28° CALIFORNIA CITRUS CULTURE. 
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. Zigzageing 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 Riverside 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 elods. 
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 ; 
