Maize grain yield under taungya system with different multipurpose trees at Bako, western oromya

A two-year taungya experiment consisting of ten different multipurpose tree species intercropped with maize was conducted at Bako Agricultural Research Center, Western Oromia, Ethiopia. The objective of the study was to assess the possibility of utilizing the idle growing space usually occurring during the early stage of tree establishment. The tree species evaluated were Markhamia lutea, Calliandra calothyrsus, Chamaytisus palmensis, Erythrina brucei, E. abyssinica, Acacia cyanophyla, A. mearnsii, A. melanoxylon and Moriinga oleifera. The experiment was laid out in Randomized Complete Block Design with two replications. Results showed that there was no significant difference in grain yield of the intercropped maize with different tree species during the first year of tree establishment, but was significantly affected by the intercropped trees (p less than or equal to 0.05) during the second year. (This may be because at the age of one year the trees are at seedling/sapling stage (shorter) and hence pose relatively little shading problem on the intercropped maize, which was also evidenced by correlation analysis. During the first year, maize yield was not significantly correlated with tree height, root collar diameter, and survival, unlike the second year where there was significant negative correlation between maize yield and tree height (r = -0.52; p = 0.019), root collar diameter (r = 0.49; p = 0.027) survival rate (r = 0.493; p =0.027). Based on this preliminary finding, maize can be intercropped with newly established trees in a sort of taungya system during the first year without considerable reduction in grain yield so that the idle growing space can be utilized to the maximum, and this can be one way of achieving food security in the area. In addition, even if there is a reduction in yield during the second and more years, the over all productivity of land could be increased with the use of taungya system.