Compost biofortification with diazotrophic and P-solubilizing bacteria improves maturation process and P availability

Area of Science:

• Agricultural Microbiology
• Soil Science
• Biotechnology

Background:

• Tropical agriculture faces challenges due to low plant-available phosphorus (P) in soils.
• Conventional phosphorus fertilizer production from rock phosphate (RP) is costly, limiting access for smallholder farmers.
• Biotechnological approaches offer a sustainable alternative for enhancing P availability from RP.

Purpose of the Study:

• To evaluate the impact of co-inoculating Burkholderia silvatlantica and Herbaspirillum seropedicae on rock phosphate (RP)-enriched compost.
• To determine the effects of these microorganisms on phosphatase activities and the release of plant-available P.
• To assess the potential of this co-inoculation strategy as a biotechnological tool for sustainable agriculture.

Main Methods:

• Composting of rock phosphate (RP) enriched with organic matter.
• Co-inoculation of Burkholderia silvatlantica and Herbaspirillum seropedicae into the compost.
• Measurement of phosphatase activities (acid and alkaline).
• Quantification of plant-available P fractions (water-soluble P, citric acid P).

Main Results:

• Co-inoculation significantly increased organic matter decomposition and humic acid formation during composting.
• Herbaspirillum seropedicae demonstrated high potential for producing acid and alkaline phosphatase enzymes.
• Both inoculated microorganisms enhanced the release of plant-available P, indicated by increased water-soluble P and citric acid P levels.

Conclusions:

• The co-inoculation of Burkholderia silvatlantica and Herbaspirillum seropedicae in RP-enriched compost is an effective biotechnological strategy.
• This approach can accelerate composting processes and improve phosphorus (P) supply from recalcitrant sources.
• This method offers a cost-effective and sustainable solution for enhancing P availability in tropical agricultural systems.