[en] The phosphate-solubilizing bacteria (PSB) can solubilize insoluble forms of phosphorous (P) into simple soluble forms that can be taken up by plants. The main focus of this study was to determine the effect of PSB on P availability in presence of different P rates for improved and sustainable rice (Oryza sativa L.) production under aerobic conditions. Triple superphosphate (TSP) at three levels (0, 30 and 60 kg ha–1) and two isolated PSB (Bacillus sp.) strains (PSB9 and PSB16) were tested in glasshouse conditions. Surface sterilized seeds of aerobic rice (M9 variety) were planted in plastic pots containing 3 kg of soil for 60 days. PSB strains exhibited capability of producing organic acids from soil and plant roots and increased yield of aerobic rice. Significantly, high P solubilization (28.7 mg kg–1) and plant uptake (7.94 mg kg–1) was found in PSB16 inoculated treatments at 30 kg ha–1 of P2O5. In this treatment were also observed high leaf chlorophyll content (34.57), photosynthesis rate (7.59 μmol CO2 m–2 s–1) and root development. Isolated strains showed potential to make higher availability of P and increase content of organic acids from soil and roots at lower doses of TSP in aerobic rice. With the production of organic acids (oxalic, malic, succinic and propionic) higher amounts of P in the soil solution increased plant P uptake and resulted in higher plant biomass. The application of these potential inoculants in an appropriate combination with chemical fertilizers could be considered in organic and sustainable aerobic rice cultivation system.

[es] Las bacterias solubilizadoras de fosfato (PSB) son capaces de solubilizar formas insolubles de f&oacute;sforo (P), para que puedan ser absorbidas por las plantas. Se estudi&oacute; el potencial de dos cepas de PSB (Bacillus sp.), PSB9 y PSB16, para la solubilizaci&oacute;n del P y el aumento del crecimiento del arroz aer&oacute;bico (Oryza sativa L.) en condiciones de invernadero, utilizando superfosfato triple (TSP) a tres niveles (0, 30 y 60 kg ha&ndash;1). Se sembraron semillas de arroz aer&oacute;bico (variedad M9) en macetas de pl&aacute;stico con 3 kg de suelo. Las cepas PSB fueron capaces de producir &aacute;cidos org&aacute;nicos a partir del suelo y de las ra&iacute;ces de las plantas y aumentaron el rendimiento del arroz aer&oacute;bico. Se encontr&oacute; una alta y significativa solubilizaci&oacute;n de P (28,7 mg kg&ndash;1) y de absorci&oacute;n por la planta (7,94 mg kg&ndash;1) en los tratamientos inoculados con PSB16 utilizando 30 kg ha&ndash;1 de P2O5. En este tratamiento tambi&eacute;n se observ&oacute; un alto contenido de clorofila (34,57), tasa de fotos&iacute;ntesis (7,59 mmol CO2 m&ndash;2 s&ndash;1) y desarrollo de ra&iacute;ces. Las cepas mostraron potencial para una mayor disponibilidad de P y aumento de &aacute;cidos org&aacute;nicos del suelo y las ra&iacute;ces a bajas dosis de TSP en el arroz aer&oacute;bico. Con la producci&oacute;n de &aacute;cidos org&aacute;nicos (ox&aacute;lico, m&aacute;lico, succ&iacute;nico y propi&oacute;nico), mayores cantidades de P solubles en el suelo incrementaron la captaci&oacute;n de P por la planta y como resultado, aument&oacute; su biomasa. Estos potenciales inoculantes combinados adecuadamente con fertilizantes qu&iacute;micos pueden ser aplicados en un cultivo org&aacute;nico y sostenible del arroz aer&oacute;bico.