Co-Inoculation with Phosphate-Solubilizing Microorganisms of Rock Phosphate and Phosphogypsum and Their Effect on Growth Promotion and Nutrient Uptake by Ryegrass

Abstract

In the previous half-century, natural rock phosphates (PN) have been a valuable alternative for phosphorus (P) fertilizer for sustainable agriculture; furthermore, phosphogypsum (PG) has been widely used as a soil amendment fertilizer since it improves some soil properties, increases crop yields, and represents an environmental concern that can make a good economic profit; this research aimed to study the effects of microbial consortia of phosphate-solubilizing microorganisms (PSM) on the solubilization of PN and PG in the soil, and their effects on promoting plant growth and nutrient assimilation using ryegrass as a plant model. Local supply of PG with Pseudomonas fluorescens (MW165744) significantly increases root proliferation and plant biomass dry weight compared to other isolates, as well as improves total P uptake, with a maximum value of 62.31 mg/pot. The opposite occurred in mixing inoculation with Pseudomonas fluorescens, Pantoea agglomerans (MW165752) and Stenotrophomonas maltophilia (MW221274), with a negligible total P assimilation of 5.39 mg/pot. Whereas the addition of Pseudomonas agglomerans with PG gave outstanding total P absorption of 57.05 mg/pot when compared with PN input of 38.06 mg/pot. Finally, the results prove that the co-inoculation of Pseudomonas fluorescens with PG could be a promising and alternative option to use it as a source of P fertilizer for plants and to maintain a high level of nutrients in the soil.

Effects of Apatite Concentrate in Combination with Phosphate-Solubilizing Microorganisms on the Yield of Ryegrass Cultivar Izorskiy

“…The greatest increase in the P removal from the biologized fertilizer and its conversion into a form available for plants was observed for V5 treated with the apatite concentrate of standard grinding in combination with strains BI2, BI14, and BS89 (4 × 10 6 CFU/g each) and for V8 treated with the apatite concentrate of fine grinding in combination with strains BI14 and BS89 (6 × 10 6 CFU/g each). This result is in accordance with the previous study [19] of the effects on ryegrass of co-inoculation Pseudomonas fluorescens (MW165744) with apatite, which represented the significant increase of total P uptake. It can be assumed that analogous results of these two experiments reflect the similarity of experimental methods for analyzing the growth of Lolium multiflorum in sterilized soil conditions.…”

“…However, the best performance was observed for V5 (13.09%), which appeared to have optimal parameters in terms of the grinding degree and combination and amount of PSMs. Our results on PUE, which was calculated considering the direct effect of P on ryegrass, are consistent with those obtained in one-and two-year field experiments at Rothamsted (UK), where the average P recovery calculated by a different method was 5-10% [19,24].…”

Isolation of Phosphate-Solubilizing Microorganisms and the Formulation of Biofertilizer for Sustainable Processing of Phosphate Rock

“…PSMs are known to promote plant growth. The study of Amri et al [ 47 ] showed results related to this. The results of our study were also consistent with this observation.…”

The utilization of microbes for sustainable food production

“…These organic acids help reduce soil pH and may act as chelators for divalent cations such as calcium, releasing bonded phosphorus iron for plant absorption (Saxena et al, 2019 ). For instance, Amri et al ( 2022 ) found that using Pseudomonas fluorescens as a P-fertilizer on ryegrass increased root proliferation and plant biomass. This approach is promising and could serve as an alternative source of P-fertilizers to maintain high nutrient levels in crops such as maize, wheat, and rice (de Abreu et al, 2017 ; Li et al, 2021 ).…”