Coupling Phosphate-Solubilizing Bacteria with Phosphorus Supplements Improve Maize Phosphorus Acquisition and Growth under Lime Induced Salinity Stress.

Martin Brtnicky,Subhan Danish,Raja Mohib Muazzam Naz,Shah Saud,Jiri Holatko,Muhammad Zafar-Ul-Hye,Imran Ahmad,Rahul Datta,Martin Leonardo Battaglia,Shah Fahad,Beena Saeed,Muhammad Adnan,Zhen Yue,Shahen Shah,Ishaq Ahmad Mian,Muhammad Zamin

doi:10.3390/plants9070900

Abstract

Global warming promotes soil calcification and salinization processes. As a result, soil phosphorus (P) is becoming deficient in arid and semiarid areas throughout the world. In this pot study, we evaluated the potential of phosphate-solubilizing bacteria (PSB) for enhancing the growth and P uptake in maize under varying levels of lime (4.8%, 10%, 15% and 20%) and additional P supplements (farmyard manure, poultry manure, single super phosphate and rock phosphate) added at the rate of 45 mg P2O5 kg−1. Inoculation and application of P as organic manures (Poultry and farm yard manures) improved maize growth and P uptake compared to the control and soils with P applied from mineral sources. Liming adversely affected crop growth, but the use of PSB and organic manure significantly neutralized this harmful effect. Mineral P sources combined with PSB were as effective as the organic sources alone. Furthermore, while single supper phosphate showed better results than Rock phosphate, the latter performed comparably upon PSB inoculation. Thus, PSB plus P application as organic manures is an eco-friendly option to improve crop growth and P nutrition in a calcareous soil under changing climate.

Highlights

Climate is one of the vital factors influencing soil-forming processes and properties
Except for GR, the other growth attributes were significantly affected by phosphate-solubilizing bacteria (PSB) inoculation (Table 4)
Seed inoculation with PSB was beneficial regardless of the source of P, the use of the bacteria was more crucial when P was supplemented from mineral sources, especially as Rock phosphate (RP)

Summary

Introduction

Climate is one of the vital factors influencing soil-forming processes and properties. The global climate has been constantly changing throughout geological earth history, the extent to which current changes occur at a human life scale is dramatic. The global average temperature is estimated to increase by another 2–3 ◦ C by the end of 21st century [1]. The impact of these changes on soil is not predictably directional, resulting in changes that may vary in strength, occurrence (i.e., permanent or periodical) and outcome (i.e., favorable or unfavorable effects). CO2 concentration, temperature, drought stress, uneven precipitation and atmospheric N2 deposition have significant negative impact on soil functions [2]. There is evidence that crop yields have significantly decreased due to increased salinization and calcification with increasing aridity under changing climate [3]

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Results

Discussion

Conclusion