28 CALIFORNIA CITRUS CULT I' RE. 



and proceed with wisdom and energy, there is little doubt but that to 

 use the elements separately, or to mix them at home, will save much 

 money and will give good results. 



IRRIGATION. 



It has already been suggested that trees should never be allowed to 

 feel the need of water. Lack of proper irrigation is the cause of many 

 of the failures in citrus culture. Irrigation should be deep down. If 

 the grade in the orchard is slight, the run need not be so long. If 

 great, it should be longer and the stream smaller. Cross furrows made 

 with a subsoiler twelve or fourteen inches deep will often give excellent 

 results. Zigzagging the furrows among the trees, so as to get water 

 on all sides of each tree, gives the water better chance to get down to 

 the roots, and is often practiced with no little satisfaction. The great 

 desideratum is to give plenty of moisture to all of the roots all of the 

 time. It will pay admirably to dig a ditch from just under the trees to 

 the middle point between four trees at different parts of the orchard, 

 and at not too long intervals of time, to note just the condition of the 

 soil as to moisture and the way the roots are developing. Such practice 

 will often bring great surprises to the orchardist, who vainly imagines 

 that his trees are being liberally supplied with all needed moisture. 

 The King soil tester is less valuable only as it fails to show root distri- 

 bution. It costs about seven dollars, and is worth many times that 

 amount. It enables one to investigate the subsoil six feet down from 

 the surface very quickly, easily and cheaply. 



In case of a side hill, we may follow the practice so common in 

 Calabria, Italy, and in parts of Switzerland, of terracing the hill slopes, 

 though it is usually more satisfactory to contour the slope as we plant 

 our trees, and thus we may irrigate as easily as we can on a more level 

 field. The great Arlington orchard of Eiverside County, and the 

 Limoneira orchard of Ventura County are examples of where this last 

 method is practiced with entire satisfaction. As previously stated, the 

 grade of the orchard must be made perfect before trees are planted. 



In the citrus groves, no matter what age, filling the furrows and 

 cultivating the ground should be practiced just as soon after a rain 

 or irrigation as it is possible to get on to the land without injuring it. 

 Indeed, the ground should never be permitted to bake. The gauge to 

 proper tillage with a clay soil is the entire absence of lumps or clods. 

 In plowing clay soil it is the wisest plan never to leave the field until 

 all the day's plowing is thoroughly harrowed, as the possible lumps 

 are easily pulverized while they are yet moist. 



It remains to be said that clay soils are more retentive of moisture 

 than are sandy soils, and will need less and less frequent irrigations; 



