The Arizona sentinel., 1896-02-08

of the Cila and Colorado rivers have foI the most part deep sedmcntary soil of brownish, gray sanfy loam, resting, in most places, upon gray clay Subsoil at depth of from Sen to twenty feet below the surface, The clay subsoii forms Q hard pan which is impervous to water. These soils have been slowly formed by the decomposition of shales, sandstones, marls. mestones, etc, mixed with or glnic and vegetable matter, washed down by the mighty rivers and have been gradually deposited during the course of centuries. The fertilzing brovnish mud held in the wat tlOf the Colorado and Gila rivers resembles that from the Nile, and its quantity varies from 0.l to O.5 per cent, though the water when even considerably discolor- ed by mud is good to drink resembling in this res pect the Missouri river water A chemical analysis of the sediments of the Colorado and of the Nile exhibits a wonderful similarity in the constituent parts of each. That of the Colorado exhibiting a triae less potassa, most phosphoric acid and car bonade of limestone beds through which the Colo rado passos 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 it is superior to artesian waters since it is constantly supplying the land with tine richestfertilzing elements. The soil of the valleys
 
 and uncombined carbon, readily absorbing the aerial gases, such especially oxygen, which en- tering the soi dccomposes the organic matters so that they can be taken up and nourish the plants which may De considered leading featur2 in its fertility. It also readily takes up and retains moisture while the irmness of it's particles affords every facility for pefcolatiOn and the activity of capillary action. IR ts mechanical composition it's particles are in state of very fine division, which renders it more productive than coarser soils It acquiries heat readily in the daytime, and the loss of the heat at night is very gradual, so that it re mains always warm and is not subject to sudden changes of heat and cold Besides its essential con stituents of water, organic vegetable matter sand and clay, a e. :ual analysis shows that lime sodz magnesa, iron ammonia and available forms of nitrogen, phosphoric acid and potash enter into composition in the proportions best adapted tc add to it's fertility though of course, as is alwal the case in soil analysis it's composition varies r different localities and is not always constant.
 The soil of the uplands, OF mesas, lighter and 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 ol a hundred years, and improve annually, not being liable to souri, exposure to the air, after one year old, to become turbid and change color in the bottle or 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.