Contour Farming Suitability of the Black Soil Region in Northeast China and Its Spatial Characteristics

Contour farming technology plays a key role in reducing soil erosion,enhancing water use efficiency,and fostering sustain-able agricultural development,Despite being a straightforward yet efficacious farming technique,it has not seen widespread implement-ation in China.Considering the deteriorating quality of arable lands in the Black Soil Region of Northeast China(BSR-NEC),it is ne-cessary to investigate spatial patterns and identify suitable areas for contour farming in this region.To achieve this objective,spatial autocorrelation and grouping analysis methods were employed to classify the land into four categories of suitability for contour farming:highly suitable,moderately suitable,generally suitable,and unsuitable.The results reveal that:1)the contour farming suitable area in BSR-NEC covers 89861.32 km^(2),accounting for 21.59%of arable land as of 2020.Heilongjiang Province owns the largest suitable area of 32853.68 km^(2),and Inner Mongolia has the highest proportion of 28.89%.2)In terms of the spatial distribution,regions with higher suitability for contour farming are concentrated in the Da Hinggan Mountains region,particularly Nenjiang City(Heilongjiang Province),which has the highest area of 2593.07 km^(2).Areas with a high proportion of suitable arable lands for contour farming are mainly found in the Da Hinggan Mountains and Changbai Mountains regions,with Ergun City(Inner Mongolia)having the highest pro-portion at 47.2%.Regions with higher suitability and proportion are concentrated in the Da Hinggan Mountains region,primarily cover-ing the Inner Mongolia and Heilongjiang.3)Regarding spatial clustering,both the area and proportion of suitable contour farming areas exhibit noticeable clustering effects,though not entirely consistent.4)Group analysis results designate 148 counties in BSR-NEC as highly suitable areas,predominantly located in the Changbai Mountains region,Liaodong Peninsula,Hulun Buir Plateau,and the north and south regions of the Da Hinggan Mountains.The zoning of suitable areas for contour farming in BSR-NEC informs the strategic de-velopment of policies and measures,allowing for the implementation of targeted policies in distinct areas suitable for contour farming.This provides a valuable reference for promoting contour farming technology more effectively and efficiently.re effectively and effi-ciently.

Spatio-temporal Evaluation of Multi-scale Cultivated Land System Resilience in Black Soil Region from 2000 to 2019:A Case Study of Liaoning Province,Northeast China

It is of great significance to systematically analyze the cultivated land system resilience(CLSR) for the black soil protection and national food security.The CLSR is impacted by planting structure adjustment and cultivated land quality decline,posing major hidden dangers to food security.It is urgent to evaluate the CLSR at multiple spatio-temporal scales.This study took Liaoning Province in the black soil region of Northeast China as an example.Based on the resilience theory,this study constructed the CLSR evaluation system from the input-feedback perspective at the provincial-scale and the city-scale,and used the rank-sum ratio comprehensive evaluation method(RSR) to analyze the key influencing factors of CLSR in Liaoning Province and its 14 cities from 2000 to 2019.The results showed that:1) the time series changes of CLSR at the provincial-scale and the city-scale in Liaoning Province were similar,both showing an increasing trend.2) The CLSR in Liaoning Province presented a spatial pattern of ‘high in the west and low in the east’ at the city-scale.3) There were seven and six main influencing factors of CLSR at the provincial-scale and the city-scale,respectively.In addition to the net income per capita of rural households,other influencing factors of CLSR were different at the provincial-scale and the city-scale.The feedback factors were dominant at the provincial-scale,and the input factors and feedback factors were dominant at the city-scale.The results could provide a reference for the utilization of black soil and draw on the experience of regional agricultural planning and adjustment.

