浅谈山西省梯田埂坎资源的开发利用

机修梯田的埂坎多为复式埂,占地比例大。随着机修梯田的大面积推广,梯田埂坎合理利用问题逐步被提到重要议事日程。山西省的梯田埂坎主要为土质埂坎和石质埂坎两类。根据典型调查测算,全省梯田埂坎资源现状为7294万hm2,利用率为2315%。开发利用梯田埂坎资源,具有显著的经济效益和生态效益。虽然埂坎植物会造成一定的胁地,但其影响范围仅局限在1～3m内,其影响范围内的作物减产损失与埂坎植物的增值相比微不足道。大力开发利用梯田埂坎资源,不仅可缓解日益严重的人地矛盾、培育新的经济增长点,而且可加速丘陵山区的生态建设,其发展前景广阔。     

按“用功量”计算投资 提高机修梯田质量标准

<正> 三川河流域开展重点治理以来,机械修筑梯田在我县得到了迅速的发展。截止1992年底,全县共新建机修梯田1266.8hm~2。在组织开展机修梯田中,我们对机修梯田投资管理进行了一些探索研究,不断改革完善,由以修筑面积投资到按土方量投资,1991年又改为按“用功量”计算投资,既考虑修平土方量,又考虑土方运移距离(用功量=梯田修平土方×平均运距),并根据梯田适宜宽度要求,规定单位“用功量”计费标准,较好地解决了机修梯田中的合理计费和田面过宽或过窄的问题。其主要实施办法是: (一)加强技术指导,严格质量标准。明确规定,新建机修梯田必须做到“四结合、三达到、两不小”,即新建机修梯田与土地开发利用相结合,与流域综合治理相结合,修地与埂坎利用相结合,与深耕结合;机修梯田集中连片面积必须达到6.67hm~2以上,一般地形田面宽度必须达到10m以上,当年机耕深度必须达到     

紫花苜蓿在梯田埂坎生态空间开发中的应用研究

大规模连片机修梯田是坡改梯项目的主要工程措施,在提高梯田机械化的同时也产生了大量闲置并蕴藏巨大生产潜力的埂坎土地资源。通渭县经过多年的梯田建设实践,将紫花苜蓿作为护埂植物,不仅有利于保水保土,保证新修梯田埂坎的稳定性,而且有利于优化山区土地利用结构、发展舍饲养殖,具有良好的经济、生态和社会效益。     

三川河流域四县水土保持科技成果应用调查思考

三川河流域是国家水土保持重点治理区之一,１９８２年～１９９７年重点治理期间,广泛推广了机修梯田、新修梯田培肥增产配套措施等科技成果,取得了较好的治理效益。据调查,４县推广机修梯田３．５３３万hm＾２,径流林业整地造林１．５６万hm＾２,梯田埂坎植物利用８４６６。６７hm＾２,坝地防洪保收２２６６。６７hm＾２。其特点是规模大,标准高,效益好。在加强水土保持科技成果推广应用过程中,应认真研究解决好提高认识,     

紫色砂页岩区“土石混合梯坎+黄花菜梯埂”梯田技术应用及效益分析

紫色砂页岩区坡耕地水土流失严重,梯田是治理坡耕地水土流失的有效措施。"土石混合梯坎+黄花菜梯埂"梯田技术就是下部毛条石梯坎、上部土质梯坎,梯埂种黄花菜,组成较为稳定的梯田埂坎。该技术比毛条石坎梯田投资少,比土坎梯田稳定性强、埂坎占地少,具有较好的生态、经济和社会效益,可为紫色砂页岩区坡耕地综合治理提供有效途径,值得大力推广应用。     

陇西县利用贷款加快梯田建设步伐

甘肃陇西历届县委、县政府始终把梯田建设作为发展旱作农业的一项根本措施来抓，从依靠人背肩挑到人机结合，再到近几年以机修梯田为主，走出了一条贷款机修、改土改田、治水治贫的新路子。到2004年底，全县梯田面积累计达到5．71万hm^2，其中机修梯田面积1．17万hm^2。     

通渭县贷款建设机修梯田的成效与做法

通渭是甘肃贫困农业县之一,水平梯田是当地农业生产的基本农田。近年来,面对人工梯田建设严重滑坡的局面,通渭县适时探索和发展贷款建设机修梯田,取得了显著成效。介绍了主要经验和做法,并提出了存在的主要问题和建议。     

彭阳县机修梯田建设的经验

彭阳县自建县以来狠抓机修梯田建设,截至2008年底机修梯田面积已达到4.4万hm2,人均新增机修梯田面积0.174 hm2。机修梯田建设与流域综合治理有效地蓄集了降雨径流,减少了水土流失和洪涝灾害,人民生活水平得到较大提高,生态步入良性循环的轨道。介绍了机修梯田的设计、施工及验收管理经验,并提出了机修梯田建设应注意的几点事项。     

