Twelve erosion plots each measuring 50 m long and 3 m wide
were used for the study. The plots were planted with cassava and maize in a simple crop mixture. The
runoff, soil loss and crop yield were assessed under the four treatments. The rainfall lost as runoff with
no vetiver (control plot) was 24.8 % compared to 7.7, 11.5 and 11.6% lost on the green structure plots
at spacings of 5, 15 and 25 m, respectively.