66 



EXPERIMENTS UPON WHEAT 



bushels per acre, as against 17 '2 bushels for wheat after fallow 

 and 11*8 bushels for continuous wheat. 



It is difficult to explain this superiority of the wheat grown 

 in rotation over the wheat after fallow. There are no more 

 residues in the land in the one case than in the other, the land 

 is equally clean and has similarly received a summer fallowing 

 before the wheat crop. In the case of the rotation plot, however, 

 the particular stratum of soil usually occupied by the wheat 

 roots is only drawn upon once in four years, the intermediate 

 crop being the much shallower-rooted barley. 



III. TRIALS OF VARIETIES OF WHEAT. 



In the eleven years 1871-1881, trials were made of about 

 twenty varieties of wheat under the ordinary conditions of 



TABLE XXVIlA. Varieties of Wheat grown at Rothamsted. Produce of 

 Grain per acre (bushels). Results arranged in order of highest average 

 yield. 



