There was a difference between the experiments in the two countries in the effects of main-plot (shade) and subplot (coffee management) treatments on total SOC stocks (Mg C ha−1). In Costa Rica the ANOVA showed significant (p < 0.01) overall effects of both on the change in SOC stock at 0–10 cm depth over the 9-year period. However, in deeper soil only the shade treatment effect remained significant and there was an additional significant (p < 0.01) effect of initial C concentration at the 20–40 cm depth. In contrast, in Nicaragua the ANOVA showed no significant effects of main-plot treatment or subplot treatment or of initial C concentration at any soil depth.
ANOVA
p
< 0.01
SOC stock
depth
0–10 cm
cm
change in SOC stock
period
over the 9-year
year
SOC stock
depth
20–40 cm
effect of initial C concentration
p
< 0.01