Benefits of Conservation Agriculture on Soil and Water Conservation and Its Progress in China

Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture （CA） is a system approach to soil and water conservation, high crop productivity and profitability, in one word, it is a system approach to sustainable agriculture. Yet, because conservation agriculture is a knowledge-intensive and a complex system to learn and implement, and also because of traditions of intensive cultivation, adoption rates have been low, since to date, only about seven percent of the world＇s arable and permanent cropland area is farmed under conservation agriculture. The practice and wider extention of conservation agriculture thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to conserve soil and water and improve sustainability over the long term. This paper described terms related to conservation agriculture, presented the effects of conservation agriculture on soil and water conservation, crop productivity, progress and adoption of CA worldwide, emphasized obstacles and possible ways to increase CA adoption to accelerate sustainable development of China agriculture.

Relationship Between Soil and Water Conservation Practices and Soil Conditions in Low Mountain and Hilly Region of Northeast China

The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.

Study on Water and Soil Conservation Effects of Grassland Based on Live Vegetation Volume at Various Time Scales

Based on the observation data of rainfall,vegetation,runoff and sediment yield in the experimental plots located in Hetian Town,Changting County of Fujian Province during 2007-2010,the changing characteristics and interrelation of live vegetation volume of grass,rainfall parameters,and water(soil)conservation effect RE(SE)were analyzed at four time scales of rainfall event,month,season,and year.The results showed that with the increase of time scales,the rainfall and vegetation indicators increased or decreased more or less,and the variation range of RE was small,while SEslowly decreased.The mean REchanged by 10%-20% at different time scales,and the observed water conservation effect of the grassland was the best at season scale while the worst at year scale.The soil conservation effect of the grassland was the best at month scale and the worst at season scale.The water conservation effect of the grass was mainly controlled by rainfall factors,including rainfall duration and precipitation at rainfall event scale,and the maximum intensity of precipitation within 30 min at longer time scales.However,the soil conservation effect of the grass was mainly controlled by vegetation factors,including the contribution of the litter on soil surface at rainfall event scale,the interaction of rainfall and vegetation at month and season scales,and the live vegetation volume of the grass at year scale.Consequently,at different time scales,the factors influencing water and soil conservation changed and interacted,and the observed water and soil conservation effects were also different,indicating that the influence of time scales deserves attention in both research and management practices.

Application of Temporary Technology for Soil and Water Conservation in Crop Protection

The increasing of highway engineering construction makes soil and water loss surrounding highway and also influences the growth of crops around, To control soil and water loss, new engineering measures are put forward to protect soil and water and prevent crops from being damaged.

Position and Role of the Soil and Water Conservation in Building Ecological Province of Anhui

According to the strategic position of ecological environment in building ecological province of Anhui, we discussed the position and role of soil and water conservation in ecological environment construction and ecological province, and put forward development suggestion of soil and water conservation under new situation.

Study on Evaluation Method of Ecological Restoration for Soil and Water Conservation in Ningxia Hui Autonomous Region

On the basis of deeply understanding the domestic existing evaluation method of ecological restoration for soil and water conservation, under the premise of analyzing characteristics of current commonly used evaluation index of ecological restoration, based on the actual situation in Ningxia Hui Autonomous Region, taking objectivity, independence and operability as the principles, nine evaluation indexes were selected, and a set of comprehensive evaluation method of ecological restoration for water and soil conservation based on AHP was constructed. The hundred mark system corresponded with ecological restoration level, and the weight of each index in evaluation system was calculated according to comparison matrix constructed by frontline workers of soil and water conservation. The method could be used to determine difficult degree of restoration of the disturbed and destroyed ecosystem and the rationality of ecological restoration for soil and water conservation.

