The effect of intercropping Sclerocarya birrea (A. Rich.) Hochst., millet and corn in the presence of arbuscular mycorrhizal fungi

Abstract

Sclerocarya birrea (A. Rich.) Hochst. (marula) is native to Africa occurring in the semi-arid, deciduous savannas of much of sub-Saharan Africa. It has multiple uses, including the fruits, kernels, oil, bark, wood and leaves which make it a key species to support the development of rural enterprises. Enhancing positive interactions between marula and other crops is key to successful introduction of marula into the farming systems in the arid and semiarid areas of Africa. The objective of the study was to determine the influence of various combinations of marula, Pennisetum glaucum (L.) R. Br. (millet) and Zea mays (corn) with one another when inoculated with arbuscular mycorrhizal (AM) fungi. A threechambered acrylic root boxes were used. One outer chamber contained seedlings of S. birrea while the other contained millet or corn or bare soil. The central chamber was either inoculated with an AM fungus (Gigaspora margarita Baker and Hall) or uninoculated. Inoculation in the presence of the two crops enhanced both biomass production and height growth of marula seedlings. Both hyphal density and number of spores in marula compartments were increased under intercropping system compared to marula monoculture. The study demonstrated that intercropping marula with millet or corn could help in the propagation of AM fungi spores in the soil which would enhance marula establishment especially in soil with low phosphorous and moisture scarcity.