The Arizona sentinel., 1896-08-01

of she Gi!a and Colorado rivers have for the most part a deep sedimentary soil af brovniyh, gray san r b m, resting, in most places, upon gray clay subsoil ct a depth of from ten to twenty feet below the surface, The clay subsoil forms hard pan which is impervious to water Those soils have been slowly formed by the decomposition Of shales, sandstones, rarls. limestones etc, mixed with or ganic and vegetable matter, waahed down by the mighty rivers and have beeu gradually deposited during the course of centuries The fertilizing brownish mud held iii the wat ,Iof the Colorado and Gila rivers resembles that from the Nile, and is quantity varies from O.1 to 0.5 per cent
 though the water when even considerably discolor- ed by mud is good to drink, resembling in this req pect the Missouri river water. chemical analysis of the sediments of the Colorado and of the Nile exhibits wonderful similarity in the constituent parts Of each. That Of tIe Colorado exhibiting trife less potassa, most phospho-ic acid and car bonade of limestone baGs through which the Colo rado passos. En other respects the sediment of the Colorado is almost identical with that of the Nile It viii 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 richestiertilizng 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 anl nourish the plants which may be considered a leading feature in its fertility. It also readily takes up and retains moisture while the frmness 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 acquircs heat readily in the daytime end 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 it's essential con- stituents of water, organic vegetable matter sand and clay, chemical analysis shows that line soda, magnesia, iron, ammonia and available forms of nitrogen, phosphoric acid and potash enter into composition in the proportions best adapted to add to it's fertility, though, of course as is always the casa in soil analysis, its 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 ,ree Ioamy 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 a 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 turbd 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 elements of richness and fertility.