A study on scheme of soil and water conservation regionalization in China

Regionalization of soil and water conservation is a base for the planning of soil and water conservation in China. It can provide scientific basis for constructing healthy eco-environment and regional management and development. It makes a brief review of related regionalization of study and makes clear the concept of regionalization of soil and water conservation. In this paper, based on synthetical analysis of the characteristics of eco-environments of China, the principles, indices and nomenclature of the regionalization of soil and water conservation are proposed. Through the construction of the regionalization of soil and water conservation collaboration platform and data reporting system, combined with existing soil and water conservation research, this paper uses the top-down and bottom-up and the combination of qualitative and quantitative methods to build soil and water conservation regionalization preliminary scheme, with 8 regions, 41 sub-regions and 117 sections divided in China.

Gully Erosion Regionalization of Black Soil Area in Northeastern China

Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fertile farmland there. Regionalization of gully erosion can reveal the spatial distribution and regularity of the development of gully erosion. Based on the eco-geographical regional background features of the black soil area, this study combined the regionalization with influencing factors of the development of gully erosion. GIS spatial analysis, geostatistical analysis, spatial statistics, reclassification, debris polygon processing and map algebra methods were employed. As a result, the black soil area was divided into 12 subregions. The field survey data on type, length, volume and other characteristics indicators of gully erosion were used to calibrate the results. Then the features of every subregion, such as where the gully erosion is, how serious it is, and why it happens and develops, were expounded. The result is not only an essential prerequisite for gully erosion surveys and monitoring, but also an important basis for gully erosion prevention.

南方崩岗调查内容与方法探讨

崩岗是我国南方水土流失的一种特殊类型,广泛分布于南方红壤区,是该区域严重的生态问题之一。第一次崩岗调查距今已近20年,相关情况已发生巨大变化。崩岗现状不清直接影响了行政管理部门对崩岗防治相关工作的规划和决策,因此急需开展新一轮崩岗调查。新时代水土保持高质量发展为崩岗调查提供了机遇,差别化分类防治和分步实施对崩岗调查提出了更高要求,现代信息技术为崩岗调查提供了新方法,以服务崩岗风险评估和防治规划为导向,在充分利用第一次崩岗调查成果基础上,补充崩岗发育的小山体调查,将典型调查改为全面普查,系统探讨崩岗调查对象与范围、调查内容、调查程序与方法,以期为行政管理部门和技术单位启动新一轮崩岗调查工作提供参考。

岷江干旱河谷土石混合边坡不同种植处理下乡土植被的生态效益

岷江干旱河谷生态环境脆弱,植被恢复困难,大规模的公路建设极易对当地生态环境造成破坏。筛选适宜的植被恢复措施对干旱地区道路边坡的乡土植被恢复重建和生态功能提升尤为重要。以岷江干旱河谷极端退化的土石混合的道路边坡为案例,选取乡土灌木和草本植物构建植物群落,进行裸地播种、播种后覆盖纤维毯和添加腐殖土后播种并地表覆盖纤维毯3种不同的种植处理,揭示了不同处理下群落结构、土壤改良以及水土保持效益的差异。发现,乡土灌草群落是干旱河谷适宜的道路边坡植被恢复模式,种植后第3年群落特征趋近于岷江干旱河谷区自然生态系统的多年生灌草植被。纤维毯覆盖+覆土处理在促进植物生长和群落构建,水土流失防治上效果最好,群落总盖度为74%,群落总生物量为506.35 g/m^(2);生长季内,与自然恢复相比小区径流量减少了87.8%,泥沙流失量降低了92.1%。土壤改良效应在3种处理之间差异不明显,但是与自然恢复样地相比,各处理均提升了边坡0-20 cm土层土壤养分。不同种植处理下植物群落结构差异是影响干旱河谷土石混合的道路边坡水土流失的关键因子。

