Forest Research: Open Access
Open Access

Abstract

Tree Stocking Influences Maize Biomass and Grain Yield Under Tree Intercropping Systems in Semi-arid Ethiopia

Wondwossen Gebretsadik*

Tree intercropping induces complementary interactions and enhances intercropped yield if woody components are in the right stocking and matching with herbaceous components in agroforestry systems. This study investigated the effect of tree thinning on maize crop and biomass yield in a long term tree intercropping trial. The experimental layout for the trial was RCBD with four replications having treatments including Faidherbia albida, Moringa stenopetala, Acacia nilotica, Cordia africana, mix of tree species and crop alone (control) plots. An experimental plot within a block comprised 64 trees planted at 5m spacing between trees in 8 rows and maize variety Melkassa -II was intercropped in the corridor between rows of trees. Six years later thinning that increased with in row spacing of trees from 5 m to 10 m was applied selectively on tree plots of Acacia nilotica and Cordia africana because only these two tree specieswere then found out to be fully stocked and highly surviving. Maize(Zea mays L.) was then intercropped and the influence of thinning on intercropped maize biomass, grain yield and harvest index was studied. Maize grain yield was significantly (a<0.05) affected by both the examined factors, i.e., thinning and tree species. Thinning Cordia africana has significantly influenced maize intercropped yield accompanied by 36.4% increase in yield. Maize yield and biomass under thinned Cordia africana was significantly higher (a<0.05) as compared to un-thinned plots. Grain yield and biomass of maize under un-thinned Acacia nilotica was found out to be significantly lower compared to the yield under un-thinned Cordia africana and crop alone plots (a<0.05) indicating that the species is not complementing with maize under un thinned conditions. Thinning Acacia nilotica also resulted in no significant improvement with the grain yield and biomass of maize. A significantly higher yield (a<0.05) of maize was observedunder plots of thinned Cordia africana compared to thinnedAcacia nilotic. However maize yield from crop alone plots was found higher but the difference was statistically non-significant with the yield from thinned Cordia africana plots. The harvest index of maize under thinned Acacia nilotica was significantly (a<0.05) lower as compared to un-thinned conditions. Thinning cordia africana at 130 trees/ha (25% thinning intensity) is recommended to bring a significant increase in maize biomass and grain yield that is comparable to monocropping systems.

Published Date: 2021-11-30; Received Date: 2021-11-02