Finally, an important finding from this study is that we were
able to apply the diversity–productivity relationship from plant
community theory, which is based upon plant biomass, to an
agricultural ecosystem using fruit yield. These findings that three
and four species combinations consistently overyielded with
regard to fruit production in this system of peanut–watermelon–
okra–cowpea–pepper are consistent with findings of overyielding
of plant biomass in natural ecosystems (Tilman et al., 1996;
Reich et al., 2004).