138 THE MONTHLY BULLETIN. 



Citrus fruits, especially oranges, are grown successfully throughout 

 the entire length of the belt. They thrive on a wide range of soils, 

 but the best results appear to be when the trees are planted on loams 

 and clay loam adobes below the 1,200 foot contour. :\Iany and diverse 

 are the "methods of handling this highly specialized crop and the range 

 of soils utilized for the industry is wide. With the longevity of orange 

 trees and the small amount of study given to their requirements, it 

 is difficult to make positive statements at the present time as to the 

 soils best suited to this industry. This item awaits its solution in the 

 future, and the root stock used will undoubtedly be found to be a 

 very important factor in determining the kind of soil on which any 

 variety will thrive best. 



The general experience north of the Tehachapi is that it requires 

 from $700 to $800 to bring a grove into bearing, including the cost 

 of land and water and if all the operations are done by hired labor. 

 The average net returns are about $100 per acre and they are increased 

 or diminished noticeably by the amount of power required to handle 

 the soil and by the knowledge of the grower in developing a soil con- 

 dition which meets the greatest needs of the trees without waste. 



In the lower foothills the adobe soils used most extensively for the 

 culture of citrus fruits contain areas conunonly known as dry earth 

 bogs. Such areas consist of puffed or heaved, well granulated masses 

 of soil, into which a man or animal sinks deeply when walking on it. 

 The soils in such areas are underlaid by a stratum or large lens-shaped 

 area of marly material very high in lime. Such areas, and other 

 soils which have unusually rich marly seams through them at depths 

 of four feet or less, should be avoided for the growing of citrus fruits. 

 Trees in such places thrive until the roots enter the marly layers and 

 then the leaves turn yellow and the trees decline and die prematurely. 

 The location and soil type have an important bearing on the duty 

 of water, and this is an important item in the citrus belt. The same 

 types located on slopes of good gradient require about one miner's inch 

 of water to three or four acres and on more gentle slopes and nearly 

 level areas the duty is one miner's inch to two or three acres. 



The adobe soils are high in humus, but with citrus growing the use 

 of cover crops plowed down as often as possible greatly aids in improv- 

 ing the physical condition of these heaw types. Commercial fertilizers 

 on such soils appear to be of little value and in scarcely any places 

 visited was it found that the increase in fruit was commensurate with 

 the added expense of mineral fertilizers. In fact, the use of commercial 

 fertilizer in this entire belt appears to be much like the use of patent 

 medicine: "good in an occasional instance and a useless expense in a 

 ma.jority of cases." 



The lighter types of soil, such as light loams and sandy loams, seem 

 to stimulate early and very heavy bearing for the citrus fruits, but it is 

 doubtful if the "length of life of the orange tree will be as great in 

 such soils as on the heavy loams and light adobe soils. 



The soils in the foothills belt are generally fertile and their greatest 

 requirement appears to be organic matter. They are all well supplied 

 with mineral plant food, but the heavier types rank first and are the 

 most durable soils. With good tillage, organic matter, and care, trees 

 have been kept vigorous and productive for 20 years or more without 



