Effects Of Silicon Fertilizer On Wear Tolerance Of Kentucky Bluegrass(Poa Pratensis L.)

Effects of spraying silicon fertilizer(non-silicon,low,moderate and high) on the anatomical structures,cell wall components and chlorophyll content of Kentucky bluegrass were studied.Then, we carried out a certain degree of wear on the lawn to observe membrane damage and the change of antioxidant enzymes activities(SOD,POD,CAT).Effects and regulation mechanism of silicon on wear resistance of Kentucky bluegrass were discussed through anatomical structures and physiological metabolism,in order to provide a good theoretical and practical foundation for improving wear resistance of turfgrass.1. The thickness of stratum corneum of lower epidermis of Kentucky bluegrass increased after using high-silicon fertilizer. The average thickness of the midrib and leaf margin was about1.16μm. The coverage of stratum corneum increased.The number of sclerenchyma of leaf increased up to ten, significantly higher than the control treatment. Vascular bundles showed symmetric distribution,with the midrib as the centre.Large vascular bundle and small vascular bundle are alternatively arranged.19vascular bundles in the leaf was observed which includes9large vascular bundles and10small vascular bundles.Silicon fertilizer treatment had no effect on the number of vascular bundle.2.The content of cellulose and acid detergent lignin of Kentucky bluegrass showed an upward trend after spraying silicon fertilizer. The content of cellulose and acid detergent lignin of moderate and high-silicon treatment group was significantly higher than the control group after thirty days.The content of cellulose and acid detergent lignin of low-silicon treatment had no significant difference with the control.3.Chlorophyll content of each treatment rose to different degree after using silicon fertilizer. The content rising rate increased after thirty days of fertiliazation. Chlorophyll content of moderate and high-silicon treatment was significantly higher than the control.Applying appropriate amount of silicon fertilizer had positive effects on chlorophyll content and photosynthetic performance.Theoretically, it can promote the recovery of Kentucky bluegrass after wear and enhance its wear resistance.4.The content of H2O2of Kentucky bluegrass of different treatments after wear increased firstly and reduced later.reaching a peak at two hours after wear.Half an hour after wear,the content of H2O2of silicon treatments were significantly lower than that of the control.One and two hours after wear, the content of H2O2of high-silicon treatment was the lowest and showed significant difference with the control. Four and eight hours after wear, the content of H2O2of moderate and high-silicon treatments were significantly lower than that of the control.lt shows that high concentration of silicon fertilizer can reduce the accumulation of H2O2after wear and help remove active oxygen.5. High concentration of silicon fertilizer can reduced the conductivity and malondialdehyde content of Kentucky bluegrass significantly after wear. It shows that high concentration of silicon fertilizer can protect membrane system and decrease membrane lipid peroxidation.6.The activity of SOD,POD and CAT of each silicon treatment of Kentucky bluegrass increased firstly and reduced later,but their peaks occured at different times.The activity of SOD of each treatment reached the maximum value on the fifth day of wear.The activity of SOD of high-silicon treatment was significantly higher than that of the control on the fifth and fifteen day of wear, increasing by16.5%and12.1%, respectively.The activity of POD of each treatment reached the maximum value on the tenth day of wear. The activity of POD of high-silicon treatment was significantly higher than that of the control on the fifth day of wear. The activity of POD at other time points did not show significant difference.The activity of CAT of silicon treatment group reached the maximum value on the fifth day of wear, five days earlier than the control group. The activity of POD of middle-silicon treatment was significantly higher than that of the control on the fifth day of wear, increasing by about26.1%. The activity of POD of low-silicon and middle-silicon treatment had significant difference on the fifteenth day of wear, increasing by24.7%and40.1%, respectively. It shows that a appropriate amount of silicon fertilizer can enhance the activity of antioxidant enzymes of Kentucky bluegrass after wear, contributing to the removal of reactive oxygen species after injury. It can improve resisting oxidative damage ability and recovery ability of turfgrass after wear.