The Arizona sentinel., 1897-03-20

of thel Gila and Colorado rivers have for tine most part deep sedimentary soil of brownish, gray sandy loam resting, in most places upon gray cla, subsoil at a depth of from ten to twenty feet below the surface, The clay subsoil forms hard pan which is imperviors to water. These soils have been slowly formed by the decomposition of shales, sandstones, snars. limestones, etc., mixed with ganic and vegetable matter, washed down by the mighty rivers and have been gradually deposited during the course of centuries. The fertilizing brownish mud held in the wat 'lof the Colorado and Gila rivers resembles that from the Nile, and its quantity varies from O. to o.5 per cent, though the water when even considerably discolor- ed by mud is good to drink, resembling in this pect the Missouri river water. A chemical analysis of the sediments of the Colorado and of the Nile exhibits a wonderful similarity ia the constituent parts of each. That of the Colorado exhibiting Q trihe less rotassa, most phosphoric acid and bonede oflimestome 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 fertilizng 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 be considered leading feature in its fertility. It also readily takes up and retains moisture while the rmness of It's particles affords every facility for pefcelation and the activity of capillary action. In Its mechanical composition it's arS; in oF 6na renders it more productive than coarser soils It acqurics heat readily in the daytime, and tke loss of the heat at night is very gradual, that 1t mains always warm and is not subject to sudden changes of heat and cold Besides it's essential con- stituents of water, organic vegetable matter sand and clay, chemical analysis shows that lime soda, magnesa, iron ammonia and available forms of nitrogen, phesphoric acid and potash enter into composition in the proportions best adapted to add to its fertility though of course, is alwaJ the in soil analysis, it's composition varies in different localities and is not always constant.
 The soi the uplands, or mesaS, lighter and more gravelly and in some places of 2 lree, loamy calcareous character. The mesa lands are warm and generous. They seem especially adapted for the grape, olive and citrus fruits generally. Their so contains more magnesia, lime or chalk than tho bottom lands. It cracks and retains moisture admirably in summer It is of that character whicf will produce wine that will keep good for fifty ol hundred years, and improve annually, not being liable to sour exposure to the air, after ont year old, to become turbd and change color in tho bottle glass.
 We can safely say that the soil of Yuma County can nowhere be surpassed, containing as it does all the essential eiemehts of richness and fertility.