16 



Or, if ir is wished, the experiment may be made more complicated, 

 as follows : 



Plot No. I. — Check. No fertilizer. 



" II. — 160 pounds of nitrate of soda. 



" III. — 160 " muriate of potash. 



" IV. — 320 " superphosphate. 



V.— Check. No fertilizer. 

 " VI. — 160 pounds nitrate of soda. 

 320 " superphosphate. 

 VII. — 160 " nitrate of soda. 



160 " muriate of potash. 

 " VIII. — 320 " superphosphate. 



160 " muriate of potash. 

 " IX. — 160 " nitrate of soda. 



160 " muriate of potash. 

 320 " superphosphate. 

 X. — Check. No fertilizer. 



The amount of the fertilizers given are, in every case for an acre; 

 but they are not intended to represent the quantities of these materials 

 which should be used for various crops. That point will be arrived at as 

 a result of the experiments. The application of the potash and super- 

 phosphate should be made broadcast before planting, preferably some 

 weeks before. The nitrate is very soluble, and is easily leached from the 

 soil, consequently, it is best applied in two or three applications, one at 

 time of sowing seed, and the' other two at intervals of three or four 

 weeks. In every case, the fertilizers should be evenly distributed over 

 the ground. The above mentioned quantities provide for one pound or 

 multiple thereof per square rod. 



Careful notes should be made on the increased cost of production, 

 the appearance and quality of the crop, and the weight of the products 

 of the different plots should be determined, and the whole data used as 

 a basis of comparison. As interest in the work increases, further- ex- 

 periments may be made with different quantities of these materials and 

 with other fertilizers. 



In these fertilizer experiments it may also be well to introduce lime 

 into one or two of the plots, in order to determine whether this substance 

 is needed either to correct acidity or to make other useful compounds 

 available. Further, it would be good practice to include in the number 

 of plots indicated one or two in which the cultivation of the soil was 

 made more perfect, the object being to see whether the need is for more 

 plant food or better cultivation. 



All these experiments have a much wider scope than the simple find- 

 ing out of the deficiencies of the soil. They are educative, as they en- 

 courage close observation and exact methods of work, and give the ex- 

 perimenter an opportunity to familiarize himself with the materials used 

 as fertilizers. 



