WHEAT GROWN IN EOTATION 65 



percolation was only 4 inches, and the total produce on the 

 wheat after fallow plot was 2743 Ib. as against 1810 Ib. on 

 the continuous wheat plot, or a gain of 933 Ib. due to 

 fallowing. 



For the wet autumns, however, with an average rainfall of 

 13*66 inches and a percolation of 8 '92 inches, the wheat after 

 fallow yielded 1757 Ib. against 1627 Ib. on the continuous 

 wheat plot, or a gain of 130 Ib. only due to fallowing. 



It will be seen that the bare fallow increased the wheat crop 

 coming after it by nearly 52 per cent, when a comparatively dry 

 autumn succeeded the fallow, but the increase was less than 8 

 per cent, when there was much rain and percolation after the 

 summer fallow. 



It is interesting to compare these two plots, both without 

 manure, with the continuously unmanured plot in the Agdell 

 field, which comes into wheat once every four years in the 

 course of the rotation (see p. 190). The plot in question has 

 received no manure since 1852 ; it is cropped on a four-course 

 rotation, beginning with turnips which are completely removed 



TABLE XXVI. Wheat grown without Manure at Eothamsted. (1) Grown 

 continuously ; (2) In alternation with Fallow ; (3) In Four-course 

 rotation. Average for the 15 years (1855, '59, '63, '67, 71, 75, 79, '83, 

 '87, '91, '95, '99, 1903, 1907, and 1911). 



* Now called Plot 5. 



from the land, after the turnips barley is taken, then comes a 

 season of bare fallow before the wheat. It will thus be seen 

 that three crops are removed in the course of the four years, 

 but so very small is the turnip crop that practically the land is 

 cropped only every other year. For the fifteen years during 

 which comparison is possible, the average crop of wheat grown 

 thus in rotation on continuously unmanured land has been 26*9 



E 



