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.

Smallholder Adoption of Soil and Water Conservation Practices in Northern Ghana

Both governmental and non-governmental organizations are engaged in the promotion of soil and water conservation practices in Northern Ghana, but adoption is believed to be low. This study thus examines the determinants of conservation practices adoption by farming households in the area. Data for the study were collected from 445 households located in 15 communities in Northern Ghana. Univariate, bivariate and multivariate probit models were used to analyse the decision to adopt six conservation practices in the area. Results show that the major determinants of adoption are plot and cropping characteristics such as location; and socio-economic and institutional variables such as number of contacts with extension officers, membership in farmer association and distance to major market. A policy implication of the study is the strengthening of extension service in the area to significantly boost conservation adootion.

Driving forces and their interactions of soil erosion in soil and water conservation regionalization at the county scale with a high cultivation rate

Soil erosion control based on county scale Soil and Water Conservation Regionalization(SWCR)is an essential component of China's ecological civilization construction.In SWCR,the quantitative analysis of the spatial heterogeneity and driving factors of soil erosion among different regions is still lacking.It is of great significance for soil erosion control to deeply examine the factors contributing to soil erosion(natural,land use,and socioeconomic factors)and their interaction at the county and regional levels.This study focused on a highly cultivated area,Hechuan District of Chongqing in the Sichuan Basin.The district(with 30 townships)was divided into four soil and water conservation regions(Ⅰ-Ⅳ)using principal component and hierarchical cluster analysis.The driving factors of soil erosion were identified using the geographical detector model.The results showed thatⅰ)the high cultivation rate was a prominent factor of soil erosion,and the sloping farmland accounted for 78.4%of the soil erosion in the study area;ⅱ)land use factors demonstrated the highest explanatory power in soil erosion,and the average interaction of land use factors explained 60.1%of soil erosion in the study area;ⅲ)the interaction between natural factors,socioeconomic factors,and land use factors greatly contributes to regional soil erosion through nonlinear-enhancement of double-factor enhancement.This study highlights the importance of giving special attention to the effects of land use factors on soil erosion at the county scale,particularly in mountainous and hilly areas with extensive sloping farmland and a high cultivation rate.

The regional difference in engineering-control and tillage factors of Chinese Soil Loss Equation

Accurate assessment of soil erosion is an important prerequisite for controlling soil erosion.The engineering-control(E)and tillage(T)factors are the keys for Chinese Soil Loss Equation(CSLE)to accurately evaluate water erosion in China.Besides,the E and T factors can reflect the water and soil conservation effects of engineering-control and tillage practices.But in the current full coverage of soil erosion surveys in China(such as soil erosion dynamic monitoring),for the same practice,the E or T factors are assigned the same value across the country.We selected 469 E and T factors data based on runoff plots from 73 publications,and they came from six soil and water conservation regions.Correlation analysis,regression analysis,and nonparametric tests were used to determine the comparability of the data,and it was proved that the runoff plots dimensions are consistent with the local topography.The results of one-way ANOVA and nonparametric tests for E and T factors in different regions showed that the engineering-control practices have good soil and water conservation effects and weaken the regional differences of other environmental factors,so there were no significant differences in E factors between different regions.However,there were significant differences in T factors between different regions,and the geodetector was applied to explore the intrinsic driving force of the spatial distribution of T factors.The results of the geodetector showed that the dominant driving forces of the spatial distribution of different types of tillage practices were not completely the same.When using CSLE to calculate water erosion,the E factor of the same practice can be used uniformly throughout the country,and the T factor needs to be considered and selected according to regional differences.At the same time,when choosing tillage practices in each water and soil conservation region,practices with better sediment reduction benefits should also be selected according to the regional environmental conditions.

