MAINTENANCE OF YIEIJ) WITIIOIT MAM1:K 1<..:; 



a comparison between the crops on tlii> uimianurnl aiid the 

 completely manm'ed plot for the iirst four (or i-athn- tin- 

 second to the fifth) and the last live courses of the n.iatinn. 

 from which an idea can he obtained of how far cadi cmj) 



Unmanured Plots. 

 Fig. 41.— Crops Grown in Rotation. Rehitive Yield on Manured and Urunanurcd Plots 

 in the earlier and later years of the Kxpcrinient. 



has been affected during the fifty-six years of tli.' cxp.'iini.'ut 

 by the continued absence of niainu-c. Tlif sanu; resuhs are 

 shown graphically in Fig. 41. 



Dm-ing the last five courses llie crop of Swedes on tli.' 

 unmanured plots has averaged only 16 cwt. per acre, and tli.- 

 roots have lost the appearance of Swedes, becoming taproots 



