60 



THE ROTHAMSTED EXPERIMENTS. 



TABLE 18. — Mangel-Wurzel. Sugar per cent and per acre per 

 annum in the roots. Average of 4 years, 1877-80. 



SUGAR PER CENT IN THE ROOTS. 



Farmyard manure , 

 Farmyard manure and\ 

 superphosphate / 



Superphosphate . 



Superphosphate and po-\ 

 tassium sulphate J 



Superphosphate, potassi-^ 

 um, and magnesium I 

 sulphates, and sodium | 

 chloride 



Mean of 6 and 4 



SUGAR PER ACRE, LB. 



INCREASE OF SUGAR PER ACRE OVER SERIES 1. 



LB. INCREASE OP SUGAR FOR 1 LB. NITROGEN IN MANURE. 



5 

 6&4- 



Superphosphate 

 Superphosphate and po- 

 tassium, &c. 



17.1 



20.7 



8.5 

 17.8 



5.0 

 12.8 