Assessment of the determinants that influence the adoption of sustainable soil and water conservation practices in Techiman Municipality of Ghana

This paper assesses the relationship between farmer characteristics and the degree to which nine soil and water conservation practices (SWCPs) are adopted by 300 maize farmers in Techiman Municipality,Ghana.Farmers were surveyed for their adoption of nine SWCPs,and 24 other characteristics including demographics,socio-economic factors,risk factors and costs of production.Sustainable soil and water conservation practices (SWCPs) in sub-Saharan Africa such as Ghana are important because they have positive effects on yield,increase sustainability of farming,stop degradation and reduce soil erosion.The adoption of sustainable soil and water conservation practices in the agricultural industry of Ghana has been variable.This study aims to explain differences in farmer adoption of SWCPs,by assessing factors that vary with the number of different SWCPs used by farmers.Hence,the Poisson model was used.The results show that farmer's household size,farm size,access to credit services and formal training of maize farmer have a positive significant association with the number of soil and water conservation practices adopted by maize farmers while distance to nearest output market,distance to input center,access to extension services,and risk of pest and diseases have a negative significant association with the number of soil and water conservation practices adopted by maize farmers at 5% significance level.The study concludes that any further research in Techiman Municipality on soil and water conservation practices should acknowledge the mixture of personal and demographic,institutional,socio-economic and risk factors.This suggests that agricultural polities formulated by the government should be aimed at supporting maize farmers to have access to extension service contact for frequent disseminating of agricultural technology information which is likely to increase the rate of adoption of soil and water conservation practices.

三峡库区水土流失遥感监测及治理研究

三峡库区是长江流域生态环境系统的重要环节,库区生态环境问题备受关注。水土流失是影响三峡库区生态安全、制约库区发挥生态屏障功能的关键环境问题之一。2020—2022年,水利部水土保持监测中心的三峡库区水土流失遥感监测站组织实施了基于遥感技术的三峡库区水土流失动态监测,结合野外考察和数值模拟等手段,对库区土壤侵蚀因子与侵蚀模数进行计算,并对水土流失防治效益进行评价。结果显示:(1)林地和耕地是水土流失发生的主要区域;(2)在相同的土地利用模式下,地形较陡的区域更易发生强度较大的水蚀;(3)2020—2022年,库区水土流失面积呈减少趋势,减少速率约为264 km^(2)/年,水土保持措施面积则以865 km^(2)/年的速率增加,取得较好治理效果。在进一步工作中,可针对性地在坡度较大的水蚀区进行合理的水保措施布设,以进一步提高库区水土流失治理成效。本研究可为三峡库区水土流失治理和水保措施规划以及长江流域生态系统建设提供科学依据。

生物诱导碳酸钙沉淀在改善土壤侵蚀中的应用

【目的】雨、雪、波浪、风等作用常会引起土壤侵蚀。生物诱导碳酸钙沉淀技术(MICP/EICP)由于环境友好的特点已成为岩土和地质领域的研究热点之一。为了探究MICP/EICP在土壤抗侵蚀性方面的效果,【方法】介绍了MICP/EICP的矿化过程,基于现有成果总结了MICP/EICP改善不同类型土壤侵蚀效果。【结果】结果显示:对于土壤适应性,MICP处理粗砂的无侧限抗压强度和CaCO_(3)含量高于EICP,而在粉细砂中结果相反。对于遇水崩解特性,MICP改性黏土中25μm以下颗粒质量减少,75~250μm颗粒质量分数增加,团聚体变大,有效降低了黏土、黄土、黏性紫色土崩解速率和崩解率。对于波浪侵蚀特性,随喷洒固化次数由1增加到4,海岸砂质边坡侵蚀速率呈对数下降,固化18次后,30次潮汐变化下坡角几乎不变。对于切向水流侵蚀特性,1 g/L的黄原胶溶液结合MICP固化2次的样品和0.5 mol/L胶结液结合掺入0.2%纤维所得到的固化土的抗侵蚀性优于单纯高剂量MICP处理的结果。对于风蚀,MICP固化时,0.25 mol/L胶结液可达到抗风蚀效果,而EICP反应较快应加入抑制剂。对于多次干湿和冻融循环侵蚀,MICP/EICP处理试样的强度和侵蚀量都好于未处理试样,EICP处理砂土样的耐久性效果不如MICP明显。【结论】结果表明:MICP适用于粗粒土,生成的CaCO_(3)整体性好;EICP脲酶分子小,工艺简单,可应用于细粒土中,但生成的CaCO_(3)较松散。MICP/EICP作用可有效降低细粒土的遇水崩解特性,有效降低海岸砂质边坡的波浪侵蚀,与纤维或生聚物结合可改善固化土的脆性,抵抗切向水流的侵蚀。低浓度的胶结液配方即可抵抗风蚀。MICP/EICP可提高固化土的耐久性。

