other fertilizers. It is 

 often well to compare the chemical fertilizers with barnyard 

 manure. This can easily be done by applying manure alone to 

 one, and manure with lime to another plot. 



During the growth, and as the crop matures, the farmer may 

 determine well which treatment has benefited the crop most. It 

 may not be profitable for the farmer to make actual weights of 

 the yields, but that may be left to State Experiment Stations. 

 In most states the soils vary so widely in their characteristics that 

 it is important that the soil on each farm be tested in such a 

 manner. The farmer who does such work will improve his method 

 more rapidly than by simply studying the results in some other 

 part of the state. 



Buying Fertilizers. There are several different problems in- 

 volved in the purchase of commercial fertilizers. Since laws have 

 been passed controlling their sale some of the difficulties have 

 been overcome. In most states it is still impossible to determine 

 the source of ingredients from which the nitrogen, phosphoric acid 

 and potash are derived. A number of the state laws require that 

 the source of the phosphoric acid and the potash be indicated, but 

 few if any of them require that the source of the nitrogen content 

 be published. Fortunately changes in state laws regarding this 

 are gradually being made. At present comparatively few buyers 

 know the real nature of the numerous preparations which are 

 offered for sale every year under special brand names. These 

 names are not permanent or do not represent an unchangeable 

 composition in the fertilizer sold under the name. Usually the 

 name is meaningless, if not actually misleading. ' 'Brown's Truck 

 Grower" may not be suited to all truck growers, and indeed may be 

 very badly suited to certain soil conditions and special truck crops. 



The analysis is usually required by law to be printed upon 

 the tag or upon the bag containing the fertilizer. This -analysis 

 should be studied very closely by a man who has power to elimi- 

 nate the non-essentials, as much is usually added which tends to 



