Inoculation of phosphate-solubilizing bacteria improves soil phosphorus mobilization and maize productivity

Abstract

Phosphate-solubilizing bacteria represent a bioalternative in making soil-immobilized phosphorus (P) available to plants, and consequently improve agriculture sustainability and reduce nutrient pollution. In this study, we examined whether Rhizobium sp. B02 inoculation can affect the soil P fractions. Moreover, we investigated how inoculation influences the growth, physiological traits, and productivity of the maize crop. Field tests were carried out to evaluate the combined application of strain B02 and reduced doses of P fertilizer. Soil P fractionation was performed after crop harvesting, assessing the P dynamics. To study the plant response, samplings were carried out in three phenological stages—the vegetative stage of the 7 fully emerged leaves with leaf collars (V7), the vegetative stage of the tassel (VT), and the reproductive stage of physiological maturity (R6). Using 50% of P fertilizer recommended, the strain inoculation increased the labile inorganic P fraction by 14% compared to the control treatment at the same dose, indicating that it favored the Pi mobility. Under these same conditions in the V7 and VT phenological stages, the inoculation significantly improved shoot length (28 and 3%) and shoot dry weight (9.8 and 12%). B02 inoculation increased grain yield by 696 kg ha−1 using 50% of the recommended rate of P fertilizer, phenocopying the complete P fertilization treatment without inoculation. Therefore, Rhizobium sp. B02 inoculation replaced 50% of P fertilizer in maize and increased the soil P availability.

Phosphate-Solubilizing Bacteria with Low-Solubility Fertilizer Improve Soil P Availability and Yield of Kikuyu Grass

“…In response to this problem, this study demonstrated the potential of PSB inoculation with different P sources to improve soil P lability, thus transforming insoluble forms of P into usable forms for Kikuyu grass, and in turn reducing the application of synthetic fertilizers. Preliminary studies have shown that PSB inoculants improve soil P dynamics and promote soil P legacy circularity [ 25 , 26 , 38 ].…”

“…These results coincided with the higher acid phosphomonoesterase activity ( Figure 5 ) and the higher availability of P and P in the labile fraction of the soil. Beltran et al [ 38 ] found a greater availability of P in the labile fractions with the inoculation of Rhizobium sp., improving growth and development in annual forage crops and P nutrition, in turn allowing a reduction in the application of mineral P fertilizers to 50%. The synergism between PSB inoculation and low-solubility P sources increased dry matter accumulation in Kikuyu grass relative to high-solubility mineral sources.…”

Assessing the Effects of Land-use and Slope Aspects on Soil Phosphorus Fractions: a Comparative Study in Degraded and Naturally Regenerated Forest Ecosystems

“…ECM fungi can mobilize P, in uence host plant growth and P uptake [45], [46], and provide nutrients for Przewalski horses in the Hustai area. On the other hand, phosphate-solubilizing bacteria able to improve soil phosphorus mobilization increasing labile Pi [47].…”

Effect of Mineral Fertilization and Microbial Inoculation on Cabbage Yield and Nutrition: A Field Experiment

“…Also, the capacity of some microbes to release soluble P from insoluble forms can positively affect plant growth. Inoculation of Rhizobium in non-leguminous plants, for example, resulted in an increased transformation of P from unavailable to available forms in soil, thereby enhancing plant nutrition [10]. Co-inoculation of strains possessing multiple PGP traits, therefore, has the potential to improve nutrient utilization.…”