Food for Plants. 



129 



How It Was Done at Corona, California. 



The rows were trenched eight inches deep, just out- 

 side the drip of the trees and the fertilizers spread in the 

 trench opposite the whole width of each tree. This was 

 done on two sides of each row in the same direction, then 

 covered by the plow. This, the only plowing, was done on 

 March 7, 1918. The application of fertilizers in trenches 

 is found to give the best results in the orange groves of 

 this section. 



Six after-cultivations to a depth of five or six inches 

 were given. These six cultivations were made during the 



Results at Corona. 



32.2 Boxes Oranges. 

 Yield of 1/10 acre 

 fertilized with Acid 

 Phosphate alone. 



41.1 Boxes Oranges. 

 Yield of 1/10 acre 

 fertilized with Ni- 

 trate of Soda and 

 Acid Phosphate. 



forepart of each of the months of March, April, May, 

 June, July and August. The March cultivation consisted 

 of a thorough disking. The other five cultivations were 

 made with the ordinary orchard cultivator. 



The above trench fertilizing was done parallel with 

 irrigation furrows up one side and down the other, noth- 



