FORTY-SECOND ANNUAL REPORT. 137 



usual forms of plant-food. Then again, some of the injurious compounds 

 formed in the soil appear to be less injurious in the presence of nitrates, 

 phosphates and potash; with some, nitrate gives the best results, with 

 others phosphate and with still others potash has the most influence in 

 overcoming the injurious effects. So it is seen, that the fertilizer have 

 a value, when added to the soil, in addition to their plant-food value. 



This new view of soils is well expressed in the following words of 

 Dr. Schriener: "The soil cannot be considered as the dead, inert re- 

 mains of rock and previous vegetation, but must be considered as an 

 accumulation of such material in which the process of formation, alter- 

 ation and transposition are still at work. In other words the soil in 

 its entirety is not dead or inert, but endowed with functions analogous 

 to those of life itself. In it take place the same processes of solution 

 and deposition that have taken place in past ages, and are taking place 

 today in the geologic processes connected with the action of the water 

 on the rocks and minerals of the earth's crust. In it take place the 

 same physical and chemical interactions as take place in the movement 

 of subsurface waters generally, resulting in ore formations and deposi- 

 tions. In it take place the same processes of fermentation, digestion, or 

 decay of organic materials as take place in animals and* plants or in 

 the production of industrial products, such as cheeses, wines and beers, 

 brought about in the soil as in these other processes by means of fer- 

 ments, bacteria and fungi or molds. In it take place the same processes 

 of oxidation and reduction which play so important a part in all life 

 processes and it has been shown that the nature of the compounds in the 

 soil organic matter is the same as those derived from similar laboratory 

 processes of digestion, oxidation or reduction. Organic matter is very 

 changeable; it is the material which forms the food, as it were, of all 

 the microorganisms of the soil, of the bacteria, of the molds, etc., and 

 influences them favorably or unfavorably, just as the higher plants are 

 affected. In turn these agents are great promoters of these changes 

 in the organic debris of the soil. All of these processes and life forms 

 in the soil are affected bv fertilizer salts when added to the soil, and 

 changes are produced in the soil, physical, chemical and biochemical, 

 which influence the soil and affect its potential fertility irrespective of 

 the added plant food." 



So, the message which I bring to you today is one of optimism. I have 

 no patience with the man who is continually preaching soil exhaustion 

 and predicting the time when our soils will no longer support our 

 increasing population. The soils of Europe and Asia, which have been 

 under cultivation for centuries are still producing good crops and 

 give no evidence of any decline so long as they are properly handled. 



The maintenance of fertility, I admit, is still a big problem with us 

 but it cannot be solved on the basis of supply and demand of plant- 

 food. This has already been well demonstrated for if this were the solu- 

 tion it would have been solved long ago. But the problem is still be 

 fore us. That it will be solved I confidently believe and I look for the 

 time to come when it will be possible for* the chemist with probably 

 the assistance of the bacteriologist, the physicist and the plant physi- 

 ologist, to examine a soil sample and determine the exact cause of' in- 

 fertility and prescribe the remedy. It is going to take time, however, 



