MULCHED-BASIN SYSTEM OF IRRIGATED CITRUS CULTURE. 25 
The maintenance of the dikes is a small item of expense, and with 
a furrow along the side of the basins for irrigating each basin sepa- 
rately there should be no upkeep expense for two years at least, and 
probably the dikes will last longer. It is necessary, however, to use 
only a small stream of water in filling the basin, especially on land 
with a steep slope, as otherwise the silt and fine sand brought into the 
basin will in time fill it, necessitating future excavations, with the 
loss of a part of the rich soil formed. 
The cost of the application of water will probably be greater with 
the basin system, as it will be necessary to keep a night irrigator on 
duty during irrigation. On the other hand, there is a marked saving 
in the quantity of water used and a marked saving through the 
elimination of teamwork of all kinds in the orchard except for haul- 
ing fruit and replenishing the mulching material. The breaking of 
heavy fruit-bearing branches during cultivation and the injury of 
fruit from contact with harness or harrow are also avoided. 
LIMITATIONS OF THE MULCHED-BASIN SYSTEM. 
The mulched basin is not the solution of all the difficulties of citrus 
culture. It will probably be found less advantageous on sandy or 
sandy loam soils than on loam or clay-loam soils. It is not suitable 
for heavy gumbo soils. Some hand labor (hoeing or mowing) will 
be required to keep the weed growth in the basins under control and 
to prevent undue loss of moisture from this source... The organic 
mulch in the basins will also harbor some gophers, although experi- 
ence so far indicates that the frequent flooding of the basins dis- 
courages them from seeking refuge under the mulch. The proximity 
of the roots to the surface necessitates the maintenance of an effective 
organic mulch in the basins for the best results. The cost of suitable 
mulching material will very greatly depend on the location of the 
groves and in some cases may seem prohibitive. In this connection 
it must be remembered that the humus content of some citrus groves 
has been reduced to such a degree that its restoration by some means 
appears imperative. The efficiency from the nutrition standpoint of 
the organic material applied to the surface in comparison with the 
same material plowed under remains to be determined. 
The marked response of citrus trees under the mulched-basin sys- 
tem in the experimental tracts justifies its serious consideration by 
citrus growers. Its final position in the industry can be determined 
only after it has been thoroughly tested in comparison with other 
systems in commercial practice. 
1This plant growth in the basins can, of course, be used to supplement the mulching 
material. 
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