草本植物生长发育对土壤团聚体稳定性影响的试验研究

The Effect of Herbaceous Plant Growth on the Soil Aggregate Stability

为了研究草本植物生长发育对土壤团聚体稳定性的影响,利用盆栽试验和Le Bissonnais法中的慢速湿润法研究了不同植被生长发育对土壤团聚体平均重量直径(MWD)的影响。试验设计包括4种盆栽方式处理(冰草、高羊茅、紫花苜蓿和空白对照),设计的试验天数分别为90 d、130 d、220 d和250 d。研究结果表明,三种草被的地上生物量和地下生物量皆随植被生长时间的增加而显著增加。在250 d的盆栽试验条件下,空白对照的土壤团聚体MWD基本无变化,而冰草和紫花苜蓿处理下的MWD在250 d生长期呈显著的增加趋势,高羊茅处理的MWD与空白对照处理相同。相关分析表明,草被生长时间、地上生物量、地下生物量和土壤有机质与团聚体MWD均为正相关,而除冰草的生长时间和地下生物量与土壤团聚体MWD呈显著相关外,其他各因素与MWD相关性均没达到显著水平,同时说明在本试验条件下,草被生长时间和植被种类是影响土壤团聚体稳定性的重要因素。

The effect of the growth of wheatgrass（Agropyron cristatum）,tall fescue（Festuca arundinacea） and alfalfa（Medicago sativa） on the soil aggregate stability was investigated in a greenhouse using the pot experiment and slow wet method of Le Bissonnais method.The experimental design includes four treatments（wheatgrass,tall fescue,alfalfa and blank control）,and the scheming experiment days are 90 d,130 d,220 d and 250 d,respectively.The results showed that the aboveground biomass and underground biomass of three plants increased significantly with growth.Under the experiment treatments,the mean weight diameter（MWD） of soil aggregate for control treatment was not changed during 250 d of experiment.For the wheatgrass and alfalfa treatments,MWD increased significantly during 250 d of experiment,while for the tall fescue treatment,change trend of MWD was similar to the control treatment.The correlation analysis showed that the grass growth time,aboveground biomass,underground biomass and soil organic matter have the positive effects on MWD.For wheatgrass treatment,there was significant correlation between MWD,growth time and underground biomass,while for tall fescue and alfalfa treatments,there was no significant correlation.Meanwhile,under the experimental conditions,the growth time and plant species of grass were the major factors affecting soil aggregate stability.