Bui. 103, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate II. 



Fig. 1.— Field Showing the Type of Summer Fallow Main- 

 tained IN Every Other Series on the San Juan County 

 Arid Farm. 



Fig. 2.— The Interior of an Alfalfa Plat on the San Juan 

 County Arid Farm. 



