The Arizona sentinel., 1895-02-23

O the Gila and Colorado rivers have for the most part deep sedimentary soil of browniSh, gray sandy losm, resting, in most places, upon gray clay subsol at a depth of from ten to twenty feet below the surface, The clay subsoil forms hard pan which is imperyious to water. These soils have
 been slowly formed by the decomposition of shales sandstones, marls lmestones, etc., mixed with ganic and vegetable matter, washed down by the
 mighty rivers and have been gradually deposited
 during the course of centuries. The fertiiizing
 brownish mud held in the water of the Colorado and Gila rivers resembles that from the Nile, and
 its quantity varies from O.. to 05 per cent, though the water when even considerably discolor- ed by mud is good to drink, resembling in this res
 poet the Missouri river water. 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 trifie less potassa, most phosphoric acid and car
 bonade of limestone beds through which the Colo rado passes 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 the richestfertilizing elements The soil of the valleys is extremely rich in dedomposed vegetable matter and uncombined carbon, readily absorbing the aerial gases, such especially as oxygen, which en- tering the sOil decomposes the organic matters so that they can be taken up and nourish the plants which may he considered leading feature in it's fertility. It also readily takes up and retains moisture while the rmness of its particles affords every facility for percolation and the activity of capillary action. In ts mechanical composition it's particles are in state of very fine division, which renders it more productive than coarser soils It acqufrics heat readily in the daytime, and the loss of the heat at night is very gradual, that it mains always warm and is not subject to sudden changes of heat and cold Besides its 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, phosphoric acid and potash enter into composition in the proportions best adapted to add to its fertility, though, of course, as is always the in soil analysis, it's composition varies in different localities and is not always constant.
 The soil of the uplands, or mesas, is lighter and more gravelly and in some places of free, loany, 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 or a hundred years, and improve annually, not being liable to sour, exposure to the air, after one year old, to become turbd and change color in the bottle glass.
 We can safely say that the soil of Yuma County can nowhere be surpassed containing it does all the essential elements of richness and fertility.