不同坪床配比对‘阳江’狗牙根草坪耐践踏性的影响

采用大田实验,研究了连续两年模拟践踏处理对不同坪床配比[河沙(S)∶黄沙(C)=0∶100、20∶80、40∶60、60∶40、80∶20、100∶0(对照)]的国审品种‘阳江’狗牙根运动场草坪坪床物理性质、根系形态、根系空间分布、草坪生长和坪用质量的影响。结果表明,践踏处理增加了土壤容重、土壤紧实度和土壤剪切力,降低了土壤总孔隙度;坪床物理性质的变化虽然降低了‘阳江’狗牙根草坪地下部生长,但是改变了根系形态,促进了根系向深层扩展;根系形态和分布的变化影响了草坪地上部生长和坪用质量,草屑、残茬干重和坪用质量降低而地上部密度增加。与传统的纯河沙坪床比较,混入一定比例的黄沙,降低了土壤紧实度,促进了根系生长和向根系层深处的扩展,提高了草坪地上部密度和残茬干重,增加了草皮的耐磨损性,全面提高了运动草坪的耐践踏性。其中,践踏处理对坪床配比河沙60%黄沙40%的坪床物理性质、根系形态和分布、地上部生长和坪用质量的影响最小。因此,河沙60%黄沙40%为‘阳江’狗牙根最佳坪床配比。

Effect of different turf-bed soil ratios on the traffic resistance of ‘Yangjiang’ bermudagrass sports turf

The effects of simulated trampling on turf physical characteristics and quality, turfgrass growth, root morphology, root spatial distribution, were measured for two consecutive years in a field experiment, using the nationally registered Bermudagrass variety ‘Yangjiang’ with different turf bed ratios [river sand∶yellow sand] of 0∶100, 20∶80, 40∶60, 60∶40, 80∶20, 100∶0 (control). It was found that simulated trampling increased soil bulk density, soil compaction and soil shear strength, and decreased soil total porosity. The compaction-related changes in physical properties of the experimental turf-beds caused a change in root morphology reflected in deeper expansion of the root system, but reduced above-ground growth of ‘Yangjiang’ Bermudagrass, including decreased dry weight of clippings and verdure, a decline in turf quality score, but increased above-ground density of turf. Compared with a pure river sand turf-bed, inclusion of yellow-sand in the turf-bed decreased soil compaction, promoted root growth and rooting depth, increased turf density, dry weight of turf clippings and turf verdure, and enhanced the traffic resistance of the turf. The beneficial effects of including yellow sand in the turf-bed were optimized with a 60%∶40% ratio of river sand∶yellow sand. Therefore, 60% river sand and 40% yellow-sand is the recommended optimum ratio for construction of turf-beds.