476 SOILS. 



vines did well in sandy land containing 35,230 pounds of alkali 

 salts, of which one half was Glauber's salt, 9,640 pounds cor- 

 bonate of soda, 7,550 pounds of common salt, and 750 pounds 

 nitrate of soda. They were badly distressed where, of a total 

 of 37,020 pounds of alkali salts, 25,620 pounds was carbonate 

 of soda ; while where the vines had died out, there was found a 

 total of 73,930 pounds, with 37,280 pounds of carbonate. The 

 European vine, then, is considerably more resistant of alkali 

 even in its worst (black) form, than barley and rye, at least 

 on sandy land; and it seems likely that the native grapevines of 

 the Pacific coast, calif oniico, and arizonica, would resist even 

 better ; a point still under experiment. 



Experience, however, has shown that vines rapidly succumb 

 when by excessive irrigation the bottom water is allowed to 

 rise, increasing the amount of alkali salts near the surface, and 

 shallowing the soil at their disposal. Such over-irrigation has 

 been a fruitful cause of injury to vineyards in the Fresno re- 

 gion, and would doubtless if practiced kill most of the vines at 

 the Tulare sub^tati >n, which are now flourishing. In such 

 cases, sometimes the formation of hardpan is followed by that 

 of a concentrated alkaline solution above it. strong enough to 

 corrode the roots themselves, and not only killing the vines, 

 but rendering the land unfit for any agricultural use whatso- 

 ever. The swamping of alkali lands, whether of the white or 

 black kind, is not only fatal to their present productiveness, 

 but. on account of the strong chemical action thus induced, 

 greatly jeopardizes their future usefulness. Many costly in- 

 vestments in orchards and vineyards have thu- been rendered 

 unproductive, or have even become a total loj 



It should be remembered in this connection that as the roots 

 of vines will, when unobstructed, go to <lcpih nf fifteen and 

 even twenty feet, a subsequent rise of the bottom water from 

 leaky irrigation ditches will drown out the ends of the deep 

 roots and thus cause the whole r< >ot ^\<-tem to become diseased, 

 inevitably resulting in unproductiveness, if not death, of the 

 vine. 



i Citrus Trees. Although the high figure of nearly 27,000 

 pounds for the tolerance of citrus trees, as given in the table, 

 seems to place them rather high on the list, such high tolerance 

 actually occurs only in very sandy soils, and when common 



