Effect Of Inoculation With Native Phosphate Solubilizing Microorganisms On The Available Phosphorus Content In The Rhizosphere And Uptake Of Phosphorus By Rice Plants, Grown In An Indian Alluvial Soil

Abstract

Summary Three efficient phosphate solubilizing microorganisms, isolated from an alluvial soil (Fluvaquent), ACB 6 — Bacillus firmus (B - 7651), ACS 6 - Streptomyces sp. and ACF 2 — Aspergillus Candidus , were used to inoculate in rock phosphate (BP), farmyard manure (FYM), FYM + KP, rice straw (RS), and RS + RP to study their effect on the available phosphorus content of the rhizosphere soils, uptake of phosphorus by and dry weight of rice ( Oryza sativa L., cv. IR-8) plants at early tillering and preflowering stages of growth in a pot culture experiment with the same soil. In an average, available phosphorus content of the rhizosphere soils of IR-8 rice increased significantly with the application of RS and with a combined inoculation of ACB 6 + ACS 6 + ACF 2 · So happened for the uptake of phosphorus by plants with FYM and with a combined inoculation of ACB 6 + ACS 6 and for dry weight of the plants with FYM and with a combined inoculation of ACS 6 + ACF 2 . Accumulation of available phosphorus in the rhizosphere, uptake of phosphorus by the plants and dry weight of the plants were found highest with the inoculation of ACB 6 with RS; ACB 6 + ACS 6 + ACF 2 with RS + RP and with ACB 6 + ACS 6 with RP, respectively, at early tillering stage and with the inoculation of ACB 6 + ACS 6 with RS; ACB 6 + ACS 6 with FYM; and ACF 2 with FYM + RP, respectively, at preflowering stage of growth. Thus a combined inoculation of the native phosphate solubilizing isolates, either two or three taken together coupled with the judicial application of FYM and RS in presence and absence of RP would be beneficial for the rice crop.