Evaluation and Driving Force Analysis of Cultivated Land Quality in Black Soil Region of Northeast China

Cultivated land is an important natural resource to ensure food,ecological and economic security.The cultivated land quality evaluation(CQE)is greatly significant for protecting and managing cultivated land.In this study,320 counties in the black soil region of Northeast China(BSRNC)represent the research units used to construct the CQE system measuring the soil properties(SP),cultivated land productivity(CLP),ecological environment(EE)and social economy(SE).The total of 19 factors were selected to calculate the integrated fertility index(IFI)and divided into grades.Simultaneously,we used the coupling coordination degree model to comprehensively analyze the spatial pattern of the cultivated land quality(CLQ)in the BSRNC,and use the structural equation model(SEM)to analyze the driving mechanism.The results show the following:1)The CLQ of 262 counties in the BSRNC is in a state of coupling and coordination,and the coupling and coordination degree presents a spatial distribution pattern of‘high in the southwest and northeast,low in the northwest and southeast’.The coordinated development degree of 271 counties is between 0.4 and 0.6,which is in a transitional state between coordination and disorder.2)The CLQ in the BSRNC is generally good,with an average grade of 3.High-quality cultivated land accounts for 58.45%of all counties,middle-and upper-quality cultivated land accounts for 27.05%,and poor-quality cultivated land accounts for 14.49%.3)The SEM analysis shows that the SP,CLP,EE,and SE all influence the CLQ.Among them,the SP has the largest driving force on the CLQ,while the SE has the smallest driving force on it.The results confirm that the main factors affecting the evaluation results are crop productivity level,normalized difference vegetation index,ratio vegetation index,difference vegetation index,and organic carbon content.When implementing protection measures in counties with a low CLQ,considering a balanced coordination of multiple systems and reasonably controlling the quality degradation are important.This study provides the current situation and driving factors of the CLQ in the BSRNC and will play an important role in black soil governance and utilization.

Temporal and Spatial Variation Characteristics of Soil Organic Carbon Content in Cultivated Land of Black Soil Region in Liaoning Province

[Objectives]To study the temporal and spatial variation of SOC content in cultivated land in black soil region in Liaoning Province.[Methods]Through the evaluation and analysis of the research data of this project and the data of the second national soil census,and using GIS technology,this paper studied the temporal and spatial variation characteristics of SOC in the black soil region of Liaoning Province,and provided a basis for improving cultivated land carbon storage and soil organic matter content.[Results]Since 1980,the SOC content in cultivated land in the black soil region in Liaoning Province has generally declined,and the spatial distribution difference has gradually decreased.From 1980 to 2018,the homogeneity of SOC distribution weakened,and the variation in a small range strengthened.The SOC content generally showed the characteristics of increase and decrease,and the changes in the area were scattered.[Conclusions]This study is of great significance to the sustainable utilization of land resources.

Change of cultivated land area and effect on ecosystem service in black soil region in Northeast China: a case study of Lishu County, Jilin Province

It is of great significance to study the influence of spatial pattern change of cultivated land on eco-system service,including the sustainable utilization and ecological protection in black soil region in Northeast China.Taking Lishu County of Jilin Province as the study area,we quantitatively evaluated soil conservation,habitat quality,carbon storage and grain production service,and analyzed the change of cultivated land and ecosystem service pattern in Lishu County from 1990 to 2020 by using Pearson correlation analysis on the correlation between cultivated land change and ecosystem service.The results show that:(1)The cultivated land area of Lishu County was reduced by 19.67 km2,the characteristics of cultivated land change are signifi-cant;(2)the overall change rate of carbon storage,habitat quality,soil conservation and grain production ser-vice in the study area was 10.82%,-0.09%,4.07%and 1.80%,respectively.They all had significant spatial differentiation features;(3)the change of habitat quality,grain production service showed a significant pos-itive correlation with the change of cultivated land area.The change in soil conservation and carbon storage were negatively related to cultivated land area.In order to promote the rational development and utilization of cultivated land in the research area,it is suggested to scientifically carry out the comprehensive utilization of cultivated land reserve resources such as saline-alkali land,strengthen the management and protection of newly added cultivated land at the same time.The results can provide scientific reference for formulating comprehensive land use planning under ecological security conditions.

