DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 



25 



Table lU.— Number of bacteria per gram of soil and nitrifi/infj pover of samples from 

 plats 10, 20. 30, 40, 180, 190, 290,^ 240, 260, and 270, Truc.hee-Carson Experiment 

 Farm. 



' Plat 290 is located in an old alfalfa field one-fourth mile north of Fallon. 



DETAILED STUDY OF SOIL TYPICAL OF EXTENSIVE AREAS. 



Plats 300 to 350 are representative of a somewhat extensive type 

 of soil of the Truckee-Carson project. This soil is very unproductive 

 as a rule, almost barren in many cases, yet all through it, wherever 

 properly leveled and irrigated, are spots of a few square rods in area 

 that are normal and jjroductive. The difference between these two 

 conditions seemingly can not be explained by any of the now known 

 causes of infertihty. There is a certain difference in texture, or rather 

 in the physical properties; the productive soil is loose and sandy, 

 while the unproductive type, although sandy, contains a small quan- 

 tit}' of clay which when shaken up with water remains suspended 

 indefinitely and the soil cements on drying. These physical differ- 

 ences, while no doubt factors, do not seem adequate causes of the 

 extremely low fertility. The total alkaU content is not high enough 



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