3i 6 SYSTEMS OF PERMANENT AGRICULTURE 



cannot be obtained cheaply. It is worth over $2 a pound, and nobody would 

 think of recommending it as a fertilizer. . . ." 



"There has not been a publication on the subject of soil fertility going out 

 from the Bureau of Soils and I think I can speak advisedly, for every one 

 has gone through my hands in which we did not have the experimental proof 

 long before the publication went out, and that this is being recognized I think 

 I can claim by the fact that a number of agrkultural colleges in the country 

 are using our bulletins as text-books. I have recently come from a lecture 

 trip extending from Louisiana to Michigan, and I found everywhere that this 

 is being taught, and, as I say, our publications are being used for text-books." 



On page 5 of Farmers' Bulletin 257, Professor Whitney makes 

 the following statements: 



"I shall be glad, however, to speak of certain general features of the essential 

 and broadly applicable laws of soil fertility that the Bureau of Soils, with its 

 large force of field men and its large force of chemists and soil physicists, has 

 investigated in the last twelve years. We think that as a result of this work 

 we understand far more of the principles of soil fertility now than we ever have 

 before, and I wish to give the results in words as simple as possible. You need 

 not necessarily believe everything I say (because I cannot say truly that I 

 believe everything myself, but only that our opinions seem reasonable deduc- 

 tions)." 



In general, the soil fertility theories of Whitney and Cameron 

 may be briefly summarized in the following statements, all of 

 which are direct quotations: 



1. "It appears further that practically all soils contain sufficient plant food 

 for good crop yields, that this supply will be indefinitely maintained, and that 

 the actual yield of plants adapted to the soil depends mainly, under favorable 

 climatic conditions, upon the cultural methods and suitable crop rotation." 



WHITNEY and CAMERON, in Bureau of Soils Bulletin 22, page 64. 



2. "In all soils there are rock particles or minerals containing phosphoric 

 acid and potash, and in all the soil solutions that we have ever examined 

 and we have examined hundreds of them from all parts of the country you 

 will be astonished to learn that the composition and concentration of the soil 

 moisture, which is the nutrient solution spread throughout the surface 

 soil of the earth for plants to grow in and to gather their food from, 

 you will be astonished to learn that the concentration of this soil moisture is 

 sensibly the same whether we examine your sandy truck soils on your river necks, 

 your sandy clay wheat soils on the uplands, the Hagerstown clay in the valley 

 of the Shenandoah, or the black prairie soils of the West. These minerals 

 are contributing to the solution in which the plant feeds. As I have said, these 

 minerals are difficultly soluble, but they are appreciably soluble. They are 



oluble enough to maintain a solution which is amply sufficient for the plants to 