黄土丘陵沟壑区不同年限机修梯田土壤水分变化规律研究

以黄土丘陵沟壑区永和县2013年、2015年和2016年机修梯田为研究对象,对不同年限机械梯田的土壤含水量垂直动态变化及土壤蓄水效益进行了测定分析。结果表明:不同年限机修梯田在不同深度土层的土壤含水量变化幅度差异较大,含水量最大变幅出现在坡耕地0-20 cm土层;不同年限机修梯田不同深度土层土壤含水量变化规律与降水量的季节性变化趋势相同,趋势线形状呈现出倒"V"形,峰值均出现在7月下旬;0-20 cm和40-60 cm土层,2013年的机修梯田储水能力优于2016年的机修梯田,且不同年限机修梯田的储水能力均不同程度地高于坡耕地;在相同土层深度,2013年的机修梯田土壤含水量稳定性优于2015年和2016年的机修梯田,且不同年限机修梯田的土壤含水量稳定性均不同程度高于坡耕地;不同年限机修梯田,随土层深度增加,降水和其他气象因素对土壤含水量的作用减弱;0-20 cm、0-40 cm和0-60 cm的土壤蓄水能力,2013年的机修梯田最高,2016年的机修梯田较低。     

山西省的梯田埂坎资源

据调查,山西省的梯田埂坎类型,依筑埂材料划分主要有土质埂坎和石质埂坎两大类.土质埂坎依据不同部位土体的密实程度又可分为硬埂、软埂和复式埂.石质埂坎按砌筑方式可分为干砌石坎和浆砌石坎,从埂坎结构型式上又可分为单墙式和双墙式.埂坎占地比率是测算埂坎资源量的重要指标,据典型调查加权平均计算,全省梯田复式埂占地率15.22%,土质硬坎占地率7.35%,石质埂坎占地率7.65%,埂坎平均占地率8.21%. 根据1996年底全省梯田面积统计核实资料和不同埂型平均占地率测算成果,求得全省梯田埂坎资源面积共计7.294万hm2,其中,土质硬坎3.548万hm2,复式埂2.851万hm2,石坎0.895万hm2.     

红壤坡地坡改梯水土保持效应分析

应用江西典型红壤坡地梯田与坡耕地小区的观测资料,对坡改梯的水土保持效应进行了分析研究。结果表明:坡耕地改梯田后蓄水保土效益显著提高,蓄水效益高达67.6%,保土效益达85.0%以上;梯壁植草能大大提高梯田的蓄水保土效益,采取前埂后沟+梯壁植草方式的水平梯田与梯壁不植草的对照水平梯田比较,其蓄水效益达59.7%,保土效益达98.2%,适宜在南方红壤坡地广泛推广。     

Terracing and accelerated soil loss on rwandian steeplands: A preliminary investigation of the implications of human activities affecting soil movement

Throughout Rwanda, terracing was reintroduced in 1973 as the major conservation practice to minimize soil loss on its steep agricultural lands.¹ Terracing has been partially successful in reducing soil losses resulting from nonchannelized runoff, the goal of this practice. However, because of the widespread fragile environmental conditions in the highlands, soil fertility has decreased and soil acidity increased in numerous fields as a direct result of the terracing. To maintain sufficient agricultural yields, within the constraints of a low resource agricultural system, farmers have responded to the acidity and soil fertility problems by systematically removing a portion of the terrace berm during field preparation. This practice, in response to the changing environmental situation due to terracing, results in significant amounts of soil displaced downslope year after year. This human-induced soil erosion process seriously counters many of the intended benefits of terrace construction and is contributing to the land degradation problem. The results of this study emphasize the need for both conservation strategies and the measurement of soil loss to be sensitive to human-induced as well as natural erosional processes. By not considering the human response to terrace construction, the benefits of this conservation practice have been seriously offset.     

王家沟流域低产田的改造与培肥

王家沟流域在综合治理的同时,从改造坡耕地入手,坚持30年梯田建设,把一片瘠薄、干旱、低产农田,建设和培肥成为旱涝保收,高产稳产农田,为黄土高原坡耕地治理树立了典范,积累了丰富经验。本文通过多年观测、调查资料,全面分析总结了王家沟流域梯田建设培肥的经验与效益,为坡地修梯田、低产变高产提供科学依据。     

黄土高原水平梯田的蓄水保土效益分析

 在整理、分析黄土高原西峰等水土保持试验站径流、泥沙观测资料的基础上,研究了该地区水平梯田的蓄水保土效益。结果表明:其效益的平均值为867%和877%,但差异悬殊,主要是受暴雨、大暴雨质量的影响。次降雨综合参数PI、汛期降雨量和年产流降雨量分别小于200mm2/min、350mm和125mm时,蓄水保土效益均为100%,大于这些数值时,效益降低,两者呈负相关;同时,梯田的质量也影响蓄水保土效益。     

Modified solar insolation as an agronomic factor in terraced environments

We present a model that calculates incident solar radiation falling on terraced and unterraced fields in steep slope environments. The results are presented as a function of altitude, latitude, slope aspect, slope angle, and season. The net solar benefit or cost from slope leveling (terracing) differs significantly according to these situational factors. For instance, terracing will confer a net direct solar radiation benefit of 15 per cent on south‐facing 30‐degree slopes at the Equator for a typical growing season; it will reduce net annual direct solar receipt by 21 per cent on south‐facing 30‐degree slopes at 45° N latitude. Modified solar radiation must be considered as potentially important in the historical origins, functioning and abandonment of terracing. It should be a component in agronomic evaluation of modern terrace construction, restoration, or maintenance. Copyright © 2000 John Wiley & Sons, Ltd.     

