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. 1 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. 



1 This plant growth in the basins can, of course, be used to supplement the mulching 

 material. 



