Influence of soil inoculation with vesicular-arbuscular mycorrhiza and a phosphate-dissolving bacterium on plant growth and 32P-uptake

The influence of inoculation of soil with a vesicular-arbuscular mycorrhizal fungus (Glomus fasciculatus) and a phosphate-dissolving bacterium (Bacillus circulans) on phosphate solubilization, growth of finger millet (Eleusine coracana) and phosphorus uptake from 32P-labelled tricalcium phosphate and superphosphate were studied. The mycorrhizal plants produced more dry matter and removed more 32P from the soil than non-mycorrhizal plants, but did not show increased 32P activity per unit plant mass. The 30 mm NH4F-HCl extractable 32P (available 32P) in soil, plant 32P activity and total P uptake were enhanced by soil inoculation with the bacterium. In the treatment receiving both inocula a synergistic effect was recorded with increased P uptake and dry matter production.