The optimal soil pH for maximizing dry matter yields of leucaena lines was around 6.5 for Piracicaba and Campina Grande, and around 7.0 for Peru, Ishigaki, K-8, and Cumningham.
　The range of the optimal soil pH was very narrow for Ishigaki, but contrastingly wide for K-8, indicating its ability to grow well in acid soil. Both forage N and digestible dry matter yields were in parallel to the dry matter yields as percent N and IVDMD in the forage fraction were not different with the lines tested.
　These results indicate that Ishigaki, Peru, and Cunningham are suitable for growing on Calcareous Regosols, Campina Grande and Piracicaba on Reddish Brown soils and K-8 on Red-Yellow soils of the South-Western Islands of Japan.