高羊茅根土复合体水力分离研究  

Hydraulic separation of the root-soil complex in Festuca arundinacea

作　　者：程洪[1] 江辉[1] 张路 赵建民[1] 詹新武[1] CHENG Hong;JIANG Hui;ZHANG Lu;ZHAO Jianmin;ZHAN Xinwu(National and Local Joint Engineering Laboratory for Water Engineering Safety and Efficient Utilization of Resources in Poyang Lake Basin/School of Water Resources and Ecology,Nanchang Institute of Technology,Nanchang 330099,Jiangxi,China;Institute of Soil and Water Conservation,Ministry of Water Resources,Chinese Academy of Sciences,Yangling 712100,Shaanxi,China)

机构地区：[1]鄱阳湖流域水工程安全与资源高效利用国家地方联合工程实验室/南昌工程学院水利与生态学院,江西南昌330099 [2]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《草业科学》2022年第11期2350-2360,共11页Pratacultural Science

基　　金：江西省教育厅科学技术研究项目(GJJ180925);国家自然科学基金资助项目(51869012);江西省重点研发项目(20201BBG71002);江西省水利厅水利科技项目(202022TGKT08)。

摘　　要：为揭示根土物质之间的复杂关系,明晰植物根系提高土壤颗粒粘聚力和阻抗或延缓因水力侵蚀而使土壤颗粒分离的双重作用机制,本研究选择广泛应用于水土保持的高羊茅(Festuca arundinacea)为代表性植物,播种于红壤、高岭土和河沙3种生长基质内,对根土复合体进行物理化学测定、水力冲刷和抗剪强度试验。结果表明:1)根系因子中的根长密度、根表面积密度、根体积密度极显著正相关(P<0.05)。2)不同深度的土壤抗冲性有较大差异,0-2 cm土层深度的抗冲性远远大于其他土层,抗冲性能大小排序为表层>次底层>次表层>底层。3)每30 cm^(2)土壤播种量为60粒的根土复合体粘聚力高于30粒播种量,且其土壤抗冲性也是最强的。4)根土复合体提高了土壤分离的耗时与冲刷水量或能量消耗,薄层水流作用的第2分钟显著延长了剥蚀时长和耗时(P<0.05),显著增加了冲刷水量(P<0.05),极显著增加了能量消耗(P<0.01)。研究结果为根系固土降低土壤分离机制地研究提供了新的科学参考依据。To reveal the complex relationship between roots and soil materials,it is necessary to clarify the dual mechanism of plant roots that increase the soil shear strength,or delay the separation of soil particles because of water erosion.Festuca arundinacea,which is widely used in soil and water conservation,was selected as a representative plant,and it was sown in three growth substrates:red soil,kaolin,and river sand.Through physical and chemical determination of the root-soil complex,hydraulic scour and shear strength tests showed that:1)Root length density,surface area density,and volume density in root system factors were positively correlated with each other in an extremely significant manner,and significantly positively correlated with the growth of organic matter in the complex.2)The erosion resistance of soil at different depths was extremely different.The erosion resistance of the 0–2 cm soil layer was far greater than that of other soil layers.The order of erosion resistance was:surface layer>sub-bottom layer>subsurface layer>bottom layer.3)The cohesion of the root-soil complex with 60 seeds per 30 cm^(2) was higher than that with 30 seeds,and its soil anti-scouring index was also the strongest.4)The formation of the root-soil complex improved the time-consuming process of soil separation and the amount of scouring water or energy consumption.Within the second minute of action of the thin water flow,the length and time of denudation were prolonged(significantly positive correlation),and the amount of washed water or energy consumption was increased(significantly negative correlation or extremely significant).The results of this study provide a new scientific reference for the study of root consolidation mechanisms to reduce soil separation.

关 键 词：高羊茅 粘聚力 土壤分离 水力侵蚀 根土复合体 抗剪强度 

分 类 号：S688.4[农业科学—观赏园艺]