水土保持植物措施碳汇研究综述

开展水土保持碳汇研究,分析水土保持植物措施的碳汇效应,可为全面提升水土保持碳汇能力、制定固碳增汇政策措施、科学推进水土流失综合治理工作、推动高质量发展和实现“双碳”目标提供科学依据。论述了水土保持植物措施的碳汇意义、碳汇功能内涵和机理、碳汇量的计算方法,并通过总结和分析国内外相关文献,深入分析水土保持植物措施对生态系统固碳功能、植被固碳和土壤碳库的影响,提出了以固碳增汇为目标的水土保持植物措施配置方案。

民国时期黄河上游地区水土保持建设成效与启示

民国时期,由于报刊的宣传普及、专家学者的讲演与培训、农业技术机构的设立和专门人才的培养,水土保持思想得到广泛传播,农业发展呈现新特征,林业建设和黄河治理得到了有力的推进。尽管受当时社会环境和科学技术水平的影响,黄河上游地区水土保持工作研究存在资金短缺、技术不成熟、设备落后、农民参与度不高等方面的局限性,但其在设立水土保持实验区和农业试验场、加大对水土保持的宣传普及、推进农林牧业协调发展、推进法治建设、实现乡村振兴和生态保护的协调发展等方面的做法仍然值得我们今天借鉴。

高海拔寒冷地区机场施工扰动区植被恢复物种选择研究

为筛选出可适应高海拔寒冷地区生态环境的植物物种,促进生产建设项目施工扰动区进行水土保持与植被恢复,以泸沽湖机场为试验场地,选择雪松、滇柏、冷杉、川滇桤木、窄叶火棘、迎春、红叶石楠、金森女贞、常春藤、秋英、多年生黑麦草、冷地早熟禾、白三叶等13种乔灌草植物开展现场种植试验,通过跟踪调查植物成活率、保存率、生长情况等表现,选出适宜的机场施工扰动区植被恢复物种。结果表明:雪松、滇柏、冷杉、川滇桤木、窄叶火棘、迎春、多年生黑麦草、冷地早熟禾、白三叶等在工程施工扰动区迹地恢复具有一定的适应性;红叶石楠、金森女贞和常春藤在植被修复应用的可行性有待进一步跟踪论证;秋英可结合工程实际需要进行应用。研究成果可为后续类似项目生态恢复和研究提供参考。

基于近20年《中国水土保持公报》的水土流失治理分析

水土保持是生态文明建设的重要组成部分,也是反映经济社会发展与生态环境质量动态平衡的重要综合指标。基于近20 a的《中国水土保持公报》,分析了水土流失现状,总结了水土保持工作进展,深入探究了水土流失动态变化成因及水土保持阶段性成效,研究成果对评价水土保持工作成效具有重要理论意义。研究结果表明:①与20世纪80年代末相比,2020年全国水土流失面积下降了26.6%,相较于20世纪初下降了24.4%;②2011年以前水土流失以中度及以上强度为主,2018年以后轻度流失面积占比超过60%;③水土流失综合治理是水土流失面积降低的主要原因;近20 a来,11条主要江河年总输沙量下降了72.4%,年输沙量与累计水土流失治理面积呈显著的负相关关系(R 2=0.90)。现阶段我国水土流失治理由“面”向“点”纵深推进,水土保持工作迈入高质量发展。研究成果可为我国水土保持工作评价及水土保持高质量发展提供定量数据和理论基础。

土壤不同孔隙度对川西典型植被系统水源涵养的影响

水源涵养是生态系统的重要服务功能之一,目前水源涵养的评估体系及方法还未统一,且不同方法评估的结果差异很大。以川西米亚罗林区为例,通过测定和计算典型植被地上部分的水源含养量,以及其土壤的不同孔隙度来评估其水源涵养总量。结果表明:1)不同植被下,土壤的总孔隙度差异不是很明显,但毛管和非毛管孔隙度差异明显;2)不同植被地上部分涵养水量+土壤总孔隙储水量,各植被类型涵养量差异不明显。针叶林和桦木林的涵养量最大,而混交林的最低;不同植被地上部分涵养水量+非毛管孔隙储水量,各植被类型涵养量差异很明显。针叶林的涵养量最大,而草甸的最低;但就不同植被的地上部分涵养水量+毛管孔隙储水量而言,草甸的最大,而针叶林的最低。植被系统地上部分涵养水量+其土壤毛管孔隙储水量,能较科学和准确评估植被系统的水源涵养量。