陕南土石山区坡改梯对坡面稳定性的影响

梯田是土石山区水土流失治理的主要措施。以陕南土石山区为研究对象,研究坡耕地改建成梯田后对坡面整体稳定性的影响,采用实地调查取样、室内试验和软件分析相结合的方法,分析了坡改梯前后梯田土层厚度、田坎坡度以及田面宽度对梯田坡面稳定性的影响。结果表明:（1）15°坡面修建梯田后坡面安全系数降低了45%,25°坡面修建梯田后坡面安全系数降低了73%,15°坡面修建梯田稳定性优于25°坡面;（2）在相同的坡长和坡度下,修建梯田后坡面安全系数与土层厚度成正比,与田坎坡度和田面宽度成反比。研究结果可为土石山区梯田的断面布局提供理论依据。     

黄土高原丘陵区坡改梯后的土壤质量效应

采用时空互代法,以黄土丘陵区纸坊沟流域不同年限梯田为研究对象,选取坡耕地为对照,分析了坡耕地改造梯田后,土壤物理、化学和生物学性质的演变过程.结果表明,黄土丘陵区坡耕通过工程措施改造为梯田当年,在土壤扰动和水土流失双重作用下,土壤物理、化学和生物学质量呈现不同程度下降或没有显著变化.随着改造年限的延长,土壤质量显著提高...     

Soils of Agricultural Terraces with Retaining Walls in the Mountains of Dagestan

Soil-archeological studies of agricultural terraces with retaining walls in the area of construction of the Gotsatlinskaya Hydroelectric Power Station in Khunzakh district of the Republic of Dagestan have been performed. The morphogenetic and chemical properties of the anthropogenic soils (Anthrosols) in different parts of the terrace complex are analyzed. It is argued that slope terracing in the mountains ensures the development of thicker soil profiles with pronounced genetic horizons. The soils of agricultural terraces store important information of the paleoenvironmental history and land use. A characteristic feature of the Anthrosols of agricultural terraces is a relatively even distribution of gravelly material of up to 5 cm in diameter in the plow layer. The soils of terraces are characterized by the high variability in their properties within the entire terrace complex and within the particular terraces.     

Runoff and soil loss from bench terraces. 2. An event- based erosion process model

Despite widespread bench terracing of rainfed hillsides in upland West Java, soil loss rates remain high. This paper reports measurements of sediment yield from terrace risers and beds and from terrace units made during three consecutive rainy seasons. The results demonstrate that soil loss from the terraces occurs in two stages: rainfall‐driven transport by splash and shallow overland flow (wash) from the terrace riser and bed to a central drain is followed by a combination of onward wash transport of fine sediment and entrainment by runoff of coarser sediment deposited in the drain. A model (TEST: Terrace Erosion and Sediment Transport) was developed, describing these processes as a function of vegetation and soil surface cover and the presence of a layer of deposited sediment. The model was calibrated using some of the measured sediment yield data and subsequently tested by simulating the remaining data. The results were satisfactory and modelled fractions of sediment transported by splash, wash and flow‐driven runoff transport generally compared well with observed fractions of fine and coarse particles in eroded sediment from the various plots.     

湘西北退耕还林初期坡面产流产沙规律研究

为科学合理地评价湘西北退耕还林生态效益,对湘西北女儿寨小流域3个地质类型区的11个退耕还林类型进行定位观测研究。结果表明：1）同一地质类型区,各退耕还林类型在退耕还林初期可不同程度地减少地表产流量和产沙量,其中板页岩类型区地表产流量减少29．45％、产沙量减少47．02％,花岗岩类型区地表产流量减少56．54％、产沙量减少64．04％,石灰岩类型区地表产流量减少14．16％、产沙量减少36．27％;2）在退耕还林初期,坡改梯工程措施能大幅减少地表产流量和产沙量,退耕还林结合坡改梯工程措施后,其地表产流量和产沙量仅为坡耕地直接退耕还林类型平均值的34．92％、3．66％;3）地表产流量和产沙量随降雨量下降而急剧减少,各退耕还林类型径流小区在降雨量大于50mm的坡面,平均产流量和平均产沙量分别占年平均总产流量的52．17％和年平均总产沙量的70．79％。