Soil erosion assessment by RUSLE with improved P factor and its validation:Case study on mountainous and hilly areas of Hubei Province,China

The Revised Universal Soil Loss Equation(RUSLE)is widely used to estimate regional soil erosion.However,quantitative impacts of soil and water conservation(SWC)measures on conservation practice factor(P)of the RUSLE remain largely unclear,especially for the mountainous and hilly areas.In this study,we improved the RUSLE by considering quantitative impacts of different SWC measures on the P factor value.The improved RUSLE was validated against the long-term(2000-2015)soil erosion monitoring data obtained from 96 runoff plots(15—35°)in mountainous and hilly areas of Hubei Province,China;the result presented a high accuracy with the determination coefficient of 0.89.Based on the erosion monitoring data of 2018 and 2019,the Root Mean Square Error of the result by the improved RUSLE was 28.0%smaller than that by the original RUSLE with decrement of 19.6%—24.0%in the average P factor values,indicating that the soil erosion modelling accuracy was significantly enhanced by the improved RUSLE.Relatively low P factor values appeared for farmlands with tillage measures(P<0.53),grasslands with engineering measures(P<0.23),woodlands with biological measures(P<0.28),and other land use types with biological measures(P<0.51).The soil erosion modulus showed a downward trend with the corresponding values of 1681.21,1673.14,1594.70,1482.40 and 1437.50 t km^(-2)a-1 in 2000,2005,2010,2015 and 2019,respectively.The applicability of the improved RUSLE was verified by the measurements in typical mountainous and hilly areas of Hubei Province,China,and arrangements of SWC measures of this area were proposed.

基于无人机倾斜摄影遥感技术的水土保持动态监测方法研究

为了能够充分了解土壤侵蚀分布,及时掌握水土流失变化趋势,提出基于无人机倾斜摄影遥感技术的水土保持动态监测方法。利用无人机从多个角度采集监测区域影像数据,并实施辐射定标和大气校正预处理,基于遥感影像数据提取土壤可蚀性因子、土地利用因子、植被覆盖监测因子、坡度因子,通过计算获取水土保持系数并划分等级。监测结果表明:区域1水土保持系数呈现“V字形”,区域2水土保持系数整体呈现“一字型”,区域3水土保持系数整体呈现逐渐上升状态。

Assessing the soil erosion control efficiency of land management practices implemented through free community labor mobilization in Ethiopia

This study aimed to assess the influence of conservation practices (P) and cover management (C) on soil loss reduction by determining it at the scale of landscape units in 16 systematically selected watersheds. Focusing on major land management practices implemented through free community labor mobilization, the assessment combined remote sensing techniques, field observation, and expert as well as local knowledge. The results show an average net decrement of 39% ( ± 19%) in the P factor value and 8.9%( ± 21%) in the C factor value after implementation of land management practices. P factor value re-duction is linked to a high area coverage of level structures, while increases in the P factor value are associated with poor quality of structures, inappropriate practices, and wide spacing between structures on steep slopes. C factor value reduction is observed in non-arable shrub- and bushland with enriched area closure, whereas increased C factor values are associated with open access grasslands and untreated croplands. The overall change in P and C factor values resulted in a 42% ( ± 28%) relative soil loss re-duction. The demonstrated approach makes it possible to assess spatial and temporal dynamics in the P and C erosion factors and to estimate spatially disaggregated changes in the P and C factor values. This can help to improve parameterization of inputs for erosion modelling and to assess their relative soil loss effect. The approach provides valuable feedback on watershed planning processes and supports informed decisions regarding the appropriate selection of land management practices.

