TESTING THE NEEDS OF THE SOIL 155 



the fact that if the experiments are to be of value, and are to show what you 

 want, they must be conducted with the greatest care and accuracy. There 

 must be no guesswork in the measurement of the plats, no guesswork in the 

 weighing of the fertilizers, in the application and complete mixing with the 

 soil, or in the harvesting and weighing of the crop. Guesswork is the bane 

 of much of our American agriculture, and if the farmer is to learn anything 

 from his experiments he must start out with the determination to leave no 

 room for error which it is possible for him to avoid. It is better to make the 

 experiments with some spring planted crop, since some of the articles used, 

 such as nitrate of soda^ may not have its full effect if applied to a fall sown 

 crop. Select a level piece of land which is fairly representative of your farm, 

 and preferably select that which is as nearly as possible the natural condition 

 of the soil and not altered by previous heavy manurings. Lay off accurately 

 a series of plats 204 feet long by 10 feet 8 inches wide. Make ten of these 

 plats and leave an alley four feet wide between each, to prevent the fertilizer 

 from one plat affecting its neighboring plat. It is also important that the 

 whole series be level for the same reason. 



Plats of this size will contain as nearly as practicable, one-twentieth of 

 an acre each. Place firm, stout stakes at the corners of the plats. On the 

 first plat simply prepare the soil thoroughly and apply no fertilizer at all, as 

 this is one of the plats to be used as a comparison. The fertilizer plats are 

 to be numbered as follows: 



Plat No. 1. No fertilizer applied, but same preparation as the rest. 



Plat No. 2. Apply nitrate of soda 8 pounds (160 pounds per acre.) 



Plat No. 3. Apply 16 pounds of acid phosphate (320 pounds per acre.) 



Plat No. 4. Apply muriate of potash 8 pounds (160 pounds per acre.) 



Plat No. 5. Apply no fertilizer at all. 



Plat No. 6. Apply nitrate of soda 8 pounds and acid phosphate 16 

 pounds. 



Plat No. 7. Apply nitrate of soda 8 pounds and muriate of potash 

 16 pounds. 



Plat No. 8. Apply muriate of potash 8 pounds and acid phosphate 16 

 pounds. 



Plat No. 9. Apply nitrate of soda 8 pounds, acid phosphate 16 pounds 

 and muriate of potash 8 pounds, making a complete fertilizer. 



Plat No. 10. Apply no fertilizer. 



The series may be indefinitely extended, and the amounts of each con- 

 stituent doubled or trebled alternately, but the above series will usually suffice. 

 I repeat, that it is necessary to use the utmost care if results of value are to 

 be expected. Get the fertilizers evenly distributed over the whole plat, but 



