Phosphorus nutrition of oats genotypes in acidic soils: Exploiting responsive plant-microbe partnership

Abstract

Genotype-microbes interactions in rhizosphere can be a promising approach to improve P nutrition of crop plants in acidic soils. This study explored the response of contrasting oat genotypes to the conjunctive application of microbial consortia and differently soluble phosphatic fertilizers. Effect of microbial consortia [vesicular arbuscular mycorrhiza (VAM), Azotobacter chroococum, Aspergillus niger, and Pseudomonas sp.] with tri‑calcium phosphate or potassium di‑hydrogen phosphate on the P nutrition of oat genotypes (Kent and JHO-851) was evaluated in controlled condition. Microbial consortia alone or in conjunction with 50% recommended dose of P fertilizers significantly increased the forage yield and P uptake. Kent was more responsive compared with JHO- 851 to consortia and P fertilization. Plant P content in Kent genotypes showed strong correlation with microbial biomass carbon (MBC), nitrogen (MBN), acid and alkaline phosphatases activities, Bray’s P and actinobacteria population in soils. Forage yield and P uptake response was similar with tri‑calcium phosphate and potassium di‑hydrogen phosphate. Root biomass, MBN and Bray’s P contributed for 90% variability in P uptake. Results advocated that responsive oat genotype and microbial consortia with 50% recommended P fertilizers dose or tricalcium phosphate can be a low-cost option for efficient P nutrition in acidic soils.