Ditching Phosphatic Fertilizers for Phosphate-Solubilizing Biofertilizers: A Step towards Sustainable Agriculture and Environmental Health

Abstract

Chemical phosphatic fertilizers are mainly produced from phosphate rocks, a natural reserve that is depleting rapidly. These chemical phosphatic fertilizers are polluting the environment at an alarming rate as a result of injudicious application to farmlands. On the other hand, phosphate-solubilizing biofertilizers (PSBs) are often considered better alternatives to industrial phosphatic fertilizers in many ways. PSBs are microorganisms capable of solubilizing insoluble forms of phosphate into soluble plant-usable forms. This paper is written with the objective of discussing the impacts of phosphatic fertilizers and making the case for why we should shift to PSBs instead. Phosphatic fertilizers have numerous impacts on the environment (water bodies, land resources, and air), and micro- and macro-organisms, including humans. Chemical fertilizers also tend to be more expensive, especially for farmers in developing countries. On the contrary, PSBs tend to be safer and way more beneficial than their chemical counterparts in that they are environmentally friendly and cheaper options of availing plant-usable phosphorus. PSBs are also involved in other beneficial roles such as the production of phytohormones and secretion of anti-phytopathogenic metabolites. The phytohormones enhance plant growth and the metabolites render crops immunity against phytopathogens. Hence, it is vital to replace chemical phosphatic fertilizers with PSB inoculants both to prevent the irreversible impacts of chemical fertilizers and to take advantage of the numerous benefits of PSBs. Moreover, it does not seem as if there is an option given the fact that the global phosphate reserve is depleting and the impact of fertilizer on the environment is worsening as time goes by.

Exploring Endophytic Bacteria from Artemisia spp. and Beneficial Traits on Pea Plants

“…Based on Pikovskaya [ 47 ] methods further created by Gupta et al [ 48 ] which are widely applied as an evaluation tool [ 49 ], we assessed the potential of the isolates to solubilize phosphate on Pikovskaya’s agar medium (PVK). The PVK solid medium contains blue bromophenol, which produces halos around the colonies due to organic acid production.…”

Isolation, Identification, and Characterization of Phosphate-Solubilizing Bacteria from Tunisian Soils

“…The bacteria isolates were tested for their ability to solubilize phosphate according to the methods of Nautiyal [ 21 ] and Pikovskaya [ 22 ] using the NBRIP and PVK media. An improved Pikovskaya’s phosphate growth (PVK) solid medium containing blue bromophenol, which produced yellow-colored halos around the colonies due to organic acid production, was developed by Gupta et al [ 23 ], and is commonly used in the screening of PSB [ 9 ]. Nautiyal [ 21 ] developed the National Botanical Research Institute’s phosphate growth liquid medium (NBRIP) comprising glucose, 5.0 g/L of tricalcium phosphate (TCP), magnesium chloride hexahydrate, magnesium sulfate heptahydrate, potassium chloride ammonium sulfate, and distilled water, and this medium is widely used for the evaluation of phosphate solubilization [ 9 , 24 ].…”

“…Solubilization of mineral phosphates is an important ability exhibited by some microorganisms, motivating the study of their solubilizing capability [ 9 ]. The phosphate-solubilizing bacteria (PSB) are predominant over other phosphorus-solubilizing microorganisms and play an important role in biogeochemical phosphorus cycling in both terrestrial and aquatic environments [ 10 ].…”

Soil Fungi in Sustainable Agriculture

“…Fungi can also promote plant tolerance to various environmental stresses, such as heavy metals, salinity, and drought. They help plants adapt to these harsh conditions by providing nutrients, improving water uptake, and regulating stress hormones [ 16 ]. In the third contribution , the authors describe the whole process of production of plant-available P by soil microorganisms, which is extremely complex with a wide number of abiotic and biotic factors characterizing each different soil or site.…”