34
70
60 FP.
50
40 TSP
, 30'
S.o* '-'-"= . -: 
... CM
o ...- ....-**Pcw
0
0.8 1 1.2 1.4 1.6 ,1.8 2 2.2
ENVIRONMENTAL INDEX, El
WL SF3 SF PF SF PF PF
31 1 21
LAND CLASSES
Figure 9. Cowpea response (KG/SCC) of four treatments to environment
Manaus, Brazil, 1990 (Singh)