40 UNIVERSITY OF ILLINOIS 



This is an attempt at a very brief statement of the fundamental 

 or guiding principles of Dr. Hopkins' proposition of a permanent sys- 

 tem of agriculture. There are hundreds of deviations in details, 

 most of which are yet to be worked out. Such details will vary with 

 different types of soil ; they will vary with the kind of enterprise fol- 

 lowed, whether grain farming, live-stock farming, or fruit farming; 

 they will vary with different economic situations, such, for example, 

 as affect the accessibility and the cost of different forms of fertilizing 

 materials. And so, while we may consider that the great idea of a 

 permanent system of agriculture, and the fundamental principles for 

 carrying it out, may be counted among the finished problems of this 

 Station, in reality the work on this problem is only well begun. The 

 foundation is laid, so to speak, but the great super-structure is yet to 

 be erected before Illinois agriculture as a whole shall be actually upon 

 a permanent basis. 



One of the chief questions among these unsettled problems is how 

 to maintain the nitrogen supply and this has been the subject of much 

 study. As an example along this line, a discovery of greatest practical 

 importance was made when it was found that the organism acting on 

 the roots of sweet clover also inoculates the alfalfa plant. This has 

 been followed by similar discoveries relating to the bacteria of other 

 legumes. The most recent investigations of the division of soil biology 

 are revealing very practical knowledge of the most advantageous ways 

 of handling legume crops looking toward the solution of this great 

 nitrogen problem. Numerous other investigations under way look- 

 ing toward the solution of many of these unanswered soil problems 

 might be mentioned if time permitted. 



PLANT PRODUCTION 



Turning now to that phase of our discussion that has to do with 

 plant production, let us consider next some of the work relating to 

 field crops. 



The introduction of properly adapted varieties, especially in corn, 

 has been a large factor in improved production. The attention paid 

 in recent years to the vitality of the seed must also have had a tre- 

 mendous influence in this direction. 



In corn breeding this experiment station was a pioneer. The 

 long-time selection experiments in corn to change the composition of 

 the grain have attracted world-wide attention. This investigation 

 has been continued through twenty-five generations of breeding, with 

 unbroken pedigree records, and the result has been a most remarkable 



