The Arizona sentinel., 1896-03-28

of che Gila and Colorado rivers have for the most part deep sedimcntary soil of brownish, gray sandy loam, resting, in most places, upon a gray clas subsoil at depth of from ten to twenty feet below the surface, The clay subsoil forms hard pan which is impcryious to water. These soils have been slowly formed by the decomposition of shales sandstoncS, mars. imestones, etc, mixed with or glnic and vegetable matter, washed down by the mighty rivers azd have been gradually deposited during she course of centuries. The ferilizing brownish mud held in the wat tIof the Colorado and Gia rivers resembles that from the Nile, and its quantity varies from o.1 to 0.5 per cent, though the water when even considerably discolor- ed by mud is good to drink resembling in this res pect the Missouri ryer water. \ chemical analysis of the sediments of the Colorado and of the Nile exhibits wonderful similarity in the constituent parts of each That Of the Colorado exhibiting a trife less potassa, most phosphoric acid and car 6onada of limestone beds through which the Colo rado pass-s In other respects the sediment of the Colorado is almost identical with that of the Nile
 It will be noticed therefore, that when this water is used for irrigation is superior to artesan waters since it is constantly supplying the land with the richestierilizing elements. The soil Of the valleys is extremely rich in dedomposed vegetable matter and uncombined carbon, readily absorbing the aerial gases such especially, oxygen, which en- tering the soil, dccomposes the organic matters so that they can be taken up ani nourish the plants which may be considered a leading featur3 in its fertility. It also readily takes up and retains moisture, while the rmness of its particles affords every facility for percoation and the activity of capillary action. In ts mechanical composition it's particles in state of very fine division, which renders it more productive than coarser soils It acquirics heat readily in the daytime, and the loss of the heat a night is yc-y gra1ual so that it re- mains always warm and i5 not subject to sudden changes Of heat and cold. Besides it's essential con stituents of water, organic or vegetable matter, sand and clay, chemical analysis shows that lime, soda, magnesia, iron, ammonia and available forms of nitrogen, phosphorc acid and potash enter into composition in the proportions best adapted to add to its fertility, though, of course as is alwaJ the casa in soil analysis its composition varies ill different localities and is not always constant.
 The soil of the uplands, or mesas, lighter end more gravelly and in some places of free, loamy, calcareous character. The mesa lands are warm and generous. They seem especially adapted for the grape olive and citrus fruits generally. Their soil contains more magnesia, lime or chalk than the bottom lands It never cracks and retains moisture admirably in summer. It is of that character which will produce wine that will keep good for fifty os a hundred years, and improve annually, not being liable to sour, exposure to the air. after one year old, to become turbid and change color n thl bottle glass.
 We can safely say that the soil Of Yuma County nowhere be surpassed containing as it does all the essential elements of richness and fertility.