114 Practical Farming 



seed meal, fish scrap, or tankage, which will become avail- 

 able during the growth of the crop and will thus keep up 

 the feeding of the crop. Phosphoric acid can be gotten 

 most cheaply in acid phosphate or the dissolved phosphatic 

 rock, and potash can be had best and cheapest in the muri- 

 ate of potash imported from Germany. Knowing, then, 

 the percentage of nitrogen, phosphoric acid, and potash 

 contained in each of the materials, it is easy to make up 

 a complete fertilizer suited to the various crops and soils. 



While one's soil needs can only be ascertained by the 

 man who cultivates it, the chemist, however, can tell you 

 what your soil contains, and you may have a soil that the 

 chemical analysis shows contains large amounts of all 

 the elements of plant food, and yet it may be a very 

 unproductive soil by reason of the unavailabihty of these 

 things. Actual experiments on the soil itself are necessary 

 to determine what it particularly needs in the way of 

 fertihzers. Professor Voorhees, in his work on FertiHzers, 

 suggests that the farmer stake off ten plots, each one- 

 twentieth of an acre, and gives the following plan: 



Plot I. Check. No Fertilizer 



Plot II. Nitrate of Soda 8 pounds. 



Plot III. Superphosphate (Acid Phosphate) . i6 pounds. 



Plot IV. Muriate of Potash 8 pounds. 



Plot V. Check. No Fertilizer 



Plot VI. Nitrate of Soda 20 pounds. 



Acid Phosphate 16 pounds. 



Plot VII. Nitrate of Soda 20 pounds. 



Muriate of Potash 8 pounds. 



Plot VIII. Acid Phosphate 40 pounds. 



Muriate of Potash 8 pounds. 



Plot IX. Nitrate of Soda 8 pounds. 



Muriate of Potash 8 pounds. 



Acid Phosphate 16 pounds. 



Plot X. No FertiUzer 



