SPRING CEREALS AT MORO, OREG. 5 



Table I.— Composition of silt loam soil in the Columbia, Basin. 



Constituents. 



Total. 



Soluble 



in 



1.115 HCl. 



Constituents. 



Total. 



Soluble 

 In 



1.115 IK 1. 



Silica (Si0 2 ) 



Per cent. 



62.85 



1.63 



4.52 



1.94 



.04 



Per cent. 



0. 34 



.74 



3.05 



1.06 



Iron and aluminum oxids 



Per cent. 



8. 17 



.30 



.11 

 .37 



Per cent. 



Potash (K»0) 



8.37 



Lime(CaO) 



Phosphoric acid (P2O5) 



.21 





















From analyses of surface soil obtained from both virgin and cropped 

 areas Bradley concludes that "while the percentage of nitrogen in 

 these soils has remained practically constant under continual crop- 

 ping for, in extreme cases, 25 years, there has been a marked decrease 

 in the carbon or organic content." Probably on account of this 

 deficiency in humus the surface soil at the substation is inclined to 

 run together or pack in the spring from the effects of winter precipi- 

 tation. 



The soil is remarkably uniform in texture, absorbs water readily, 

 and has a high moisture-holding capacity. At the substation the depth 

 of the soil to the rock formation underneath varies from 1 to 9 feet, 

 the deeper soil being on the higher elevations and on the northward 

 slopes. Where the ground slopes toward the west or southwest, the 

 soil usually is shallow and therefore less suited to cereal production, 

 because of its inability to store sufficient moisture to mature crops. 

 Most of the farm had been cropped to grain for about 25 years prior 

 to the establishment of the substation. 



CLIMATIC CONDITIONS. 



Careful records of climatological phenomena have been kept since 

 January, 1910, in cooperation with the Biophysical Laboratory of 

 the Bureau of Plant Industry. The weather-observing equipment 

 consists of standard snow and rain gauges, maximum and minimum 

 thermometers, self-recording thermographs, an evaporation tank, 

 an anemometer, and a psychrometer. 



PRECIPITATION. 



In no other place in the world is cereal production conducted on 

 such an extensive scale with so little precipitation as in the Colum- 

 bia Basin. As Table II shows, the lowest annual precipitation 

 in the vicinity of Moro during the past 10 years has been 7.68 inches. 

 The precipitation for the years from 1905 to 1909, inclusive, was 

 recorded at Grass Valley, which is about 10 miles south of Moro, 

 while that for the years 1910 to 1915, inclusive, was recorded at the 

 substation. The average amiual precipitation for the 11-year period 

 from 1905 to 1915 is 11.35 inches. The highest annual precipitation 

 since records have been kept at the substation is 14.89 inches. 



