114 STATE BOAKD OF HORTICULTURE. 



grade and open at bottom and top so that air passes through it, 

 there will never be trouble from orange roots. Valves, once 

 thought necessary, are not now used. The high cost of the 

 present sub-irrigation systems places them beyond the reach 

 of most orange-growers. 



SUBSOIL PLOW.* 



Can the necessity for the use of a subsoil plow be avoided by 

 guarding against the formation of hardpan while orchards are 

 young? I am quite of the opinion that it may. But my expe- 

 rience has been with orchards under ten years old, and I have 

 learned that we are frequently obliged to revise opinions very 

 confidently held, as our actual experience extends under new 

 conditions, 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 hy careful irrigation. This 

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

 from 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 w'ithout permanent injury to the root-system, say from 

 six to nine inches. In our earlier planted orchard, where we 

 did not commence with especially deep plowing, we have trouble 

 with the roots even at six inches. In our later plantings, on 

 deep plowing, repeated each season, we can keep a depth of 

 seven to nine inches easily. With this annual plowing we 

 have no trouble in getting the water into the ground during 

 the irrigating season. We aim to make the irrigation most 

 thorough every time. As aids to this, I want to mention three 

 things that we have found of great importance : 



First— We make our irrigating furrows as nearly the depth 

 of the annual plowing as possible, thus putting the water 

 nearest where needed, greatly reducing the surface saturation 

 where so much water is wasted, and facilitating the early 

 covering of the furrows after irrigation. 



*Essay by J. H. Reeil, of Riversi'le, read at the Highgrove and Pasadena 

 Farmers' Institute, January, 1900. 



