The Arizona sentinel., 1895-06-22

the Gila and Colorado rivers have for the most
 part a deep sedimentary soil of brownish, gray
 sandy To m, resting, in most places, upon gray
 clay subsoil at a depth of from len 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
 glnic 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 tIOf the Colorado and Gila rivers resembles that from the Nile, and its quantity varies from 01 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 in the constituent parts of each. That of the Colorado exhibiting trihe less potassa, most phosphOrc 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 richest ertilizng elements The soil of the valleys is extremely rich in dedomposed vegetable matter and unco ,bined c,rbon readily absorbing the aerial gases, such especially, oxygen, which en- tering the soil, decomposes the organic matters that they can be taken up an nourish the plants which may ne considered a leading featur, in its fertility. It also readily takes up and retains moisture while the frmness ofits particles affords every facility for percOlation and the activity of capillary action. In ts mechanical composition its particles in a state of very fine division which renders it more productive than coarSer soils It acquries heat readily in the daytime and the loss of the heat at night is very gradual, that itre mains always warm and is not subject to sudden changes of heat and cold. Besides it's 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, phosphoric acid and potash enter into composition in tn proportions best adapted to add to it's fertility though of course as is always the case 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, czlcareous 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 produc a 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 turbid 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.