PLANT ECOLOGY AND THE NEW SOIL FERTILITY 



Chas. B. Lipman 



University of California 



The writer of this brief statement begs the indulgence of his 

 auditors and requests consideration by them of his suggestion for 

 employing the methods of modern soils science in the study of 

 problems of plant ecology. It has been demonstrated beyond 

 cavil that no royal road is available which leads to the solution 

 of the problems of plant nutrition under field conditions and to 

 that of a control of all the factors necessary to proper plant growth 

 which are controllable. Moreover, empiricism has proved itself 

 woefully inadequate to cope with the problem In the face of one 

 of the most complex situations which confront the investigator 

 in any branch of scientific activity. It appears to be high time 

 therefore that methods be adopted in plant ecological investiga- 

 tions which are based on sound principles obtained from investi- 

 gations in the pure sciences. The methods of attack employed 

 by the modern soils scientist it seems to me are admirably adapted 

 to such study since they have resulted from an attempt to escape, 

 in soils science, from the empirical and haphazard, and are now 

 forging ahead systematically with one factor in view at a time, 

 in the development of a new and more justifiable view-point in 

 soil and plant studies. 



Until now the criteria employed in the study of the so-called 

 plant associations have been few and their raison d'etre ofttimes a 

 questionable one. From the standpoint of the soil, moreover, 

 scarcely any criteria have been developed which might serve us 

 in judging of the conditions instrumental in causing the establish- 

 ment of flora through secular selection. To be sure, some atten- 

 tion has been paid to the reaction of the soil as affecting the nature 

 of the flora and studies have been made which bear on the part 

 played by the plants with nitrogen fixing powers in establishing 

 through encouragement or competition certain recognized plant 

 associations. Unfortunately, however, the question of a soil's 



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