MANAGEMENT OP GENEEAL FAEMS IIST OEEGON. 3 



farming crop yields gradually declined. The average yield of wheat 

 for the WiUamette Valley during the early eighties was not far from 

 17 bushels per acre. The United States Census report shows that the 

 average yield of wheat for Benton, Clackamas, Lane, Linn, Marion, 

 Multnomah, Polk, Washington, and Yamhill Counties for the year 

 1880 was 14.9 bushels per acre. 



The practice of summer fallowing from one-fourth to one- third of 

 the land each year and the production of wheat and oats to the 

 exclusion of almost all other field crops has prevailed on the red hill 

 or clay type of soil to the present time. On the sdt loam or '' val- 

 ley" soil, on the other hand, radical changes in the type of farming 

 have taken place. Clover and vetch were introduced during the 

 eighties and early nineties, and the practice of summer fallowing 

 has practically been abandoned on this type of soil. The influence 

 of these leguminous crops on crop yields and the efficient management 

 of these farms will be shown in the tables which follow. 



TYPES OF SOIL. 



The 212 farms which constitute the basis of this study are located 

 on two distinct types of soil, Salem silt loam and Salem clay. ^ The 

 Salem silt loam is locally known as ''valley" or ''prairie" soil. It 

 occupies the level and gently rolling vaUey lands. The soil is a brown 

 to black silt loam, 18 to 24 inches deep. The subsoil is a yellowish 

 to red clay loam which becomes heavier with the depth. The Salem 

 clay type is locally known as "red hill" soil. It occupies a series 

 of rolling hills on either side of the "valley" or silt loam soil. The 

 Salem clay soil consists of 12 to 15 inches of red clay, which is under- 

 lain by a clay of much the same color and texture as the surface 

 soil. 



DEFINITIONS OF TERMS USED. 



Definitions of some of the terms used in this discussion may be 

 found helpful in studying the tables which follow. 



Improved land. — -The usable portion of the farm. It includes the 

 tillable area and any portion of the farm that has been improved 

 sufiiciently to furnish fairly good pasturage. 



Rotation area. — ^That portion of the farm upon which field crops 

 are changed about from year to year. It includes the areas in field 

 crops, summer fallow, and pasture in rotation. It does not include 

 the area in fruit and garden. 



Field-crop area. — That portion of the farm occupied by the field 

 crops. 



1 Salem silt loam and Salem clay are terms applied to these soils by the Bureau of Soils, U. S. Depart- 

 ment of Agriculture, when making a soil survey in Marion and Polk Counties, 1903. 



