The Arizona sentinel., 1898-12-03
LANDS AND SOILS.

The lands of Yuma County comprise the river bottoms and valleys and the uplands or mesas The bottom ands moister and slightly mere fertile if, indeed it is possible to make comparisons where all so wonderfully productive and prolific The uplands mesas are warmer and, perhaps, lightly for betterthe cultivation the citrus fruits Yuma contains variety of soil The valley land of the Gila and Colorado rivers have for the most part deep sedimentary soil of brownish, gray sandy lOam, resting, in most places, upon gray clay subsoil at depth of from ten to twenty feet below the surface, The clay subsoi forms a 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 fertilizing brownish mud held in the wat tIof 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 W hen considerably discolor- ed by mud is good 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 a
 
 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 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 so that they can be taken up and nourish the plants which may be considered @ leading featurs in 1t fertility. It also readily takes up and retains moisture, while the rmness of it's particles affords every facility for percolation and the activity of capillary action. In ts mechanical composition it's particles are in a state of very fine division which | renders it more productive than coarser soils acquires heat readily in the daytime and the loss of the heat at night is very gradual so that it re- mains always and is not subject to sudden changes of heat and cold Besides it's essential con stituents of water, organic or vegetable matter, sand and clay, chemical analysi shows that ime 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 is always the case in soil analysis it's composition varies in l different localities and is not always constant
 The soi the uplands, or mesas, lighter and more gravelly and in some places of a lree, loamy calcareous character. The mesa lands are warm and I 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 cracks and retains moisture admirably in summer If 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, or on exposure to the air, after year old to become turbid and change color in tho | bottle or glass