Effect Of Different Sand/Soil Ratio On The Recovery Ability Of Hybrid Burmudagrass After Trampling

The hybrid bermudagrass T-419 was established on the turf -bed consisting of different ratio of Nanjing Yangtze River washed coarse or fine sand and the local garden soil. The sand accounts for the proportion of the total volume was 25%,50%,75%,100%, respectively in the turf-bed. The hybrid bermudagrass T-419 turf was heavily trampled by turf trampler from June 1,2010 to June 24,2010, and it was recovered from June 25,2010 to July 25,2010. The soil bulk density and soil total porosity, some growth indexes including leaf length, height, height growth rate, green leaves rate, pruning biomass, biomass above-ground and biomass under-ground of bermudagrass T-419, as well as turf density, coverage, texture and colour of bermudagrass were investigate from June 1,2010 to July 25,2010. The purpose of this study was to select the optimum sand/soil ratio for the recovery growth of bermudagrass trampled heavy,and to probe the mechanism of the optimum sand/soil ratio. The results have great significance to provide technical support and theoretical basis in order to establish and manage hybrid bermudagrass T-419 turf scientifically. The results are as follows.Whether coarse sand treatment or fine sand treatment, the soil perviousness was improved with increasing sand content after trampling. The soil total porosity of the treatments with 75%,100% coarse sand and with 50%,75%,100% fine sand was more than 40%, which was beneficial to the growth of turf grass. The soil bulk density and porosity of the treatments with 25% fine sand and with 100% soil varied significantly, and their turf bed was seriously compacted whether before or after trampling,.In regard to growth indexes, the leaf lengths of different treatment did not increase significantly with increasing sand content, but the height growth rate and the biomass above-ground of the coarse sand treatment showed the trend of increase, and the fine sand treatment decreased after initial increasing. Whether coarse sand treatment or fine sand treatment, the green leaves rate showed the trend of decrease after initial increasing, and the biomass under-ground and pruning amount increased with increasing sand content.The turf density decreased after initial increasing with increasing sand content during the whole recovery period. The turf densities of the treatments with 50% and with 75% sand content were lower than other treatments at different sample times. After the turf was trampled 20 days later, the turf coverage of the treatments of all four coarse sand and with 75%,100% fine sand was return to the level before trampling and there is no difference before and after trampling. The leaf widths showed difference only at the tenth day of the recovery period, the leaf width of the treatment of 75% coarse sand was narrowest and best turf texture, but the turf texture of the of all soil treatment was worst. The content of chlorophyll of different treatments had no significant difference before trampling, but they decreasing after trampling gradually. The contents of chlorophyll of the treatments 75%, 100% coarse sand and 100% soil after trampling 20 days later were no significant difference with before trampling, but the contents of chlorophyll of other treatments were significantly lower than that before trampling.The recovery capability of the treatments with 75%,100% coarse sand and with 75% fine sand showed better after heavy trampling. The treatment of 100% coarse sand should be primarily considered to the sports turf with heavy trampling, but it needs much more water and fertilizer so that the cost will also be increased. It is a good choice to use the turf bed with 75% sand content if the sports turf was trampled lightly or for recreation turf because the cost was lower than that of the treatment of 100%.