124 



studied by all those owning or interested in lands in tropical cen- 

 ters, as by their doing so many areas at present neglected and 

 further deteriorating would, we believe, not only be made revenue 

 yielders, but would also tend to become more fertile. "Nearly 

 six-tenths of the earth's land surface,'' Dr. Widtsoe tells us, "re- 

 ceive an annual rainfall of less than 20 in., and can be reclaimed 

 for agricultural purposes only by irrigation and dry farming. A 

 perfected world-system of irrigation will convert about one-tenth 

 of this vast area into an incomparably fruitful garden, leaving 

 about one-half of the earth's land surface to be reclaimed, if at 

 all, by the methods of dry farming." Unfortunately we have no 

 room to properly review the book, but a glance at the index is 

 bound to send the most indifferent cultivator, if he is in any wise 

 worthy of the name, foraging through the book to see what it has 

 to say. Take the question of root systems, to which Chapter Vl 

 is devoted ; here we find discussed such matters as functions, kinds, 

 extent, and also depth of root penetration. The present status 

 of dry farming is described in Chapter XVIII throughout the 

 United States, and then in Mexico, Brazil, Australia, Africa, and 

 the East. So much for places; now for products; and -the Times 

 of Ceylon again. This paper tells us that "The growing demand 

 for land for the cultivation of the more important commercial 

 products and the opening, in recent years, of extensive plantations 

 has resulted in a very large area of what is considered suitable 

 land being absorbed ; the possibility of cultivation in the dry 

 zone (i. e., of Ceylon) has therefore been attracting attention for 

 some time ; this being so. the point to be considered is what prod- 

 ucts can be profitably cultivated in this arid zone.'' The follow- 

 ing crops are discussed and recommended : Ceara rubber, to- 

 bacco, cassava, chillies, ground-nuts, as well as the raising of 

 stock and the fodder to feed them. Dr. Fernando's paper also 

 discusses the same ideas. From all we can learn from these and 

 other reports on the utilization of tropical areas with a low rain- 

 fall, we feel certain that a far larger number of land-owners 

 should make careful studies of the advantages oft'ered by the 

 modern system of dry farming. 



Dr. Widtsoe's remarks on pp. 92, 93 are worth noting by those 

 who believe, as we do, in breaking up the top soil between cacao, 

 rubber, and other trees in the tropics, to conserve tiic moisture 

 during times of drought, by breaking the ca])illary attraction that 

 draws the subsoil water to the surface when it evaporates and is 

 lost, but fear to do so, lest by damaging the surface roots they do 

 more harm than good. "A great deal," he tells us, "has been said 

 and written about the danger of dcei) cultivation, because it tends 

 U) injure the roots that feed near the surface. True, deep culti- 

 vation, csj)ccially when ])er formed near the plant or tree, destroys 

 the surface-feeding roots, but this only tends to compel the (lee])cr 

 lying roots to make better use of the subsoil. When the subsoil 

 is fertile, and furnishes a sufficient amount of water, destroying 



