3.5 r


N=1.0


 3.0 / / n=.u
 =4.0


 2.5



 2.0

Tons/Acre N=0.0

 1.5



 1.0



 0.5



 0.0 i i
 0 0.5 1.0 1.5 2.0 2.5
 Environmental Index = e


 FIG.VII-10. Response to environment of N treatments
 on radishes.



 Y1.5 = 1.07 + 0.72N 0.17N2 R2 = 0.74

 Y2.5 = 1.70 + 1.11N 0.24N2 R2 = 0.68

 These equations are graphed in Fig. VII-11.
 Biologically and economically, these two curves appear to
 represent different situations. In the better
 environment, production is maximized with 2.31 cwt of N.
 Maximum yield is 2.98 tons. Maximum production in the