THE MONTHLY BULLETIN. 231 



SOME COMMON MISCONCEPTIONS WITH RESPECT TO 

 SOILS AND SOIL FERTILITY.* 



By Chas. B. Lipman, Professor of Soil Clu'iiiislry and Bacteriology, LTniverslty of 



California. 



Mr. Chairman and GenUemen of the Fruit Growers' Convention: 

 Like the proverbial bad penny it seenis tliat I am destined to recur 

 at your gatherinu' this time with a message that may sound harsh in 

 the midst of your peaceful deliberations. In justice to myself, how- 

 ever, I nnist say that it was only after a very urgent appeal from 

 Dr. Cook that I could bring myself to assent to further imposition on 

 your good nature. Indeed, I was beginning to fear that you might 

 l)eeome possessed of a loathing for my subject (which I should con- 

 sider most unfortunate) if I did not desist from addressing you fre- 

 quently. However, I have given my Avord and must keep it, and can 

 only trust that you will find it in your hearts to forgive yet another 

 talk from me. 



Owing to the numerous papers wdiich I have read before you on 

 nearly all pliases of soils. I was at first in something of a quandary 

 as to what I should tell you this time. It soon occurred to me, how- 

 ever, that most of what I had told you in the past related to character- 

 istics of soils that do exist, and that it was higli time to declaim against 

 persistent notions of things which are not so. I shall, therefore, take 

 up several important matters in soils and soil fertility, regarding which 

 more misconception than correct information exists and trust that the 

 discussion may, from your point of view, prove to be a profitable one. 

 I shall, therefore, embark with you upon a journey of inspection into 

 some current notions regarding soils and shall consider them singly 

 pro and con. 



THE WATER AND AIR SUPPLY. 



It seems to be the common impression, among those who use water 

 on land, that water can be substituted with equally good results for 

 any of the other large classes of essentials to plant growth, of which 

 it is one. The irrigators particularly would lead one to believe, from 

 their mode of procedure in the use of water, that the other known 

 essentials to successful plant growth, namely, air, heat, light and plant 

 food, were of no significance. IMoreover, there is much disposition to act 

 on the somewhat ridiculous idea that "if a little water is good, more is 

 better. ' ' 



From things that I have discussed with you in past meetings of 

 this organization, you must be fully aware that a soil is so constituted 

 that the soil material proper occupies on the average only half of its 

 volume; thus half of an acre foot of one whole acre foot is open space. 

 In that open space both air and water — two of the five big essentials 

 named above — must find harmonious lodgment. Careful research, 

 moreover, makes it appear cpiite certain that such harmonious propor- 

 tions of air and water, under average conditions, would be equivalent 

 to the use of half the open space by w^ater and half of it by air. But 



♦Address before State Fruit Growers' Convention, Los Angeles, Cal., Novem- 

 ber 12, 1914. 



