112 STATE BOARD OF HORTICULTURE. 



depth, covers the entire area between trees, even at an early 

 age of the orchard. This is crowded with roots, from the 

 minutest fibers to the largest branches of the leaders found in 

 running the plow fourteen inches deep in an eight-year-old 

 orchard. Many roots were cut from three eighths of an inch 

 down. To get the full force of this, we must remember that a 

 root even a quarter of an inch thick may extend for yards 

 from the point where severed, with its thousands of branchlets 

 bearing the minute hair appendages that take up the tree's 

 nutriment. 



This makes pretty severe root pruning. How great the 

 injury this will occasion, considering the great mass of roots 

 from which such trees gain their support, and how quick the 

 recuperation after injury, I can yet form no opinion of any 

 value. But certainly there will be a lot of root growth to be 

 made up, and in the meantime a lot of little mouths lacking to 

 take up the food of the tree. But there may be cases where 

 the advantage to remaining roots may more than make up for 

 this loss. In any event, it would be much better if not only 

 this root pruning, but also all the expense connected with the 

 deep plowing, were not necessary. And this brings me to the 

 second part of my subject. 



Can the necessity for it be avoided by guarding against the 

 formation of this obstructing layer while orchards are young? 

 I am quite of the opinion that it may. But my experience has 

 been with orchards under ten years old, and I have learned 

 that we are frequently obliged to revise opinions very confi- 

 dently held, as our actual experience extends under new con- 

 ditions, and this opinion may be quite wrong. If the hard 

 layer is occasioned by repeated drying-out after irrigation, a 

 portion of that stratum should be thoroughly broken up once 

 or twice a year before becoming hard, while the balance of it, 

 I think, can be kept from hardening by careful irrigation. This 

 opinion is based on a good many years' experience in all soils 

 from the sandy loam to stiff adobe, without any of this trouble- 

 some layer; yet you will allow me to refer to this experience in 

 illustrating not in any dogmatic spirit, for every year more 

 and more I find that different men will accomplish the same 

 desired results best, by quite different means. Once a year we 

 thoroughly break up the surface with a walking plow, as deep as 

 we can without permanent injury to the root system, say from 



