西南山区等高植物篱和植物固结地埂的水土保持功能的理解

水土流失是个世界范围的严重环境问题,比如由于丰沛的降雨和陡坡耕作,造成的中国西南部偏僻山区的坡耕地水土流失.这些区域采取了多种保持土壤措施减少土壤流失,可当地农民并不接受引进的等高植物篱措施;而植物固结地埂是一项传统的且当地农民乐意接受的水土保持措施.本文比较了等高植物篱和植物固结地埂的结构,设置3种植物固结地埂高度0 (CK)、10cm (H10H)、和15 cm (H15H),分析了等高植物篱(H0H)和上述3种地埂高度的植物固结地埂对径流、侵蚀量的影响及产投比和经济效益,旨在理解当地农民的选择.研究结果显示最明显的区别是植物固结地埂具有一定高度的地埂能够方便农事活动并且有效减少水土流失.植物固结地埂的第2个处理(H15H)比无地埂无植物篱的坡耕地处理(CK)减少径流55.56％±6.25％,减少侵蚀量79.26％±3.50％.不同处理的径流量、土壤侵蚀减少量和土壤抗蚀性变化顺序为:H15H＞H10H＞H0H＞CK.H15H的产投比最高为1.52.与其他试验处理相比,虽然H15H措施需要的劳动力更多,但它具有较高的植物篱收获量和产投比以及较强的抗冲蚀性.因此,西南地区坡耕地上推荐具有15 cm地埂高度的植物固结地埂措施(H15H),甚至该项水土保持措施可适用于与西南地区气候相似的其它区域或是其它国家.

Understanding the effects of contour hedgerow and terracing hedgerow on soil and water conservation in the remote mountainous regions of Southwest China

Background] Soil and water loss is a serious worldwide environmental problem,for example,soil loss from the sloping cultivated lands in the remote mountainous regions of Southwest China due to the abundant precipitation and steep sloping cultivated lands in these areas.Various soil protection techniques have been adopted to prevent soil loess,the local people did not admire the introduced contour hedgerow measurement from abroad;however,they have been actively accepted another traditional one,the terracing hedgerow.The purpose of this work is to understand the differences on soil and water conservation between contour hedgerow and terracing hedgerow.Methods] The different structure between four treatments of contour hedgerow and terracing hedgerow were analysed.Meanwhile,three heights (0 cm,10 cm,and 15 cm) of lynchet were set,and the soil erosion module,runoff efficiency,ratio of output and input,economic effects among the different treatments were compared.The soil antiscourability was calculated using the equation,and analysis of variance (ANOVA) was performed with SPSS 11.5 and Microsoft Excel software.Results] The obvious difference was that terracing hedgerow with a certain height of walkway was more convenient for farming activities and effectively reduced soil and water loss.The treatment of terracing hedgerow 2 (H15H) reduced runoff 55.56％ ± 6.25％ and reduced erosion modulus 79.26％ ± 3.50％ when compared to the sloping cultivated land plots with no lynchet and no hedgerow (CK).The contributions of the independent variables on runoff,soil erosion reduction and soil anti-scouring were in the following order:terracing hedgerow 2 (H15H) ＞ terracing hedgerow 1 (H10H) ＞ contour hedgerow (HOH) ＞ non-hedgerow (CK).The value of ratio of output to input of H15H treatment was 1.52,which was the highest value among different treatments.Conclusions] Although the treatment of terracing hedgerow 2 (H15H) needs more labour force,however,results in the higher hedgerow yield and ratio of output to input than other treatments as well as stronger anti-scourability.Thus,the traditional terracing hedgerow with 15 cm lynchet is recommended in the remote mountainous regions of Southwest China,even should be recommended often and used extensively in the similar climatic regions in other countries.