Possibilities of the Soil 



Now, in order to increase the crop, it will be of 

 no use to raise the nitrogen plank, or the height of 

 the water in the tub, because the crop is regulated 

 by the height of the plank of K2O. But, raise the 

 plank of K2O and immediately the crop will be 

 increased in proportion to that rise. Adding to 

 the plank of nitrogen would not increase the crop 

 at all. One would merely have spent money use- 

 lessly. 



But from the moment that the plank of KoO 

 has passed the plank of P2O5, the increase of K2O, 

 as far as the level of the capacity of the soil will 

 not further increase the crop, because the P2O5 

 is not in the requisite proportion. This plank also 

 must be raised to the height of the capacity of the 

 soil. It is at this stage that the best results can be 

 expected under the given conditions. It is the strict 

 application of the Law of the Minimum which enables 

 us to put waste lands into cultivation economi- 

 cally. 



Each kind of crop has different needs and demands 

 different quantities of manure. Therefore, knowing 

 the requirements of a crop and the elements which are 

 lacking in the soil, one can easily determine the re- 

 spective quantities of the various manures to use, 

 and give them in the necessary quantities when the 

 requisite proportions have been decided. But there 

 is a limit to the 



Possibilities of the Soil. 



Manures cannot be apphed indefinitely in the 

 hope of getting a corresponding increase in crops. 

 In spite of using good proportions, there would come 



n 



