Effect of Bacillus subtilis on phosphorus uptake by cucumber as affected by iron oxides and the solubility of the phosphorus source

Authors

• Ana Maria Garcia-Lopez Universidad de Sevilla
• Antonio Delgado Universidad de Sevilla

DOI: https://doi.org/10.23986/afsci.56862

Abstract

In this work, we examined the effects of Bacillus subtilis strain QST713 by assessing plant P uptake from variably P compound .The experiment performed involved three factors: (i) P source [KH₂PO₄ at 100 mg kg^–1, and phosphate rock (PR) at 100 or 200 mg kg^–1]; (ii) plant inoculation with QST713 (inoculated and non-inoculated); and (iii) Fe oxide (ferrihydrite) in the growth medium (0 or 300 mg kg^–1 concentration of citrate–ascorbate-extractable Fe). Ferrihydrite decreased dry matter yield in plants by more than 50 %. Inoculation with QST713 increased plant growth, and total accumulation of P and P uptake in plants. Overall, QST713 increased P uptake by 40 %, the effect being independent of the presence of ferrihydrite and P source. The increased P uptake observed can be ascribed to increased solubilization of P and to increased root growth. Therefore, QST713 improves P nutrition in plants grown on media with a high P adsorption capacity irrespective of the solubility of the P compound.