June, 1909.] 



561 



Live Stock. 



With these exceptions— if it be added 

 that the author has an extremely old- 

 fashioned' and obsolete way of spelling 

 Indian place-names— we have nothing 

 but commendation for the volume before 

 us, the species being clearly and care- 

 fully described, with full and well- 

 written notices of their distribution and 

 habits. As Mr. Baker observes, the 

 collection and collation of a vast amount 



of scattered information concerning the 

 Indian Anatidse lenders it from the 

 first possible to know the extent of our 

 information on the subject, and to 

 realise what gaps require filling up. 

 The book should be in the library of 

 every Indian sportsman, by whom it 

 should be taken into camp in each 

 winter's sporting trip. 



R. L. 



SCIENTIFIC AGRICULTURE. 



THE CONSERVATION OP SOIL 

 MOISTURE AND ECONOMY IN 

 THE USE OF IRRIGATION 

 WATER. 



By E. W, Hilgard and R. H. 



LOUGHBRIDGE. 



(From the University of California 

 A gricultural Experiment Station 

 Bulletin 121.) 



(Continued from p. 4S6,) 



Basin Irrigation.— It will be noticed 

 that this principle is practically the 

 same as that of the basin irrigation of 

 orchards, which was originally largely 

 practised in California, but has now 

 been mostly abandoned for furrow irri- 

 gation. The latter has been almost 

 universally adopted, partly because it 

 requires a great deal less hand-labour, 

 partly under the impression that the 

 whole of the soil of the orchard is thus 

 most thoroughly utilized ; partly also 

 because of the injurious effect upon 

 trees produced at times by basin irri- 

 gation. 



The explanation of such injurious 

 effects is, essentially, that cold irrigation 

 water depresses too much the temper- 

 ature of the earth immediately around 

 the roots, and thus hinders active vege- 

 tation to an injurious extent, sometimes 

 so as to bring about the dropping of the 

 fruit. This, of course, is a very serious 

 objection, to obviate which it might be 

 necessary to reservoir the water so as to 

 allow it to warm before being applied to 

 the trees. In furrow irrigation the 

 amount of soil soaked with the water 

 is so great that the latter is soon effec- 

 tually warmed up, besides not coming 

 in contact too intimately with the main 

 roots of the tree, along which the water 

 soaks very readily when applied to the 

 trunk, thus affecting their temperature 

 much more directly. It is for the f ruit- 

 grower to determine which consider- 

 ation should prevail in a given case. If 

 71 



the water-supply be scant and warm, 

 the most effectual use that can be made 

 of it is to apply it immediately around 

 the trunk of the tree, in a circular 

 trench dug for the purpose. When, on 

 the contrary, irrigation water is abun- 

 dant and its temperature low, it will be 

 preferable to practise furrow irrigation, 

 or possibly even flooding. As to the 

 more complete use of the soil under the 

 latter two methods, it must be remem- 

 bered that while tnis is the case in a 

 horizontal direction, yet unless irriga- 

 tion is practised rather sparingly under 

 the furrow system, it may easily happen 

 that the gain made horizontally is more 

 than offset by a corresponding loss in 

 the vertical penetration of the root-sys- 

 tem. This is amply apparent in some of 

 the irrigated orange groves of Southern 

 California, where the fine roots of 

 the trees fill the surface soil as do the 

 roots of maize in a corn field of the 

 Mississippi States ; so that the plough can 

 hardly be run without turning them up 

 and under. In these same orchards it 

 will be observed, in digging down, that 

 at a depth of a few feet the soil is too 

 water-soaked to permit of the proper 

 exercise of the root functions, and that 

 the roots existing there are either in- 

 active or diseased. That in such cases 

 abundant irrigation and abundant ferti- 

 lization alone can maintain an orchard 

 in bearing condition is a matter of 

 course ; and there can be no question 

 that a great deal of the constant cry for 

 the fertilization of orchards in the 

 irrigated sections is due quite as much 

 to the shallowness of rooting induced by 

 over irrigation, as to any really neces- 

 sary exhaustion of the land. When the 

 roots are induced to come to and remain 

 at the surface, within a surface layer 

 of eighteen to twenty inches, it natur- 

 ally becomes necessary to feed these 

 roots abundantly, both with moisture 

 and with plant food. This has natur- 

 ally led to an over-estimate of the 

 requirements of the trees in both 

 respects. Had deep rooting been en- 

 couraged at first, instead of over-stimu- 

 lating the growth by surface fertilize- 



