No. 4.] SOIL FERTlLIXr. 121 



PEESENT DEFINITIONS OF SOIL FERTILITY. 



BY UK. W. H. JORDAN, GENEVA, N. Y 



Soil fertility is a subject of vast economic importance. 

 It is a trite saying, now so obviously true as to need no argu- 

 ment, that soil resources are the fundamental resources of 

 our material prosperity. Our fruit, stock and dairy inter- 

 ests are the agricultural superstructure of which the pro- 

 ducing power of the soil is the foundation. Because these 

 things are true, dire prophecies of disaster have been uttered 

 concerning that nation the productivity of whose fields should 

 have become weakened. Doubtless you all recall the jeremiad 

 of Professor Crookes, in his address in 1898 as president of 

 the British Association, in which he prophesied that in 1931 

 the wheat suppl}^ of the world would fall below the real need 

 of the human family, because of the lack of available soil 

 nitrogen. While Professor Crookes' conclusions seemed to 

 many to be based upon insufficient and incorrect premises, 

 these utterances show the solicitude Avith which thoughtful 

 men regard problems of soil fertility in their relation to 

 human welfare. 



Perhaps you wonder why I have selected this theme for 

 to-day. ^ly reason is that, while the subject is certainl}' old, 

 we seem to be constantly viewing it from ncAV and interest- 

 ing points of view. I am quite sure that no well-informed 

 man would now discuss soil fertility from the same stand- 

 point from wdiich he viewed it fifty, twenty-five or even ten 

 years ago. It may be well to say, as a cheering antieii)ation 

 of what is to follow, that it is not so easy to be a prophet of 

 evil now as it was at one time. He who would now place 

 the future subsistence of the race on so precarious and 

 gloomy a basis as has sometimes been presented to us, might 



