Above and Below Ground Competition for Resources in a Sesbania and Maize Agroforestry System

Abstract

This study was conducted at ICRAF Field Research Station in
Machakos, Kenya. It was designed to determine the relative importance
of above and below ground competition between three sesbanias
(Sesbania goetzei, Sesbania macrantha, and Sesbania sesban) and maize
(Zea mays). To separate above and below ground competition, guy wiring
and root barrier were used to remove shade and root competition,
respectively, for each of the Sesbania species. Free growth, where both
roots and shade are present, was also used for each species. Sole maize
was used as control. The treatments were arranged in a randomized
complete block design with three replications. The three Sesbania species
were intercropped with maize; one row of trees followed by seven rows of
maize in each plot. Yield components of maize and light interception
were monitored for four months. The results indicated that both S.
macrantha and S. sesban negatively affected maize growth and yield.
Maize height and yield increased with distance from the trees.