丹江口库区不同降雨类型下典型植被措施的水土保持效应

为了进一步研究丹江口库区不同降雨类型下植被措施控制土壤侵蚀的效果,以丹江口库区典型生态修复小流域为研究对象,采用坡面径流小区观测法,基于长期野外原位监测的降雨和径流泥沙数据,以裸地为对照,研究不同降雨类型下典型植被恢复措施[柏树林(Cupressus funebris,CF)、枇杷林(Eriobotrya japonica,EJ)和紫花苜蓿草地(Medicago sativa,MS)]对坡面产流产沙和土壤侵蚀的影响,分析植被措施的水土保持效应对降雨类型的响应特征。结果表明:(1)中历时、中雨量、小雨强降雨(雨型Ⅲ)是研究区常见的降雨类型,短历时、小雨量、大雨强降雨(雨型Ⅰ)和长历时、大雨量、中雨强降雨(雨型Ⅱ)发生的频率相对较低,但雨型Ⅰ所导致的土壤侵蚀最为严重,占总侵蚀量的46.79%以上,降雨量和最大30 min雨强(I 30)是控制该区域土壤侵蚀的关键降雨因子。(2)植被措施均具有显著的水土保持效应,减流减沙效益依次为紫花苜蓿草地>柏树林>枇杷林。相比于裸地,紫花苜蓿草地径流系数减少54.07%,含沙量减少50.80%,土壤侵蚀量减少65.47%,而枇杷林的径流系数、含沙量和土壤侵蚀量仅分别减少30.60%,36.21%,45.42%。植被措施在雨型Ⅲ下的水土保持效应最优,以紫花苜蓿草地效果最好,土壤侵蚀的减少量可达87.98%,而在雨型Ⅰ条件下稍差,其中柏树林的效果相对较好,侵蚀减少量为65.25%;植被措施的减流效益随着降雨量的增加逐渐降低,减沙效益则随着I 30的增加而降低。当I 30<41 mm/h,紫花苜蓿草地的减沙效果较佳;当68.8 mm/h>I 30>41 mm/h,柏树林的减沙效果相对较好,但低于41.55%。研究结果对于丹江口库区水土保持及资源可持续利用具有重要指导意义。

黄河流域砒砂岩区典型水土保持植被生长特征及限制因素研究

以内蒙古砒砂岩区鲍家沟小流域为研究区,以该流域典型水土保持植被为研究对象,探究水土保持植被的生长特征及其限制性因子。结果表明:1)砒砂岩区典型小流域的水土保持植被种类相对单一,沙棘和柠条林生长发育状态相对稳定,油松,山杏林的生长发育状态受立地条件影响较大;2)各林地土壤有机质含量在2.45~6.23 g·kg^(-1),土壤容重在1.51~1.71 g·cm^(-3),土壤含水率在10%~18%,研究区土壤紧实,肥力条件较差;3)通径分析的结果表明,土壤有机质为限制砒砂岩区人工林生长发育的直接限制性因子,坡度和坡向因子为间接限制性因子。研究砒砂岩区水土保持植被的生长发育特征,建立其生长特征与环境因子的联系,对于深入解读生态恢复过程,减轻入黄泥沙有重要意义。

