DIVISION OF SOILS. 



67 



racy and detail of the base maps. The pressure for the work lias 

 been so great from many districts that the limited means at the dis- 

 l^osal of the Division and the few trained men available to head the 

 field parties have made it necessaiy to shift the parties in the field 

 more than would otherwise have been advisable. It requires about a 

 month for a party to get well started and clearly see the problems 

 presented in a district and to work out the kej^ to the situation. In 

 three months the work is going very smoothly, rapidly, and in most 

 eases satisfactorily. If then we are forced to shift them to a new 

 field to meet an urgent demand, much valuable time is lost and expe- 

 rience Avasted. Wherever possible a party should be left in one dis- 

 trict for an entire season of six to eight months, then they should be 

 allowed from three to six months to prepare their report and to work 

 up in the laboratories special problems which constantly present them- 

 selves in the field. If left thus undisturbed, and with good maps, 

 each party should survey and map from 800 to 1,000, or j)erhaps as 

 high as 1,500 square miles in a field season, or from 500,000 to 1,000,000 

 acres, in such detail that every 10-acre field Avill be accuratelj' located 

 and properly classified. 



DETAILS OF THE SOIL SURVEY. 



The following table gives the area, rate, and cost of the soil survey 

 which has been carried on during the fiscal year: 



Aieas surveyed and mapped and cost of same during fiscal year ending June SO, 



1000. 



This work has been done by five field parties, much of it in the 

 spring of the present year. The work will be reported in some detail 

 to show the importance of the economic problems involved, as well 

 as the large amount of useful information collected and the assist- 

 ance rendered the several districts. 



The Means partij . — In .July and August Mr. Means made some recon- 

 noissances in Utah and Colorado in preijaratiou for further detailed 

 work in those States. In December he went to Arizona, where the 

 Arizona experiment station furnished an assistant, and three months 

 were spent in surveying and mapping 400 square miles of land in 

 cooperation Avith the experiment station. 



In the 100 square miles of land surveyed and mapped around Tempe, 

 Ariz., on the south side of the Salt River, the soils were found to be 

 formed of wash from the mountains and alluvial material brought 

 down by the river. The underlying material was calcareous, and 

 underlying this at still greater depths were gravel and bowlder beds, 



