Effect of submergence on rhizospheric soil enzyme activity and fertility of bermudagrass (Cynodon dactylon)

Bermudagrass that naturally grows in water fluctuation (XC) and non-water fluctuation (FC) zones in the Three Gorges Reservoir Area was submerged in different depths of water in order to investigate rhizospheric soil enzyme activities and fertility under different submergence stresses. The results showed that sucrase activity in non-flooded rhizospheric soil was higher than those in soils submerged with different depths of water, suggesting the flooded soils were not as rich in plant nutrients as non-flooded soils. The activities of urase and acid phosphatase in FC rhizospheric soil were higher than those in XC rhizospheric soil. FC rhizospheric soil N content was significantly lower than that of XC after flooding. Total phosphorus in FC rhizospheric soil was significantly higher than that in XC before flooding. This suggested that XC used more soil nutrients than FC during growth period and reserved more energy which enhanced its submergence-resistant ability. All these findings indicated that there existed some relationships among rhizospheric soil enzyme activity, fertility and tolerance to submergence in bermudagrass under different habitats (submergence stress).