Phosphorus solubilizing Bacillus sp. strain MN-54 increased the yield and economic returns of pearl millet due to improved phosphorus use efficiency

Abstract

Phosphorus (P) deficiency is a frequent problem in calcareous soils of Pakistan because of P-fixation, which poses significant threats to pearl millet productivity. The use of P-solubilizing bacteria (PSB) is regarded as a promising approach for improving P-availability in soil-plant systems. However, it needs optimization of P application into the soil. Therefore, this 2-year field study was conducted to optimize P doses in combination with PSB (Bacillus sp. MN54) inoculation to improve phosphorus use efficiency (PUE), yield, economic returns, and grain quality of pearl millet. Five P doses, i.e. 0 (native soil P only - control), 30, 60, 90, and 120 kg P₂O₅ ha⁻¹ combined with and without PSB inoculated seeds were used in the study. The application of 90 kg P₂O₅ ha⁻¹ + seed inoculation with PSB improved the grain yield by 36.8% and 36.0% during 1st and 2nd year, respectively. The same treatment significantly improved the PUE, grain protein, zinc (Zn), and total grain P contents compared to the control treatment. Furthermore, the highest economic returns (1053.3 and 1050.5 $ ha⁻¹) and benefit:cost ratio were observed under 90 kg P₂O₅ ha⁻¹ + seed inoculation with PSB during both years. In conclusion, application of 90 kg P₂O₅ ha⁻¹ combined with PSB seed inoculation is a pragmatic option to improve P uptake, grain yield, PUE, grain quality and economic returns of pearl millet grown on calcareous soils.

Keywords:

• Cost:benefit ratio
• millet growth
• phosphorus-deficiency
• seed inoculation
• sustainable approach

Acknowledgments

The authors express their sincere gratitude to the Plant Nutrition Laboratory, Department of Soil Science, Bahauddin Zakariya University, Multan, for their invaluable assistance in conducting soil and grain analysis.

Author contributions

Conceptualization, Mubshar Hussain; Formal analysis, Abdul Majeed; Investigation, Abdul Majeed and Muhammad Bahram Khan; Methodology, Abdul Majeed, Muhammad Bahram Khan and Ahmad Dawood; Project administration, Mubshar Hussain; Supervision, Mubshar Hussain; Validation, Sajid Masood and Muhammad Naveed; Writing – review & editing, Mubshar Hussain, Abdul Majeed, Sajid Masood, Muhammad Naveed. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

The authors declare no conflict of interest.

Data availability statement

All relevant data are within the manuscript.