黄土丘陵区冻融对土壤抗冲性及相关物理性质的影响

ISWC OpenIR > 水保所知识产出(1956---)

	黄土丘陵区冻融对土壤抗冲性及相关物理性质的影响
其他题名	Effect of seasonal freeze-thaw on soil anti-scouribility and its related
	李强; 刘国彬; 许明祥; 孙会; 张正; 高丽倩
	2013
发表期刊	农业工程学报
卷号	29 期号:17 页码:105-08
摘要	在股状水流侵蚀比较发育的黄土丘陵区,土壤可蚀性主要依赖于土壤抗冲能力。为了揭示季节性冻融对土壤抗冲性的影响,该文借助模拟冲刷试验,设置了裸地对照(CK)、黑麦草传统密度(LD)和加倍密度(HD)3种处理,测定并分析了冻融前后土壤物理性质及其抗冲性。结果表明,与冻融前相比,表层土壤容重、团聚体含量和根系密度在3个处理中均未发生显著变化(P<0.05),土壤黏聚力略有下降,而崩解速率在处理CK、LD和HD中分别增加了20.6%、18.8%和7.3%。冻融作用延后了3个处理的主要产沙时间,降低了土壤抗冲能力,增加了冲刷中途泥沙流失速率。与未冻融相比,冻融作用增加了处理CK和LD泥沙流失量为19.41%和6.70%,但对处理HD影响较小(P<0.05)。冻融和根系共同作用在LD和HD处理上分别减少土壤流失量为3.72%和49.39%。该研究期望对完善土壤侵蚀机理提供一定的参考价值。
其他摘要	Seasonal freeze-thaw plays a significant role in soil properties as well as the management of soil and water resources in northern latitudes. Soil erodibility primarily relies on soil anti-scouribility (AS) in the concentrated flow erosion zones of the Loess Plateau. An understanding of the characteristics of freeze-thaw soil is essential for erosion essence in the seasonal freeze-thaw area. The primary goal of this study was to evaluate the differences in soil AS and its related freeze-thaw-induced soil physical properties, as well as root density before and after a cycle of freeze-thaw. For this purpose, a simulated scouring experiment was conducted on a loam soil with sand content 23.0%, silt content 65.2% and clay content 11.8%. Three treatments considered were: 1) fallow (CK), 2) low density (LD) and 3) high density (HD) of ryegrass. Each treatment had four replicates. Rectangular, undisturbed soil samples (20 cm × 10 cm × 10 cm) were installed in the fallow and root pans and were fitted with a hydrological flume (2 m × 0.10 m). The flume contained an opening at its lower base equal to the size of metal sampling box, so that the soil surface of soil sample was at the same level as the flume surface. The space between the sample box and the flume edge was sealed with painter’ mastic to prevent edge effect. The slope of the flume bottom could be varied. Clear tap water flow was applied at 4.0 L/min rate discharge on a washing flume slope of 15° for 15 min. During the 15 minutes of each experiment, samples of runoff and detached soil were collected every 1 min in the first 3 min and every 2 min subsequently using 10 L buckets for determining sedimentation. Soil physical properties determined were soil bulk density (g/cm3), water–stable aggregate content (%), cohesion C, and disintegration rate (cm3/min). Root biomass was obtained by the harvest method and dried in an oven. The first samples were taken on October 26, 2012, and last ones were taken on March 23, 2013. The results indicated that no significant changes were found in soil bulk density, water-stable aggregate content, and root density after a cycle of freeze-thaw compared with those before freeze-thaw. Comparatively, soil cohesion decreased slightly, whereas soil disintegration rate increased by 20.6%, 18.8%, and 7.3% in treatments CK, LD, and HD respectively as compared with those before freeze-thaw. In addition, freeze-thaw delayed the occurrence of main sediment production, reducing soil AS, as well as increasing both the rate of sediment loss in the middle scouring time and the total sediment yield. Among the treatments, compared with those before freeze-thaw, the freeze-thaw increased sediment by 19.41% and 6.70% in treatments CK and LD, but there was little effect in HD. The combined effect of root biomass and freeze-thaw in sediment reduction was 3.72% and 49.39% in the LD and HD treatments, respectively. The findings may provide a supplement for understanding the erosion mechanisms and provide guidance for management strategies dealing with seasonal freeze-thaw areas.
关键词	土壤侵蚀物理性质冻融作用土壤抗冲性根系黄土丘陵区
语种	中文
文献类型	期刊论文
条目标识符	sbir.nwafu.edu.cn/handle/361005/5515
专题	水保所知识产出(1956---)
推荐引用方式 GB/T 7714	李强,刘国彬,许明祥,等. 黄土丘陵区冻融对土壤抗冲性及相关物理性质的影响[J]. 农业工程学报,2013,29(17):105-08.
APA	李强,刘国彬,许明祥,孙会,张正,&高丽倩.(2013).黄土丘陵区冻融对土壤抗冲性及相关物理性质的影响.农业工程学报,29(17),105-08.
MLA	李强,et al."黄土丘陵区冻融对土壤抗冲性及相关物理性质的影响".农业工程学报 29.17(2013):105-08.

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