贵州水土保持建设以奖代补试点工作成效及实践经验

为鼓励和引导社会力量和广大群众积极参与水土保持工程建设,创新水土保持工程建设管理和投入机制,充分发挥财政资金撬动作用,加快推进水土流失治理,贵州积极开展水土保持以奖代补试点工作。在水土保持工程建设管理、资金投入及制度建设等方面实现了改革创新,促进了社会资本与水土流失治理工作的深度互融、良性互促,加快了水土流失治理步伐。本文在总结经验的同时,对今后开展以奖代补工作进行了思考探讨。

基于灰色关联分析的根-土复合体对边坡加固效应

为了深入探究不同植物根系的边坡加固效应,本文结合相关工程,通过MIDAS有限元软件研究了不同根系长度、倾斜角度对根-土复合体抗剪强度的影响规律,并计算相应因素下根-土复合体加固边坡的安全系数,最后对结果进行灰色关联分析。分析结果对植物护坡实际工程应用有一定指导意义。

中国水土保持措施分类

水土保持措施分类是土壤侵蚀调查、水土保持规划、水土保持措施推广应用、以及效益评价的重要基础。笔者在总结前人研究成果的基础上,提出了水土保持措施分类系统。分类的原则兼顾科学性、适用性和定量化。该分类将我国水土保持措施分为生物措施、工程措施和耕作措施3个一级类,然后再划分出二级和三级类,共包括32个二级类型和59个三级类型。希望该分类系统起到抛砖引玉的作用,能引起对水土保持措施分类更广泛的关注和讨论,不断完善我国水土保持措施分类系统,服务于水土保持实践。

东北地区水土保持措施因子研究

东北地区土壤流失日益严重,亟需了解各种措施的水土保持效果,为水土保持规划和土壤流失预报提供科学依据。利用4个小流域17个径流小区总计343次产流产沙观测资料,计算并比较了本区7种主要水土保持措施因子值。水平台田和水平坑的工程措施因子值分别为0.020和0.061;灌木梗和封禁的生物措施因子值分别0.054和0.363。大豆顺坡种植、横坡种植和地梗植物带的耕作措施因子值分别为0.624、0.257和0.186。研究成果可为应用土壤侵蚀模型进行土壤流失预报服务。

西南“旱三熟”地区不同保护性耕作措施对农田土壤生态效应及生产效益的影响

针对我国西南地区旱作农田土层浅薄、水土流失严重、季节性干旱多发等问题,以常规平作（T）、垄作（R）、平作＋秸秆覆盖（TS）、垄作＋秸秆覆盖（RS）、平作＋秸秆覆盖＋腐熟剂（TSD）、垄作＋秸秆覆盖＋腐熟剂（RSD）6种措施作为处理,连续2年进行大田对比试验,研究不同保护性耕作措施对西南＂旱三熟＂种植区农田土壤生态要素、产量和水分利用效率的影响。结果表明,保护性耕作措施可以有效地改善土壤有机质和养分状况,且对酸性土壤有一定的改良作用,其中有秸秆覆盖的4个处理显著增加了土壤有机质、全氮、全钾、碱解氮含量;可改善土壤水分状况,增强作物的抗旱节水能力,各处理0~80 cm土层2年平均贮水量排序为：RSD（258.82 mm）〉TSD（252.40 mm）〉RS（250.19mm）〉TS（246.66 mm）〉R（239.19 mm）〉T（235.87 mm）;可降低7月份表层土壤温度,缓解夏季高温对玉米后期生长发育造成的伤害,其中有秸秆覆盖的4个处理对5 cm和10 cm土层温度有显著降低效应;可抑制杂草生长,具有良好的控草效应,其中TS、RS、TSD、RSD处理的杂草高度、密度和生物量均比T和R有极显著下降;可促进蚯蚓的繁殖和生长,使农田生态环境得到明显改善。总体来看,秸秆覆盖措施可以改善土壤肥力,并具有增加土壤贮水、调节土壤温度、控制农田杂草和促进蚯蚓生长的作用,垄作和腐熟剂在增加土壤贮水方面有明显效果。保护性耕作模式显著提高了作物的产量和水分利用效率,增加了经济收益。2年系统平均产量和水分利用效率排序为：RSD〉RS〉TSD〉TS〉R〉T（CK）,总产值和纯收入排序为RS〉RSD〉TSD〉R〉TS〉T（CK）。在各处理中以RSD、RS两种模式的综合效果最好,在西南＂旱三熟＂种植区具有很好的推广前景。

