THE DIVERSIFIED FARM. 



SUBSOIL PLOW. 



(Paper read at the Highgrove and Pasa- 

 dena Farmer's Institutes \>y J. H. Reed). 



Citrus fruit growers have made a great 

 advance in the science and practice of or- 

 chard cultivation during the last decade. 

 How great, I do not think we appreciate 

 till we carefully review the cruder methods 

 and more or less mistaken notions prevail- 

 ing ten years ago. But in spite of the 

 much we have learned, new problems arise 

 continually, which require new study. 

 Just now one that is attracting consider- 

 able attention is the difficulty found, es- 

 pecially in some of our older orchards, of 

 getting the soil to take irrigating water as 

 readily as is desirable. The cause is found 

 in a hard stratum of earth just under the 

 cultivated portion, varying in thickness 

 from a few inches to a foot or more, which 

 is sometimes almost impervious to water. 

 The result is, difficulty in keeping the 

 root stratum underneath sufficiently moist. 

 This hard layer is doubtless caused by 

 frequent wetting and drying out. Not be- 

 ing disturbed, it becomes harder after each 

 irrigation, the same as the surface would 

 if not carefully stirred, only to a lesser de- 

 gree. The cultivator shovels constantly 

 running over this layer also has a firming 

 effect on it. The first question is, how 

 best to get rid of this objectionable stra- 

 tum of earth. In the East, we remember, 

 that it is very desirable to break up the 

 sub-soil without bringing it to the surface. 

 This their modern subsoil plow does ef- 

 fectually. 



The plow is now being introduced here 

 for the purpose of breaking up this hard 

 layer. And those who have tried it, so 

 far as I can ascertain, seems favorably im- 

 pressed with the results. The plow is 



usually run in the center of the spaces be- 

 tween trees once each way from 12 to 16 

 inches deep. It does not disturb the sur- 

 face further than the mark left by the thin 

 standard, but lifts the subsoil sufficiently 

 to break it up to the width of 12 to 20 in- 

 ches on each side. The draft, where the 

 ground has become hard, is necessarily 

 heavy even with the small shoe and thin 

 standard, requiring from six to eight good 

 horses. These narrow broken spaces take 

 in the water very readily. How long it 

 will take it to work out under the unbrok- 

 en squares till the entire root bed is wet- 

 ted, and how permanent may be the re- 

 sults are questions yet to be determined. 

 If the same general trentment of the or- 

 chard is followed, the hard layer will 

 doubtless gradually reform, and this 

 special process need to be re- 

 peated. 



An important consideration is the effect 

 of the disturbance of the roots necessarily 

 made by this deep plow. I have not been 

 able to see its workings in an old orchard. 

 In orchards seven to ten years old the 

 leaders at that distance from the trees 

 have not become large. But the root stra- 

 tum commencing immediately below the 

 cultivated portion, to an indefinite depth, 

 covers the entire area, between trees even 

 at an early age of the orchard. This is 

 crowded full of 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- 



