The Combinatorial Optimization And Fertilizer Efficency Of The Oiltea Camellia Rhizobacterial Strains

Camellia oleifera is an important woody oil plant in China. Because of the long growth periods of Camellia, it is necessary to maintain the soil fertility for the purpose of sustainable and high yield. The microbial fertilizer, which is friendly to the ecological environment, can improve soil physical and chemical properties, regulate plants growth and increase the yield. Promotion and application of microbial fertilizer is an important measure to upgrade Camellia oleifera production in China.In this study, we analyzed the ecological distribution of camellia rhizosphere nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-releasing bacteria and screened high-efficiency strains; meanwhile combined and optimized fermentation condition of the selected ones, analyzed the fertilizer efficiency and micro-ecological effects of the bacterial manure as well. The results as follow:(1) Ecological distribution and selection of the functional bacterial strain from camellia rhizosphere. We analyzed the distribution of nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-dissoluting bacteria from rhizosphere and non-rhizosphere of camellia, the results showed that the potassium-releasing bacteria (R/S=9.4)> phosphate-solubilizing bacteria (R/S=2.75)> nitrogen-fixing bacteria (R/S=1.75). we separated and screened the former three kind of strains from the rhizosphere of Camellia, the results of activity test showed that the strain N11 has the strongest activity(39.09 mg/kg) among the 36 nitrogen-fixing strains, and the strain N19 (37.19 mg/kg) was secondary in activity; the strain P1 has the strongest activity (9.56 mg/kg) among the 15 phosphate-solubilizing strains; the strain K50 with activity (121.71 mg/kg) was the strongest among the 73 potassium-dissoluting strains, and strain K56 comes second with the activity (106.54mg/kg).(2) Combination and optimization of these functional strains. There are no antagonistic reactions among the functional strains by streak cultivation and liquid mixed culture. Combined the 5strains functional bacteria and test the activity, we found that N11+P1+K50+K56 was a set of flora combination with higher nitrogen fixation, phosphorus dissolving and potassium releasing activity. On the base of Ashby culture medium, we took the cane sugar 8g, glucose 10g, ammonium nitrates 0.25g, NaCl 0.3g to replace carbon, nitrogen source and NaCl and cultured with inoculum concentration 6%, medium volume 50mL (250mL flask), temperature 30℃,140 r/min and pH7.5 to obtain the stronger nitrogen fixation activity;on the base of Pikovaskaia's culture medium, we took the sugar 12g, ammonium nitrates 0.5g, yeast powder 0.4g, NaCl 0.2g to replace the carbon, nitrogen source and NaCl, and cultured with inoculum concentration 4%, medium volume 50mL (250mL flask), temperature 30℃,140 r/min and pH7.0 to obtain the stronger phosphorus dissolving activity; on the base of the potassium bacteria releasing medium, we took the glucose 8g, mannitols5g, ammonium nitrates 1.5g, beef extract 0.5g to replace the carbon and nitrogen source, and cultured with inoculum concentration 4%, medium volume 50mL (250mL flask), temperature 35℃,160 r/min, and pH7.5 to obtain the higher potassium releasing activity.(3) Study on development and effects of compound bacterial manure. The method of how we develop compound bacterial fertilizer is to mix the fermentation broth (1:1:1), which was fermented under optimal fermentation condition of each functional strain, was adsorbed with 1:10 adsorption proportion by the carrier which was the mixture of the bentonite and peat that sterilized in 150mins. Different ratio of compound bacterial manure and chemical fertilizer affect the growth of Camellia differently, we fertilized the camellia with the proportion that bacterial manure 40% and chemical fertilizer 60%, then the results showed that:the height of seedling increased 45.4%, stem base raise up 19,1%, and the quality of new root increased 27.4%. By using compound bacterial manure, the increment of rhizosphere microorganisms was 49.73%; the soil organic matter increased 10.53%, the nitrogen availability in soil increased 8.68%, the phosphorus availability raised up 13.29% and the increment of potassium availability in soil was 11.56%.