Microbial Phosphorus Solubilization and Its Potential for Use in Sustainable Agriculture

Abstract

The use of excess conventional Phosphorus (P) fertilizers to improve agricultural productivity, in order to meet constantly increasing global food demand, potentially causes surface and ground water pollution, waterway eutrophication, soil fertility depletion, and accumulation of toxic elements such as high concentration of selenium (Se), arsenic (As) in the soil. Quite a number of soil microorganisms are capable of solubilizing/mineralizing insoluble soil phosphate to release soluble P and making it available to plants. These microorganisms improve the growth and yield of a wide variety of crops. Thus, inoculating seeds/crops/soil with Phosphate Solubilizing Microorganisms (PSM) is a promising strategy to improve world food production without causing any environmental hazard. Despite their great significance in soil fertility improvement, phosphorus-solubilizing microorganisms have yet to replace conventional chemical fertilizers in commercial agriculture. A better understanding of recent developments in PSM functional diversity, colonizing ability, mode of actions and judicious application should facilitate their use as reliable components of sustainable agricultural systems. In this review, we discussed various soil microorganisms that have the ability to solubilize phosphorus and hence have the potential to be used as bio fertilizers. The mechanisms of inorganic phosphate solubilization by PSM and the mechanisms of organic phosphorus mineralization are highlighted together with some factors that determine the success of this technology. Finally we provide some indications that the use of PSM will promote sustainable agriculture and conclude that this technology is ready for commercial exploitation in various regions worldwide.

Ectomycorrhizal fungi and soil enzymes exhibit contrasting patterns along elevation gradients in southern Patagonia

“…Mortierellaceae richness and abundance were also positively correlated with PHOS. Mortierellaceae putatively perform rock weathering, thereby mobilizing essential lithophilic plant nutrients, particularly P (Alori et al, 2017). P uptake involving ECM fungi has been demonstrated (Landeweert et al, 2001;K€ ohler et al, 2018), but the contribution of Mortierellaceae to P availability in the rhizosphere is unknown.…”

Sustainable Agriculture—Enhancing Environmental Benefits, Food Nutritional Quality and Building Crop Resilience to Abiotic and Biotic Stresses

“…The ability to solubilize P from compounds in soil is fairly wide-spread amongst soil microbes and certain biological control agents have been shown to control disease and solubilize P [85]. All three Bacillus isolates, B. subtilis Tu-100, B. subtilis BY-2, and B. megaterium A6 solubilized phosphate from inorganic and organic sources (Hu et al,unpublished;[86].…”

“…In addition to controlling disease, combinations of all three isolates in treatments of oilseed rape seeds resulted in promotion of growth relative to the nontreated control in five different soils (Hu et al, unpublished) indicating that these plant-beneficial microbes contribute multiple environmental benefits. As with biological control, environmental conditions influence the ability of these microbes to solubilize P [85]. More research is needed regarding colonization and mode of action of these plant-beneficial microbes to facilitate their use in enhancing sustainability of crop production systems.…”

Plant Nutrient Dynamics in Stressful Environments

“…In contrast, phytic acid (PA), the organic form of P in seeds, has increased following global changes (e.g., elevated atmospheric CO 2 ) in various plant species including wheat [84]. Since PA is considered an anti-nutrient, increasing Pi content in grain while decreasing PA has become a trait of great interest [85].…”

“…Agriculture 2017, 7,85 Author Contributions: All the authors assisted in the development of the research and in the discussion of the results.…”