152 



Appendix. 



8 Rods Long. 



1 rod wide. 



1 rod wide. 



1 rod wide. 



1 rod wide. 



1 rod wide. 



A set of fertilizer experiments like this last might be made a little more 

 extensive by adding another plat and applying land-plaster or lime. Another 

 plan would be to sow land-plaster or lime upon half of each small experimental 

 plat. In so doing we could ascertain the effects upon the crop of the fertilizers 

 with and without land-plaster or lime. 



If. after the crop has been harvested in the fall, the farmer finds that the 

 yield on the blank plat is about as large as upon the plats that were fertilized 

 then it would be folly to buy fertilizers and apply them to that field. On the 

 other hand, it might be that the plats receiving the nitrate of soda give the 

 largest yield, then the probability is that the field lacks available nitrogen. If the 

 plat receiving barnyard manure gives results far better than any of the commer- 

 cial fertilizer plats, then in all probability the physical condition of the soil 

 needs repairing. The soil needs loosening — needs more decaying oi-ganic matter 

 or humus. 



Many times these fertilizer experiments will answer the questions of the far- 

 mer much better than can a chemist who makes a chemical analysis of the soil. 



A farmer after having determined to his satisfaction which elements of 

 plant-food are beneficial, must next ascertain what quantities can be used most 

 profitably. The fact that the effects of applications of phosphoric acid and 

 potash compounds may extend over more than one year must be taken into 

 account when the value of these fertilizers is considered. Their effects may in 

 some cases be seen upon the following crops for several years. 



When nitrogen in the form of nitrate is applied most of the effect must be 

 obtained the same year, because any nitrate not used by the crop will in most 

 cases leach out of the soil before the succeeding crop is grown. 



Soils Make Plant-Food Insoluble. — When fertilizers are applied to the soil, 

 oven though they contain much water-soluble plant-food, there is but little danger 



