SOIL SURVEY OF SOLOMONSVILLE AREA, ARIZONA. 



13 



outward from the normal position near the valle\* trough. The soil 

 grades, often very quickly, into the Pecos sand and the Maricopa silt 

 loam. 



Occupying the lower parts of the valley, this soil type is generally 

 level and has little surface variation, although sometimes slightly 

 pitted and cut by river flood channels. It usually lies several feet 

 above the stream level. When not separated from stream courses by 

 areas of other soil t}-pes it is set off from the stream by vertically 

 eroded terraces. In the native vegetation cottonwood and willow pre- 

 dominate. This soil does not readily bake or puddle, except where it 

 lies next to areas of the Maricopa silt loam and other soils containing 

 a considerable admixture of silt and clay. While it retains moisture 

 well and does not leach as readily as the Pecos sand, it allows the 

 ready percolation of water. The usual underlying deposits of sand 

 and gravel furnish good natural drainage. Artificial drainage is nec- 

 essary only in a few localities where seepage water has collected from 

 the drainage of adjacent soils or from the use of excessive quantities 

 of water in irrigation. 



The origin of this soil and the agencies prominent in its formation 

 are similar to those of the Pecos sand, the proportion of the finer 

 alluvial material here being considerably greater. 



The Gila fine sand}- loam carries considerable mica, which greatly 

 increases its porosity and counteracts the binding effects of the heav-^ 

 ier sediments. The mineral plant foods are usually present in suffi- 

 cient quantities and the soil is usually rich in organic matter. Owing 

 to low position and marked capillary power the soil carries small 

 quantities of alkali salts. Except where there is considerable seepage 

 from higher levels these are not present in alarming quantities. 



This is one of the most fertile and valuable soils of the valley, pro- 

 ducing large crops of wheat, barley, and alfalfa. It is well adapted 

 to the culture of fruit, especially apples, as well as to sugar beets, 

 alfalfa, and grains, including wheat, barley, corn, and sorghum. 



The following table shows the results of mechanical analyses of this 



soil: 



Mechanical analyses of Gila fine sandy loam. 



