INTRODUCTION 11 



as from the physical group. Accordingly, depending on whether 

 we are interested in the problems from a botanical or an economic 

 aspect we are inclined to minimize the preponderating influence 

 of the economic or the physical factors. 



Crop ecology may be viewed from two distinct angles. It is a 

 natural center from which the various phases of the scientific sides 

 of agriculture radiate. This is because the basis of crop ecology 

 is in plant physiology. An increase in the yield of crops is the re- 

 sult of changes in controlled conditions. These may be in the soil 

 or in the plant, and if in the latter the favorable variations are made 

 permanent by selection and plant breeding. If in the foraier, we 

 have the agronomists and plant physiologists to experiment for 

 certain definite ends and to explain why we arrive at certain results. 



In the second place, crop ecology should be regarded as an ex- 

 periment in organization. It tries to show how the various aspects 

 of plant life, the adaptations, the growth habits, the disease resist- 

 ance must be unified and brought to a focus for further progress in 

 agriculture. Success in the future rests, not in allowing the pathol- 

 ogist and the geneticist and the agronomist to jog along independ- 

 ently, but in combining their forces. And for the business end of 

 fanning the economist must also be invoked so that a complete chain 

 stretches from the producer to the consumer. At present our agri- 

 culture is somewhat like a partly organized machine. All the parts 

 have been assembled and can be made to work separately, but for 

 the machine to be in smooth-running order, the operation of all 

 of these parts must be synchronized. Furthermore, increasing the 

 speed of one part of the machine, is likely to result in nothing more 

 than a few broken cogs and stoppage of the output, unless this 

 speeding can be compensated in the different parts. In a cotton 

 yam factory, for instance, unless all the wheels upon which the 

 spools turn revolve at the same rate the threads are not held at the 

 same tension and develop weak spots or the skein may even break 

 and have to be started over. The moral is that our agricultural 

 threads must all spin together at the tension necessary to make a 

 smooth, straight cord, capable of withstanding the strain of our 

 ever increasing population. Strange as it may seem after so many 

 years of our experimental stations and colleges of agriculture, the 

 living plant has not yet been seriously considered the logical start- 

 ing place about which agricultural instruction is to be grouped. 



Whether or not genetic ideas may be applied to the classifica- 

 tion of soils remains to be proved by experiment. It seems reason- 