聚合物在水土保持中的应用

介绍了近年来聚合物在水土保持中的应用 ,聚合物通过创建和稳定团粒结构 ,增强土壤的渗透性及抗侵蚀能力 ,可有效地抑制了水土流失。聚合物的性质。

黄河泥沙变化研究现状与问题

泥沙问题在黄河研究及其各类规划中占有不可或缺的重要地位。基于水文站资料,对黄河及其支流泥沙的时间和空间变化规律已有较清晰的结论,明确了其泥沙变化是气候(降雨)及人类活动综合作用的结果,人类活动是20世纪70年代特别是进入21世纪以来黄河泥沙减少的主要原因。20世纪黄河泥沙减少主要是由于水利水保工程的拦蓄作用,21世纪以来的减少主要为规模化恢复植被的坡面阻控作用。由于各项水土保持措施及其耦合对泥沙的作用机理和过程研究不够深入,因此目前的水土保持措施减沙研究方法缺乏理论支撑,基础资料质量不高,以及气候和人类活动的不确定性等,导致水保法等对各项措施减沙现状分析及未来预测结果难以令人信服,直接影响黄河治理决策。建议集中科研力量,对典型流域开展"解剖麻雀"的方式,系统研究,构建科学方法,深刻认识气候及水土保持措施、开发建设等人类活动对河流水沙的影响。

环境因子对香根草生长习性的影响

环境因子对香根草生长习性的影响夏汉平，敖惠修，何道泉（中国科学院华南植物研究所，广州５１０６５０）ＥｆｆｅｃｔｏｆＥｎｖｉｒｏｎｍｅｎｔａｌＦａｃｔｏｒｓｏｎＶｅｔｉｖｅｒＧｒａｓｓＧｒｏｗｔｈ．￥ＸｉａＨａｎｐｉｎｇ；ＡｏＨｕｉｘｉｕ；ＨｅＤａｏｑ...

北京密云石匣小流域水土保持措施对土壤侵蚀的影响研究

水土保持措施的实施可有效地控制土壤侵蚀 ,不同的水土保持措施存在不同的水土保持效益值。利用北京密云石匣共 2 0个坡面径流试验小区的野外观测资料 ,分析得出了北京石匣小流域不同水土保持措施下的水土保持效益值 ,其中免耕 (玉米 )为 0 .2 80 ,梯田 (玉米 )为 0 .142 ,人工草地为 0 .0 6 3,荒草地为 0 .0 45 ,水平条林地为0 .0 2 5 ,鱼鳞坑林地为 0 .0 19。人工草地、荒草地、水平条林地和鱼鳞坑林地有显著的水土保持效益 ,但它们之间的水土保持效益并无显著差别。坡耕地 (16 .8°)的年均侵蚀模数为 145 3.8t/ km2 ,远大于土壤自然形成速度和北方石质山区的允许土壤流失量。其研究结果可为土壤侵蚀模型预报、水土保持规划。

应用流量历时曲线分析黄土高原水利水保措施对河川径流的影响

流量历时曲线(Flow Duration Curve,FDC)是用于分析流域径流特征及其变化的有效方法之一。以长序列日流量为基础,采用FDC方法并结合各流域的径流量时间变化趋势分析方法,研究了黄土高原佳芦河、秃尾河、延河和湫水河等4条流域流量变化的基本特征;通过临界年份前后两个时段序列及不同年代序列的流量历时曲线变化的比较,分析了流域径流过程对大面积水土保持措施的响应。结果表明:随水土保持措施累积面积的不断增大,佳芦河、湫水河、秃尾河的径流量逐年减少,且水土保持措施对高流量部分径流减少的程度较低流量部分大,尤以工程措施为主的湫水河流量减少最明显。在延河流域,与临界年份前的时段相比,后期的高流量部分的径流量减小,而常水和低流量部分的径流量相对增大。尽管流域水土流失综合治理并未使河川径流量增加,但由于高流量部分流量的减少程度较低流量部分径流量减少程度大,从而使流域年内日径流量变化过程趋于均匀化。