摘要
【目的】土壤抗剪强度和抗冲性是反映土壤综合对抗水力侵蚀性能和评价复合农林业模式生态效益的指标。研究植物篱模式对土壤抗剪强度、抗冲性及其坡面分布的影响,为探讨植物篱模式控制水土流失及农业非点源污染机理研究提供参考。【方法】利用植物篱控制水土流失的长期定位试验,采用原位监测法测定土壤抗剪强度,原状土冲刷法测定土壤抗冲性,剖面挖掘法测定根系参数,简易比重计法、湿筛法、吸管法、环刀法等测定土壤颗粒组成、水稳性团聚体组成、微团聚体组成、容重等主要土壤理化性质,数理统计方法研究紫色土区植物篱模式对坡耕地土壤抗剪强度、抗冲性及其坡面分布的影响。【结果】与横坡农作模式相比,0—10 cm和10—20 cm土层土壤在20°坡地紫穗槐模式下的平均抗剪强度(SS)分别增加70.3%和89.3%,平均抗冲指数(ASI)分别增加84.1%和35.2%;香根草模式下,平均SS分别增加49.6%和133%,平均ASI分别增加48.0%和26.1%;13°坡地紫花苜蓿模式下,平均SS分别增加62.2%和51.9%,平均ASI分别增加188%和57.3%;蓑草模式下,平均SS分别增加89.7%和50.6%,平均ASI分别增加175%和26.9%。20°坡地植物篱模式提高土壤SS与ASI的平均效应分别为85.5%和48.4%,13°坡地的分别为63.6%和112%。土壤ASI随冲刷时间增长呈幂函数型增大,植物篱模式土壤抗冲性的增幅远大于横坡农作模式。坡面自下而上,横坡农作模式土壤抗剪强度与抗冲性呈近直线式减小或自下、中坡位急剧减小;植物篱模式的呈波浪式减小,篱带增加,作物带减小。【结论】植物篱模式明显或显著提高了土壤抗剪强度与抗冲性。就表层(0—10 cm土层)土壤而言,20°坡地紫穗槐模式提高土壤抗剪强度与抗冲性的效应大于香根草模式;13°坡地紫花苜蓿模式提高土壤抗剪强度的效应小于蓑草模式,提高土壤抗冲性效应大于蓑草模式。20°坡地植物篱模式提高土壤抗剪强度效应大于13°坡地,提高土壤抗冲性效应则小于13°坡地。植物篱模式改善了坡地土壤抗剪强度与抗冲性的过大坡面异质性。
【Objective】Soil shear strength （SS） and anti-scouring （AS） are indexes that reflect comprehensive ability of soil confronting water erosion and evaluate ecological benefits of agro-forestry model. To provide reference for the mechanism research of hedgerow patterns controlling soil and water loss and agricultural non-point pollution, the effects of hedgerow patterns on soil SS and AS and their slope distribution were studied. 【Method】Based on a long-term experiment on the effect of hedgerows controlling soil and water loss, the effects of hedgerow patterns on soil SS and AS and their slope distribution were discussed on slope farmland in purple soil area of central Sichuan. Research methods involved in situ monitoring for determination of soil SS, undisturbed-soil trough scouring for determination of soil AS, soil profile excavation for determination of root parameters, simple hydrometer method , wet sieve analysis, cutting ring method and so on for determinations of soil main physico-chemical properties, and mathematical statistics for analysis of soil SS and anti-scouribility index （ASI） among treatments. 【Result】Compared with conventional contour farming pattern, in 20° slope farmland, the mean SS of 0-10 cm and 10-20 cm soil layers under amorpha pattern increased by 70.3% and 89.3% , respectively; the mean ASI of 0-10 cm and 10-20 cm soil layers under amorpha pattern increased by 84.1% and 35.2%, respectively; the mean SS of 0-10 cm and 10-20 cm soil layers under vetiver pattern increased by 49.6% and 133%, respectively; the mean ASI of 0-10 cm and 10-20 cm soil layers under vetiver pattern increased by 48.0% and 26.1%, respectively. In 13° slope farmland, the mean SS of 0-10 cm and 10-20 cm soil layers under alfalfa pattern increased by 62.2% and 51.9%, respectively; the mean ASI of 0-10 cm and 10-20 cm soil layers under alfalfa pattern increased by 188% and 57.3%, respectively. The mean SS of 0-10 cm and 10-20 cm soil layer under Eulaliopsis pattern increased by 89.7% and 50.6%, respectively; the mean ASI of 0-10cm and 10-20 cm soil layers under Eulaliopsis pattern increased by 175% and 26.9%, respectively. The average increment of soil SS and ASI under hedgerow patterns in 20° slope was 85.5% and 48.4%, respectively; that in 13° slope increased by 63.6% and 112%, respectively. Soil ASI increased by power function with increasing of scouring time. However, the added value of soil ASI with increasing of scouring time for hedgerows was higher than conventional contour farming pattern. From low to top slope, soil SS and ASI of conventional contour farming pattern decreased by nearly line or sharply in low or middle slope; those of hedgerow patterns decreased by wave, and they increased in hedgerow belt and decreased in crop belt. 【Conclusion】Hedgerow patterns enhanced obviously soil SS and AS. In terms of surface soil （0-10 cm soil layer）, in 20° slope farmland, the effect of amorpha pattern on improvement of soil SS and AS was higher than those of vetiver; in 13° slope farmland, the effect of alfalfa on improvement of soil SS was lower than that of Eulaliopsis binat, however the effect of alfalfa pattern on improvement of soil ASI was higher than that of Eulaliopsis binat. The effect of hedgerow patterns on improvement of soil SS in 20° slope farmland was higher than that of 13° slope. The effect of hedgerow patters on improvement of soil AS in 20° slope farmland was lower than that of 13° slope farmaland. Hedgerow patterns improved excessive slope heterogeneity of soil SS and AS.
出处
《中国农业科学》
CAS
CSCD
北大核心
2014年第5期934-945,共12页
Scientia Agricultura Sinica
基金
国家自然科学基金(41371301)
国家水体污染控制与治理科技重大专项课题(2012ZX07104-003)
重庆市工程技术研究中心建设项目(CSTC
2010CB7008)
关键词
植物篱模式
抗剪强度
抗冲性
坡耕地
坡面分布
hedgerow patters
shear strength
anti-scouribility
slope farmland
slope distribution
