50 



rooting of all plants in arid climates ; whereby not only a much, larger 

 bulk of moist soil is at their command, but the root* are withdrawn 

 from the injurious effects of the hot, dry surface and air. 



This deeper range of the roots is not the result of foresight on the 

 part of the plant. It could not occur on Eastern soils, because of the 

 intervention, in the great majority of cases, of difficultly penetrable sub- 

 soils ; from which, moreover, plants could draw but little nourishment 

 on account of their " rawness." In the arid region, as a rule, sub- 

 soils in the Eastern sense do not exist ; the soil mass is practically the 

 same for several feet, and in the prevalent soils is very readily pene- 

 trable to great depths. This, summarily speaking, is due to the slight 

 formation of clay, and the rarity of heavy rains, in the arid region. 

 And this easy penetrability of the soil implies, moreover, that being 

 well aerated, the depths of the soil are not " raw," as in the East ; and 

 therefore that the "sub-soil," such as it is, may fearlessly be turned 

 up as deeply as the farmer is willing to go with the plough, without 

 danger of injuring the next season's crop, in all lands that are well 

 drained ; as, by reason of their depth and perviousness, is the case with 

 most California soils. 



We know the deep penetration of a peach root developing in a nor- 

 mally deep, well aerated " bench'* soil, in a manner quite impossible to 

 the same root when growing in land underlaid, as are most Eastern 

 States ones, by a subsoil which either is too dense or too wet to be 

 penetrated and utilized by the tree. 



A root system of a typical Eastern tree root will stand in absolute 

 need of frequent rains or irrigation to sustain its vitality, but a Cali- 

 fornia tree may brave prolonged drought with impunity, being inde- 

 pendent of surface conditions, and able to perform all its functions out 

 of reach of stress from lack of moisture.* It is equally clear that it 

 is to the farmers interest to favour, to the utmost, this deep pene- 

 tration of the roots, both in the preparation and tillage of the ground, 

 and in the use of irrigation water. For if the latter is used too fre- 

 quently or too abundantly, the salutary habit of |deep rooting will be 

 abandoned by the plant, and it will, as in the East, be dependent upon 

 frequent rain or irrigation ; and also, owing to the small bulk of soil 

 upon which it can draw for its nourishment, upon frequent and abun- 

 dant fertilization. 



Eastern immigrants as well as a large proportion of California 

 farmers do not realize the privilege they possess of having a triple and 

 quadruple acreage of arable soil under their feet, over and above the 

 area for which their deeds call ; and they tenaciously continue to 

 adhere to precautions and practices which, however salutary and 

 necessary in the region of summer rains, do not apply to this climate. 

 The shallow ploughing so persistently practised results in the formation 

 of a " ploughsole" that plays the part of the Eastern subsoil in prevent- 

 ing root penetration ; limiting their range for moisture and plant food, 

 and thus naturally causing crops to succumb to a slight stress of season 

 which ought to have passed without injury, had the natural conditions 

 been taken into proper consideration. 



* The moisture determination under this tree gave/[to the depth of eight feet, 

 an aggregate amount of water of 1,058 tons per acre. 



