Agricultural Development 

 following losses in twenty-one days, with and with- 

 out a soil-raulch by tillage: No mulch, 14 1/3 

 per cent of water applied; 3-inch mulch, 4 per 

 cent; 6-inch mulch, 2 per cent; and 9-inch mulch, 

 1 per cent. 



Dr. Fortier concludes: "From the foregoing it 

 is evident that western orchardists can prevent the 

 greater part of the evaporation losses by cultivating 

 orchards to a depth of at least six inches as soon 

 as practicable after each irrigation." 



These results give quite sufficient reason to in- 

 sist upon the mastery of tillage and irrigation in 

 moisture conservation. Besides there is, of course, 

 the efficacy of tillage in giving the plant soil aera- 

 tion and other conditions essential to vigorous and 

 free root action — including restoration of fertility 

 by action of soil bacteria which in the arid region 

 has been demonstrated by Dr. G. B. Lipman of the 

 University of California, to be in operation "at 

 much greater depth in soils of the arid than in 

 soils of the humid region.* Dr. R. H. Lough- 

 ridge, of the same institution, demonstrated "the 

 distribution of humus-nitrogen through twelve feet, 

 thus giving the soil in the arid region a higher 

 total of humus-nitrogen than is found in humid 

 soils." 



The distinctive characters of the soils, and the 

 relations thereof to irrigation and tillage, are of 

 determinative importance in the development of 

 the arid region, as may be readily inferred even 

 from the foregoing fragmentary discussion. 



Fifth: the Quality of Manhood. — Of course 

 the ruling factor in the development of the far 

 west has been the quality of manhood involved in 

 the achievement, but this need only be suggested 

 in this connection. The earliest of the pioneers 

 were chiefly natives of the middle west, where 

 they had been born to heroism, adventure, and un- 

 precedented achievement. They were strong in 

 initiative, resourceful, venturesome, full of the 

 American spirit and cherishing American ideals 

 of equality of manhood and of opportunity. Those 

 who followed the first run of pioneers were also 

 possessed of an exceptional average of spirit and 

 capacity — the very difficulties of the approach to 

 the arid region set up barriers of exclusion against 

 both physical and spiritual weakness. Though the 

 venture for gold in California brought a motley 

 crew, the weaklings were soon excluded by the 



* University of California Publications in Agricultural 

 Science, Vol. 1, No. 1, pp. 17, 20; Idem, Vol. 1, No. 8, p. 179 

 et seq. 



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