农业工程学报
農業工程學報
농업공정학보
2013年
17期
105-112
,共8页
李强%刘国彬%许明祥%孙会%张正%高丽倩
李彊%劉國彬%許明祥%孫會%張正%高麗倩
리강%류국빈%허명상%손회%장정%고려천
土壤%侵蚀%物理性质%冻融作用%土壤抗冲性%根系%黄土丘陵区
土壤%侵蝕%物理性質%凍融作用%土壤抗遲性%根繫%黃土丘陵區
토양%침식%물이성질%동융작용%토양항충성%근계%황토구릉구
soils%erosion%physical properties%seasonal freeze-thaw%root%soil anti-scouribility%hilly Loess Plateau
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。
在股狀水流侵蝕比較髮育的黃土丘陵區,土壤可蝕性主要依賴于土壤抗遲能力。為瞭揭示季節性凍融對土壤抗遲性的影響,該文藉助模擬遲刷試驗,設置瞭裸地對照(CK)、黑麥草傳統密度(LD)和加倍密度(HD)3種處理,測定併分析瞭凍融前後土壤物理性質及其抗遲性。結果錶明,與凍融前相比,錶層土壤容重、糰聚體含量和根繫密度在3箇處理中均未髮生顯著變化(P<0.05),土壤黏聚力略有下降,而崩解速率在處理CK、LD和HD中分彆增加瞭20.6%、18.8%和7.3%。凍融作用延後瞭3箇處理的主要產沙時間,降低瞭土壤抗遲能力,增加瞭遲刷中途泥沙流失速率。與未凍融相比,凍融作用增加瞭處理CK和LD泥沙流失量為19.41%和6.70%,但對處理 HD 影響較小(P<0.05)。凍融和根繫共同作用在 LD 和 HD 處理上分彆減少土壤流失量為3.72%和49.39%。該研究期望對完善土壤侵蝕機理提供一定的參攷價值。
재고상수류침식비교발육적황토구릉구,토양가식성주요의뢰우토양항충능력。위료게시계절성동융대토양항충성적영향,해문차조모의충쇄시험,설치료라지대조(CK)、흑맥초전통밀도(LD)화가배밀도(HD)3충처리,측정병분석료동융전후토양물이성질급기항충성。결과표명,여동융전상비,표층토양용중、단취체함량화근계밀도재3개처리중균미발생현저변화(P<0.05),토양점취력략유하강,이붕해속솔재처리CK、LD화HD중분별증가료20.6%、18.8%화7.3%。동융작용연후료3개처리적주요산사시간,강저료토양항충능력,증가료충쇄중도니사류실속솔。여미동융상비,동융작용증가료처리CK화LD니사류실량위19.41%화6.70%,단대처리 HD 영향교소(P<0.05)。동융화근계공동작용재 LD 화 HD 처리상분별감소토양류실량위3.72%화49.39%。해연구기망대완선토양침식궤리제공일정적삼고개치。
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. <br> 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.