THE ORANGE IN CALIFORNIA FERTILIZATION. 137 



of our failure to sufficiently aerate the soil by proper and 

 frequent cultivation. The air, I believe, is an essential factor 

 in carrying on the process of nitrification. A circulation of air 

 through the soil will unquestionably increase the available 

 supply of nitrogenous food. 



I know little of chemistry, but I observe that soils kept open 

 and thoroughly aerated produce great growth, even without 

 the application of fertilizers of any kind; whereas, soils com- 

 pacted, however rich in plant-food, will not compare in results. 

 I thus philosophize because I believe much plant-food will 

 never be utilized until the soil is properly aerated. Cultivation 

 is therefore an important factor in proper fertilization of soil. 



How to Apply. Fertilizers are variously applied by orchard- 

 ists. One grower, and he has a fine, well-kept orchard I notice, 

 scatters barnyard or sheep manure immediately around the 

 trunks of the trees, and extending out five or six feet. Generally, 

 however, fertilizers are scattered broadcast between trees and 

 plowed under; some, however, drill them in. The latter, for 

 commercial goods or ground sheep manure, is the best method 

 in my opinion. I observe that the grove first referred to is 

 vigorous in growing, but this year has a light crop. 



However, the advocates of these different methods generally 

 point to good crops as the result of their plans. One thing is 

 certain, it either makes little or no difference with us what is 

 used, or how applied, or else the fertilizers are so all-powerful 

 that it is only necessary to have them come in contact with 

 the soil to have it respond. 



Some of our people have experimented with green crops for 

 fertilizing, but have nothing satisfactory to report. Perhaps if 

 they had used some of the leguminous plants recently secured 

 from Europe, and so highly recommended by Professor Hilgard 

 and others, results might have been quite different. 



More Investigation Desirable. I want to commend this 

 subject to the careful investigation of the more observing and 

 scientific of our growers, so that the work of fertilizing our 

 citrus orchards may be reduced to a science so plain, simple, 

 and practical that any of us may comprehend it, and that the 

 results will be such that an all-assuring faith in its principles 

 may prevail. I am pleased to note that the Agricultural 

 Department of our State University, as well as those interested 



