Greenhouse evaluation of two woody hedgerows as affected by arbuscular mycorrhizal fungus (AMF), soil quality and moisture

Abstract

Using a 2 × 2 × 2 factorial experiment in a completely randomized design with three replicates under greenhouse conditions, we evaluated the growth of Gliricidia sepium and Leucaena leucocephala in sterile top and sub-soil in combination with arbuscular mycorrhizal fungus (AMF) and rhizobia inoculations under two watering regimes. The factors were: AMF (Glomus deserticola) inoculation (inoculated and non-inoculated), watering regimes (adequate watering and water stressed) and two soils (topsoil and subsoil, with the latter representing a simulated degraded soil). The AMF colonization ranged from 27.3 – 47.3% and was significantly reduced by water stress in both hedgerow species under the two watering regimes. The growth, biomass yield, nutrient uptakes and physiological responses of Leucaena benefited from AMF inoculation in the two soils under the two watering regimes while Gliricidia responded to AMF inoculation when conditions were more stressful. Nodule dry weight of G. sepium was significantly improved (from 300 – 2500%) in the subsoil under both watering regimes. AMF inoculation compensated for the negative effect of subsoil when compared to the non-inoculated topsoil. Responses observed in the present investigation due to AMF inoculation, particularly in the subsoil, points to the potential of this technology in the reclamation of degraded tropical soils.

Keywords:

• Arbuscular mycorrhizal fungus
• degraded soils
• Gliricidia sepium
• Leucaena leucocephala
• moisture
• yield

Acknowledgements

We are grateful to Alley Farming Network for Tropical Africa (AFNETA) for the provision of grant for this research. The first author wishes to thank Prof. Rosendahl and Dr Kjoller for critically reviewing the draft manuscript.