The Arizona sentinel., 1896-01-18

of the Gila and Colorado rivers have for the most part deep sedimentary soil of brownish, gray san1y Ioam, resting, in most places, upon gray clay subsoil at a depth of from ten to twenty feet below the surface, The clay subsoil forms hard pan which is impervious to water. These soils have been slowly formed by the decomposition of shales, sandstones, marls. limestones etc, mixed with or ganic and vegetable matter washed down by the mighty rivers and have been gradually deposited during the course of centuries. The tertilizing brownish mud held in the wat lOf the Colorado and Gila rivers resembles that from the Nile, and its quantity varies from O.1 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 wonderful similarity in the constituent parts of each. That Of the Colorado exhibiting trfc 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 artesan waters since it is constantly supplying the land with the richest fertilizing 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- terng the soil, decomposes the organic matters so that they can be taken up and nourish the plants which may Ee considered leading feature in its 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 its particles are 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 at night is very gradual, 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 or vegetable matter, sand and clay, chemical analysis shows that lime, soda, magnesa, 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, lighter and more gravelly and in some places of free, loamy, ealcareous 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 chalk than the bottom lands. It cracks and retains moisture admirably in summer. It is of that character Which will produce wine that will keep good for fifty or hundred years, and improve annually, not being liable to souri, or exposure to the air. after one year old, to become turbid and change color in the 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.