The Arizona sentinel., 1896-08-15

of sbei Gila and Colorado rivers have for the most part deep sodimentary soil of brownish, gray sandy loan, resting, in most places, upon 8 gray clay subsoH at depth Of from ten to twenty feet below the surface, Tbe clay sUbsoil forms a hard gan which is apervious to water. These soils have been slowly formed by the decomposition Of shales Sandstones, marls. limsstones, etc. mixed with or ganic and vegetable matter, washed down by the mighty rivers and hare been gradually deposited during the course of centuries. The fertilizjng brownish mud held in the wat t1of the Colorado and Gila rivers resembles that from the Nile. and its quantity varies from 0.l to 0.5 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 wonderful similarity in the constituent parts of each. That of the Colorado exhibiting a trife less potassa, most phosphoric acid and car bonadc of limestone beds through which the Colo rado passas In other respects the sediment of the Colorado is almost identical with tbat 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 richestfertilzing 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 that they can be taken up and nouyish the plants which may De considered leading feature 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 its particles are in state of very fine division, which | renders it more productive than coarser soils It acquires 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 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 it's fertility though, of course, is always the case in soil analysis, its composition varies in different localities and is not always constant.
 The soi the upands, or mesas, lighter and more gravelly and in some places of tree, 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 Esagnesia, lime 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 hundred years, and improve annually, not being liable to sour, exposure to the air, after one year old to become tuTbid and change color in the bottle or glass.
 We can safely say that the soil of Yuma County can nowhere be surpassed, containing it does all the essential clements of richness and fertility.