Phosphate-Solubilizing Bacteria Nullify the Antagonistic Effect of Soil Calcification on Bioavailability of Phosphorus in Alkaline Soils

Amanullah Amanullah,Muhammad Arshad,Shah Saud,Hafiz Mohkum Hammad,Wajid Nasim,Zahir Shah,Inayat-Ur Rahman,Mukhtar Alam,Shah Fahad,Muhammad Zahid Ihsan,Yousaf Jamal,Muhammad Adnan,Ishaq Ahmad Mian,Imtiaz Ali Khan,Muhamamd Arif,Hidayat Ullah,Abdul Basir

doi:10.1038/s41598-017-16537-5

Abstract

Phosphate-solubilizing bacteria (PSB) reduce the negative effects of soil calcification on soil phosphorus (P) nutrition. In this incubation study, we explored the ability of PSB (control and inoculated) to release P from different P sources [single super phosphate (SSP), rock phosphate (RP), poultry manure (PM) and farm yard manure (FYM)] with various soil lime contents (4.78, 10, 15 and 20%) in alkaline soil. PSB inoculation progressively enriched Olsen extractable P from all sources compared to the control over the course of 56 days; however, this increase was greater from organic sources (PM and FYM) than from mineral P sources (SSP and RP). Lime addition to the soil decreased bioavailable P, but this effect was largely neutralized by PSB inoculation. PSB were the most viable in soil inoculated with PSB and amended with organic sources, while lime addition decreased PSB survival. Our findings imply that PSB inoculation can counteract the antagonistic effect of soil calcification on bioavailable P when it is applied using both mineral and organic sources, although organic sources support this process more efficiently than do mineral P sources. Therefore, PSB inoculation combined with organic manure application is one of the best options for improving soil P nutrition.

Highlights

Phosphate-solubilizing bacteria (PSB) reduce the negative effects of soil calcification on soil phosphorus (P) nutrition
We explored the ability of phosphate solubilizing bacteria (PSB) to release P from different P sources [single super phosphate (SSP), rock phosphate (RP), poultry manure (PM) and farm yard manure (FYM)] with various soil lime contents (4.78, 10, 15 and 20%) in alkaline soil
PSB inoculation progressively enriched Olsen extractable P from all sources compared to the control over the course of 56 days; this increase was greater from organic sources (PM and FYM) than from mineral P sources (SSP and RP)

Summary

Introduction

Phosphate-solubilizing bacteria (PSB) reduce the negative effects of soil calcification on soil phosphorus (P) nutrition. PSB have been reported to modify P nutrition and increase its solubalization in soil through many process such as, they may decrease the pH of the soil by the producing organic (gluconic acid) and mineral acids[14], alkaline phosphatases[15], phytohormones and H+ protonation[16], anion exchange, chelation and siderophores production which promote P solubilization in soil[17]. Exploitation of these processes may prevent frequent addition of P into soil with a substantial reduction in cost of production to the farmers and damage to the environment[18]. The use of PSB promote the growth of plant in other way such as by speeding up seed germination, improving seedling emergence, increasing resistance to abiotic stress, guard plants from disease and improving root morphology[20]

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