Submitted to: Canadian Journal of Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/18/2013
Publication Date: 1/24/2013
Citation: Hu, X., Roberts, D.P., Xie, L., Maul, J.E., Yu, C., Li, Y., Zhang, S., Liao, X. 2013. Development of a biologically based fertilizer, incorporating Bacillus megaterium A6, for improved phosphorus nutrition of oilseed rape. Canadian Journal of Microbiology. 59:231-236. Interpretive Summary: Sustainable methods for the production of oilseed rape need to be developed. Use of chemical fertilizers for the production of oilseed rape and other crops can introduce damaging levels of phosphate into the environment. A potential solution is to develop phosphate-solubilizing microorganisms that help provide adequate quantities of phosphorus to plants in combination with reduced quantities of chemical fertilizer. In this study we show that the beneficial bacterium Bacillus megaterium A6, when applied in waste oilseed rape meal, significantly improves oilseed rape yield and soil available phosphorus compared to the nontreated control. We also show that this bacterium is capable of solubilizing mineral phosphate and organic phosphate in liquid culture and when grown on the waste oilseed rape meal. Finally, we demonstrate that this bacterium, applied with the waste oilseed rape meal and chemical fertilizer, reduced in phosphate content, provides substantially improved oilseed rape yield. These experiments identify this bacterium as an excellent candidate for development to be used in alternative strategies for fertility management of oilseed rape and other crops. This information will be useful to scientists.
Technical Abstract: Sustainable methods with diminished impact on the environment need to be developed for the production of oilseed rape in China and other regions of the world. A biological fertilizer consisting of Bacillus megaterium A6 cultured on oilseed rape meal doubled oilseed rape seed yield (P < 0.0001) relative to the nontreated control in two greenhouse pot experiments using natural soil. Strain A6 was capable of solubilizing phosphorus from rock phosphate in liquid culture and produced enzymes capable of mineralizing organic phosphorus (acid phosphatase, phytase) in liquid culture and in the biological fertilizer. The biologically based fertilizer, containing strain A6, improved plant phosphorus nutrition in greenhouse pot experiments resulting in significantly greater available phosphorus in natural soil and in significantly greater plant phosphorus content relative to the nontreated control and the autoclaved biological fertilizer treatments. Seed yield and available phosphorus in natural soil were significantly greater with a synthetic chemical fertilizer treatment, reduced in phosphorus content, than the biological fertilizer treatment but a treatment containing the biological fertilizer combined with the synthetic fertilizer provided the significantly greatest seed yield, available phosphorus in natural soil, and plant phosphorus content. These results indicate that the biological fertilizer improved oilseed rape seed yield, at least in part, through the phosphorus solubilizing activity of B. megaterium A6 resulting in improved plant phosphorus nutrition. These results also indicate that the biological fertilizer treatment is compatible with synthetic chemical fertilizer treatments.