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Perovskite LaFeO3 is one of the most useful materials for the application in a catalyst, gas sensors, and fuel cells, etc. LaFeO3 nanoparticles were synthesized by the citrate sol-gel method. According to the TG-DTA analysis on LaFeO3 xerogel powder, the proper crystallization temperature was found to be at 450 °C. The TEM images also show clear crystal formation was started at 450 °C. The LaFeO3 nanocrystalline particles were obtained by sintering the calcined powders at different temperatures (800 °C, 900 °C, and 1000 °C) for 4 hours. The resulting particles were characterized by XRD, EDXRF, FT IR, and SEM analysis. At 900 °C, the XRD pattern of LaFeO3 shows an orthorhombic crystal structure. The average crystallite sizes vary between 30-60 nm and the increase in crystallite size with increasing sintering temperatures and it may be due to the increase in grain growth. FT IR analysis shows strong La-O and Fe-O vibrations. Based on the XRD and FT IR data, the optimum sintering temperature was chosen at 900 °C. The SEM micrographs show that the morphology of LaFeO3 has small-sized grains with round shape. The optical properties were determined by UV-visible spectroscopy in the wavelength range of 300 nm-700 nm. The optical band gap energy values of LaFeO3 using Tauc’s plot were found to be about 2.45 eV. These results indicate that the LaFeO3 prepared by the sol-gel method has a relatively lower band gap value and so it can have the potential for photocatalytic applications.

Mineral oil, peanut oil and soybean oil were compared with water and gum arabic for their suitability as adhesives for seed inoculation with peat inoculants. Inoculated seeds were stored at 4, 28 and 34°C, and sampled after 1, 3 and 9 days to determine the survival of rhizobia. Germination and nodulation tests were performed on the inoculated seeds. Results showed that oils were suitable adhesives for peat inoculants. Although the oils initially bound less inoculant to the seed, the number of surviving rhizobia was similar to that obtained by the gum arabic treatment after storage at 28 and 34°C for 3 and 9 days. An interesting finding of this experiment was that peanut and soybean oils were superior to gum arabic in supporting significantly higher numbers of chickpea rhizobia at 34°C. Inoculated seeds tested for germination and nodulation showed no adverse effects from the oil treatments. Oils hold good potential as adhesives for seed application in inoculation technology.

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In this study, 13 bacteria were isolated from the agricultural soils of Kyaukse city, Myanmar, and out of these isolates, two bacteria isolates viz. JU-24 and JU-33 are found to be potent phosphate (P) solubilisers and are selected for further studies. These two isolates are identified as Bacillus megaterium based on the 16S rRNA gene sequence. When the growth rates of these two isolates were tested for salt tolerance, they could grow well in media with NaCl concentrations of 3%, 6% and 9%. For 0% and 3% NaCl concentrations, JU-33 (84.37 mg/L for 0% NaCl and 130.36 mg/L for 3% NaCl) showed higher P-solubilising efficiency than JU-24 (73.29 mg/L for 0% NaCl and 87.42 mg/L for 3% NaCl) for both NaCl concentrations when inoculated in Ca3(PO4)2 containing liquid medium. In media containing AlPO4 and FePO4 without NaCl, the P-solubilising activity of JU-24 is higher than JU-33 for these two substrates. Moreover, these strains showed noticeable levels of P solubilisation activity in the presence of various carbon sources indicating high P-solubilising efficacy. The soil inoculation experiment revealed that inoculating the experimental soil with JU-33 resulted in an obvious increase in available P, which increased from 13.08 mg/L in the non-inoculated soil to 18.40 mg/L in the inoculated soil with the bacterial isolate, JU-33. This study clearly showed that JU-24 and JU-33 isolates could be used as biofertilizers in ecological agricultural systems and may help to sustain environmental health and soil productivity. The use of biofertilizers can reduce the use of expensive chemical fertilisers, reducing planting costs and improving soil fertility through long-term use. Biofertilizers can help solve the problem of feeding an increasing global population at a time when agriculture is facing various environmental stresses and are affordable for low-income farmers.

Phosphate solubilizing Bacillus megaterium was isolated from non rhizospheric soils. Five isolates were identified by 16s rDNA sequencing. According to sequencing and phylogenetic tree analysis, these five isolates were in high similarity with B. megaterium. Abiotic stresses such as temperature, pH and salt tolerance of five strains were examined for the application for abiotic stressed agricultural soils. All five strains could grow well above 40ºC. For pH, five strains demonstrated their growth on minimal media at pH 9 but the growth rates were decreased. Among abiotic stress factors, to obtain salt tolerance phosphate solubilizing B. megaterium was the main objective of this research work. So, salt tolerance of isolates were screened preliminary, all five strains had the ability to grow on minimal media containing 6% NaCl concentration but the growth rates were not in high rates. Preliminary screening results enhanced to continue for quantative determination of phosphate solubilization under salt stressed conditions. In detection of phosphate solubilization by the method of Olsen P, all five strains could solubilize insoluble phosphate, Tricalcium phosphate, under NaCl stressed conditions. Among 4%, 5% and 6% NaCl concentrations, soluble phosphate concentrations released by five strains were decreased with increasing NaCl concentrations, but it was not obviously different.