16 



IMPROVEMENT OF THE WHEAT CROP IN CALIFORNIA. 



Table I. — Effect of deep plowing and green-manure crops on the yield of wheat at 



Modesto, Cal., 1909. 



No. 



of 



plat. 



Preceding treatment or crop. 



Fallow 



Horse beans (turned under) 



Canadian field peas (turned under) 



Wheat (26 bushels) 



Rye and vetch (turned under) 



Rye (turned under) 



The cultivation of the plats indicated in the table was as follows: 

 In the fall of 1907 all of the plats were laid out on summer-fallow 



Fig. 5.— Wheat growing on plat on which rye was grown and plowed under in 1908. (See figure 1, F.) 



land and all were plowed to a depth of 6 inches and harrowed. Plat 

 1 was allowed to remain fallow. Plat 4 was sown to wheat. Plats 

 2, 3, 5, and 6 were sown, as indicated, to horse beans, Canadian 

 field peas, rye and vetch, and rye alone. The vetch in plat 5 made 

 a very poor stand, while the horse beans and peas made a fairly good 

 stand. The stand of rye was excellent. 



In March, 1908, plats 1, 2, 3, 5, and 6 were plowed 8 inches deep, 

 harrowed, and kept clean throughout the summer and fall. Plat 4, 



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