BUREAU OF PLANT INDUSTRY. 321 



in the paragraphs which follow, have been in operation for three 

 years or more, while work on the other stations was inaugurated 

 during the summer of 1909. 



Yuma experiment farm. — The Yuma station, of which Mr. W. A. 

 Peterson is superintendent, includes 154 acres of land, 7 miles north 

 of Yuma, Ariz., on the California side of the Colorado River. The 

 experimental work, which up to the present year has been conducted 

 on rented land south of Yuma, has now been brought together on this 

 new experiment farm. The different lines of work under way include 

 Egyptian cotton, dates, miscellaneous forage crops, various kinds 

 of fruits, and experiments with eucalypts in cooperation with the 

 Forest Service. Owing to the necessity of clearing and preparing 

 for irrigation all of the land required for the experimental work this 

 year, the work has been considerably impeded. The station is now 

 fairly well developed, however, and the experimental work will go 

 forward rapidly. 



Truckee-Carson experiment farm. — The Truckee-Carson station, 

 of which Mr. F. B. Headley is superintendent, is located on the 

 Truckee-Carson project of the Eeclamation Service, 1 mile south of 

 the town of Fallon, Nev. The station farm includes 160 acres of 

 land, of which about 50 acres have been leveled and put under ditch. 

 Cooperative experimental work with forage crops, cereals, corn, hor- 

 ticultural and truck crops, and forest trees has been continued during 

 the j^ear. New lines of cooperative investigational work dealing with 

 the causes of the infertility of the raw desert land have been begun 

 during the past year. These investigations include studies of the 

 bacterial flora of the soil and of certain physical and physiological 

 phases of plant nutrition. Experiments in the application of ferti- 

 lizers have also been started. 



San Antonio experiment farm. — The San Antonio station, of 

 which Mr. S. H. Hastings is superintendent, includes 125 acres of 

 land, 5 miles south of San Antonio, Tex. The lines of cooperative 

 investigational work mentioned in previous reports have been con- 

 tinued, with added emphasis during the past year on studies of native 

 plants related to the cultivated fruit and nut trees. The aim of the 

 work at San Antonio is chiefly to determine what crops and what 

 tillage methods are likely to produce the best results without irriga- 

 tion. The season of 1909 was tlie driest year recorded during a period 

 of over thirty years; consequently an excellent opportunity was af- 

 forded for determining the efficacy of improved methods of tillage 

 and the relative value of various crops. The most significant feature 

 of the season's work was the demonstration of the value of a pro- 

 longed fallow period preceding crop production. Land that had lain 

 fallow and had been thoroughly cultivated for twelve to eighteen 

 months prior to cropping in 1909 gave very satisfactory yields of 

 corn, sorghum, and cotton, while other land which had lain fallow for 

 a much shorter period produced practically no crop. The difference 

 in soil moisture content in the two fields appeared to be hardly suffi- 

 cient to account for the difference in yields. Experiments have been 

 begun to determine what factors otlier than available moisture supply 

 contributed to those observed differences in crop yield resulting from 

 a longer period of fallow. 



73477°— AGB 1910 21 



