Improvement of wheat and maize crops by inoculating Aspergillus spp. in alkaline soil fertilized with rock phosphate

Abstract

Aspergillus tubingensis and A. niger were isolated from the landfills of rock phosphate mines and tested for their efficacy to solubilize rock phosphate (RP), and improve plant growth and phosphate (P) uptake by plants grown in soil amended with RP. The results showed that they effectively solubilized RP in Pikovskaya's (PKV) liquid medium and released significantly higher amounts of P into the medium. A. tubingensis solubilized and released 380.8 μg P mL⁻¹, A. niger showed better efficiency and produced 403.8 μg P mL⁻¹. Field experiments with two consecutive crops in alkaline agricultural soil showed that inoculation of these fungi along with RP fertilization significantly increased yield and nutrient uptake of wheat and maize plants compared with control soil. P uptake by wheat and maize plants and the available P increased significantly in the RP-amended soil inoculated with fungi compared with control. These results suggest that the fertilizer value of RP can be increased, especially in alkaline soils, by inoculating P-solubilizing fungi.

Keywords:

• Aspergillus tubingensis
• A. niger
• fertilizer value
• inorganic P
• nutrient uptake

Acknowledgements

The authors are thankful to University Grant Commission for financial assistance and TIFAC-CORE for facilities.