Effects Of Microbial Fertilizers On The Growth Of Rice And Soil Environment In Saline-alkali Land

Because of the high groundwater level,drought,less rain and strong evaporation,secondary salinization was caused,and the unreasonable management methods of agriculture for a long time resulted in soil salinization.Soil salinization endangers plant tissues,causes physiological drought,retards nutrient uptake,affects stomatal opening and closing,destroys photosynthesis and restricts agricultural comprehensive productivity.The improvement of saline-alkali land by biological measures is a research hotspot at present,and also a trend of innovative research in the future.In this study,three salt-tolerant strains were selected from saline-alkali soil:Halobacillus dabanensis,Halomonas Meridiana and Bacillus subtilis.The salt tolerance and alkaline tolerance tests were used to analyze the maximum salt and alkaline tolerance of the strains.The results showed that Halobacillus dabanensis grew normally in the LB medium with NaCl content of 120 g/L and pH=12;Halomonas Meridiana grew normally in the LB medium with NaCl content of 120 g/L and pH=12;Bacillus subtilis grew normally in the LB medium with NaCl content of 150 g/L and pH=13.The optimum environmental conditions of the three strains were determined by orthogonal test.The results showed that the optimum conditions were 15%inoculation,30"C and pH=9.The maximum number of bacteria was 3.47×108 CFU/g.Three strains of bacteria were added to the bio-organic fertilizer manufactured in the laboratory,and pot and field experiments were carried out according to different treatments.The effects of microbial fertilizers on Agronomic Characteristics and chemical properties of saline-alkali soils at seedling stage,tillering stage,heading stage and maturity stage of rice were studied.The results showed that there were significant differences in SPAD value,plant height,leaf area,ear length,number of effective ears,1000-grain weight and CK;The actual output was 648.10kg/667m2,an increase of 11.83%.Soil total phosphorus,organic matter and alkali-hydrolyzed nitrogen were significantly different from the control group,increasing by 22.47%,17.45%and 21.11%respectively;the number of bacteria,actinomycetes and fiungi compared with CK.The results showed that bio-organic fertilizer could improve Rice Agronomic characteristics,soil nutrients and soil microbial biomass.The microbial fertilizer has a good effect on the improvement of saline-alkali land,and has a good application potential.