280 CITRUS FRUITS AND THEIR CULTURE. 



roots that grow from the hundreds of laterals branching 

 from the large main roots. 



"If a plow is run to a depth of one foot, in three fur- 

 rows, between the rows, and water percolates slowly for 

 a long time through these furrows, no need can arise for 

 a sub-soiler. 'Irrigation hard-pan' within reach of the 

 plow simply shows, as has been said, that too shallow 

 and too uniform cultivation has been practiced. In that 

 case the entire surface should be thoroughly broken up, 

 and irrigation in deep furrows after this will restore the 

 proper conditions. 



"Experience also shows that when the water is slowly 

 run in deep furrows for a long time and the greater part 

 of the surface is kept dry and is deeply cultivated, better 

 results are obtained than when the basin or block method 

 or even the shallow-furrow plan is used, even though they 

 are followed by deep cultivation. When the water is 

 applied below the first foot of soil, and the soil above is 

 kept comparatively dry, there is nothing to attract the 

 roots to the surface; and when the water is thus applied, 

 a team can be driven along the dry strips of land between 

 the furrows, and with a harrow or other appliance the 

 dry soil can be dragged into the wet furrows, to lessen 

 the evaporation, immediately after the irrigation water 

 is turned oft'. By any other system it is absolutely nec- 

 essary to wait at least twelve hours, and sometimes much 

 longer, before a team can be driven over the ground. 

 Then, too, when a soil irrigated by these more wasteful 

 methods has been cultivated, it is still moist near the top, 

 and is soon filled with a mass of new roots so close to 

 the surface that they must be destroyed. 



"Water applied to the soil sinks and spreads. Some 

 of it is being taken up by the still dry soil underneath 