近40年来黄土高原植被变化趋势及其生态效应

1999年起我国实施了退耕还林还草政策,黄土高原植被覆盖状况与土地利用结构发生了明显变化,植被覆盖大幅增加,生态质量显著改善。然而,植被覆盖的时空变化趋势却很不确定,对于其生态效应综合评估方面的研究相对薄弱。基于此,在分析归一化植被指数(NDVI)与植被覆盖度(FVC)两种指标的基础上,综述了近40年来退耕还林还草政策实施前后黄土高原植被覆盖及分布的变化情况。结果表明:①通过分析比较记录植被覆盖动态变化的5种常见数据集,发现数据源在一定程度上影响生态环境效益评价结果的真实性;②黄土高原多年来整体植被覆盖呈波动式增加,且增速随着退耕还林还草政策的实施而增大,空间分布自东南向西北方向递减,并受到生态系统格局、土地利用类型及气候变化等因素的影响;③随着植被覆盖面积增长,黄土高原生态系统水土保持效应与固碳能力逐渐增强,二者均与植被覆盖变化高度耦合。针对黄土高原生态环境治理及粮食生产水平现状,建议加强高标准农田建设,缓解退耕还林还草政策导致的耕地紧缺问题,同时加快推动生态价值转化和生态补偿力度,让“绿水青山”真正成为“金山银山”。

东北黑土区水土保持重点工程措施保存现状及其问题

[目的]系统评估国家水土保持重点工程的措施保存情况,为东北黑土区水土流失治理提质增效提供依据,促进黑土地保护和水土保持高质量发展。[方法]以2019年以前在东北黑土区实施的国家水土保持重点工程为对象,选取52个小流域的坡面治理工程和8个小流域(项目区)的侵蚀沟治理工程开展调研,共抽核325个坡面图斑和32条侵蚀沟,并对结果进行分析诊断。[结果]全区水土保持重点工程中的治沟措施保存情况明显优于坡面措施,平均保存率分别为95.00%和56.51%。坡面治理措施的保存率存在明显的类别和空间分异,侵蚀沟治理措施普遍保存完好,生态节地型措施保存率较高,个别措施在部分地区需提质增效和加强管护。[结论]今后应加强东北黑土区梯田、地埂植物带等传统措施的优化和管护,研发适应现代农业的生态节地型水土保持新措施,并探索建设黑土地水土保持技术中试基地;定期开展重点工程成效评估,提出分区分类措施推荐名录,打造不同类型示范样本。

禁牧封育对黄河源高寒草甸植被群落结构及土壤水分特征的影响

为探讨禁牧封育对黄河源高寒草甸生态系统的影响,研究选取玛沁高寒草甸作为对象,通过野外调查和室内试验,分析了禁牧封育对黄河源高寒草甸植被结构和土壤水分特征在不同禁牧封育条件下的变化情况。结果表明:(1)随着禁牧封育年限的延长,植被盖度和高度均呈增加趋势,物种多样性指数、丰富度指数和物种数呈先增加后稳定趋势,优势度指数先下降后稳定,均匀度指数变化不显著。就功能群而言,随封育年限增加,禾本科、豆科植物重要值占比呈逐步增加趋势,莎草类植物重要值占比呈先快速增加后趋于稳定的趋势,杂类草重要值占比明显下降。(2)随禁牧封育年限增加,地上生物量逐步增加,地下生物量和地上地下总生物量呈先增加后稳定趋势,禁牧封育对地下生物量的影响主要集中在0-20 cm。(3)禁牧封育对黄河源高寒草甸土壤容重、持水量及孔隙度的影响主要集中在表层(0-5 cm),随封育年限的增加,表层土壤容重呈先下降后稳定趋势,土壤饱和持水量、毛管持水量和田间持水量呈增加趋势,土壤毛管孔隙度和总孔隙度先增加后稳定,非毛管孔隙度无显著变化。与重度退化相比,封育5年样地0-5 cm土壤容重显著下降30.25%(P<0.05),饱和持水量、毛管持水量、田间持水量、毛管孔隙度和总孔隙度分别显著增加14.44%、18.36%、28.19%、18.36%、12.09%(P<0.05)。表明短期禁牧封育不仅有利于改善黄河源高寒草甸植被群落结构,而且能够增强该地区土壤水源涵养功能。