SOILS 25 



particularly well adapted to lima beans and the industry 

 has been extensively developed on these soils. The Pla- 

 centia series is used for beans and other vegetables. The 

 fine sandy loam of the Sacramento series is valued for 

 vegetables and the loam of this area is also used. The 

 sandy types of the Salem series are good vegetable soils. 

 When irrigated, the San Joaquin series are valuable 

 trucking soils, and vegetables are grown to some extent 

 on the Stockton series. There are 110,163 acres of muck 

 and peat soils of the Pacific Coast valued for the crops 

 usually grown on these lands. Puget clay soil and Puget 

 fine sandy loam have deficient drainage, but when well 

 drained and protected from overflowing, truck crops and 

 potatoes are successfully grown. Puget silt loam gives 

 promise of becoming a highly prized soil for small fruits 

 and vegetables. 



59. Soil texture. It will be seen from a study of vari- 

 ous soil types cited that the value of a soil for trucking 

 purposes is determined largely by its texture. The value 

 of a soil for very early truck depends mainly upon the 

 amount and size of sand. That is, coarse sand is a 

 "quick" soil, because it is well drained and dries out and 

 consequently warms up very early in the spring, and 

 makes early planting possible. Again, the coarse sands 

 are warmer during the entire period of growth, thus has- 

 tening early maturity. Such soils require a large amount 

 of vegetable matter. Liberal fertilizing and irrigation 

 are usually a great advantage. The medium sands are not 

 quite so early, but are more productive and somewhat 

 more retentive of moisture and plant food. The fine 

 sands are often our best trucking soils. Although not 

 quite so early as the coarse and the medium sands, they 

 are usually more productive. The silt and the clay soils 

 are often valuable for late crops, and the maintenance of 

 fertility is less expensive on the heavier types. 



60. Advantages of sand. The soils of the most impor- 



