and the pellets suspended in 0.85% NaCl (OD600 = 1.0). The bacterial suspensions were separately mixed with sterilized activated charcoal (4:6 v/w) to give a CFU of approximately 107/g
of charcoal-based bacterial inoculants. Plant growth under controlled environment Seeds of Zea mays var. Girija surface sterilized with 20% sodium hypochlorite for 3 min. and washed thrice with sterile distilled water were germinated at 25°C in moist sterile vermiculite. Uniformly germinated seeds were coated with the selleck compound water slurry of charcoal-based microbial inoculants (approx. 5 × 105 CFU/seed) and two seeds per pot sown in 15 cm diameter pots filled with 2 kg non-sterilized sandy-loam soil. The soil used had pH 6.96, organic matter 3.1%, available N 0.03%, available P 0.0011%, available K 0.013% and available Ca 0.028%. The germinated seeds treated with the water slurry of sterilized check details activated charcoal without inoculum were used for the control treatments. N and K were applied in the form of ammonium sulfate @ 240 kg N/ha, and muriate of potash @ 80 kg K/ha, respectively. P was applied @ 120 kg P/ha either as single super phosphate (SSP) or tricalcium phosphate (TCP) according to the various treatments. The phosphate-solubilizing bacterial (PSB) treatments included one P. fluorescens strain, three P. poae strains, ten P. trivialis strains, and five Pseudomonas spp. strains in combined application
with NPK with TCP as the phosphate source. TCP was chosen as phosphate substrate since P-deficiency in soils of the cold deserts of Lahaul and Spiti is attributed mainly to the presence of insoluble di- and tricalcium phosphates. The influence of PSB treatments on plant growth and soil properties was evaluated in comparison to the uninoculated control treatments with or without TCP and SSP. The pots were placed in a complete randomized block design with four replications under 550 μM photon m-2
s-1 mixed incandescent and fluorescent illumination, 16/8 h light/dark cycle and 50–60% RH at 25 ± 2°C in an Environment Control Chamber. The plants were removed carefully under a gentle flow of tap water after 90 days of sowing. Data on root length, plant height (aerial parts), root dry weight Janus kinase (JAK) and shoot dry weight were recorded. The samples were oven-dried at 70°C for 3 days to a constant weight for determining the dry weight. Chemical analyses The soil samples were air dried and sieved for determining pH, available N, P, K, Ca and organic matter content. The plant samples were oven-dried and powdered for estimation of total N, P and K. Organic matter was Bucladesine in vivo determined by the modified Walkley and Black method [12]. Estimation of total N was done by modified Kjeldahl’s method, total P by vanado-molybdate yellow colour method, total and available K by flame photometric method, and available Ca in ammonium-acetate extracts [13].
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