Spatial distribution of soil erosion and its impacts on soil productivity in Songnen typical black soil region

Soil erosion is an important reason for land degradation.The black soil region of Northeast China is the main grain production base in China,however,the black soil productivity in this region is at risk and unsustainable now because there was few soil conservation measures in nearly 100 years of cultivation.To assess the impact of erosion on land productivity,both 210 sampling points for ^(137)Cs measurement and 112 sampling points for soil profile features were laid out on cultivated land of Songnen typical black soil region in combination with the 2010 China land use map.The current soil erosion/deposition rate and land productivity index PI were calculated over the study area,and then the PI values were predicted erosion by 20,50,100,and 200 years without soil and water conservation measures based on the current erosion rate and soil profile characteristics.The results showed that the average soil erosion rate of cultivated land in the study area was 705.8 t/(km^(2)·a),and 77.0%of the cultivated land had soil erosion rate larger than the soil loss tolerance of 200 t/(km^(2)·a).Spatially,the soil erosion rate in the northern region was greater than that in the southern region significantly,which was mainly affected by slope steepness.The relationship between soil erosion rate(SL)and slope steepness(θ)in degree was established according to the results of ^(137)Cs measured at 210 sample points:SL=556.4*θ or SL=0.464*θin mm/a(given soil bulk density is 1200 kg/m^(3)).The current mean value of PI for cultivated land was 0.59,decreasing significantly from north to south,which was mainly influenced by organic matter content.The predicted PI values decreased significantly with the increase of erosion years in the northern area.This is related to the topography of rolling and hills in the northern area with a greater soil loss rate,leading to a rapid decrease of organic matter content and the increase of sand content in the topsoil in the future.The spatial distributions of the current soil erosion rates and predicted PI values after years of erosion for cultivated land would be helpful for soil conservation policy-making.

基于土壤有机碳含量的黑土层厚度预测及影响因素分析

黑土层厚度是黑土的一项基本属性,是衡量土壤肥力和侵蚀程度的重要指标,其空间预测的研究对支撑我国黑土地保护工程、保障粮食安全具有重要意义。本文参考土壤系统分类中黑土层的诊断特征,将有机碳含量高于成土母质6×10~(-3)作为黑土层的判定标准,并利用有机碳在土壤垂向剖面上的指数分布规律,推算出黑土层厚度的计算公式。基于多目标区域地球化学调查获取的62 896个表层土壤和15 687个深层土壤的有机碳测试数据,对松辽平原黑土层厚度进行了详尽的空间预测分析,并探讨了黑土层厚度与土壤类型和气候因子之间的关系。结果显示,松辽平原黑土层厚度在0~165 cm之间,中位数为23.33 cm。黑土层空间分布呈现出显著的非均质性,整体呈西南薄、东北厚的分布特点。沼泽土和泥炭土的黑土层平均厚度最大,在60~80 cm之间,其次为黑土,平均厚度为56 cm,白浆土和草甸土的黑土层平均厚度在40~50 cm之间。黑土层厚度的空间分布与气候条件关系紧密,主要表现为与温度呈显著的负相关,与降雨量呈正相关。同时,研究发现年均温0℃是影响黑土厚度的一个重要温度阈值,当年均温高于0℃时,黑土层平均厚度在80 cm以上,并且不再随温度发生变化。随着气候变暖,年均温0℃等温线的南移可能对黑土层厚度产生重要影响。

考虑碳排放约束的耕地利用生态效率时空差异与影响因素分析——以东北黑土区29个地级市为例

为保障粮食安全,促进东北黑土区农业低碳发展,推动黑土区农业绿色高质量发展和区域协同发展提供参考。以耕作过程产生的碳排放量作为非期望产出约束,利用超效率EBM模型对2007—2021年东北黑土区耕地利用生态效率进行有效测度,进一步采用Malmquist指数模型和Tobit回归模型探究考虑碳排放约束的东北黑土区耕地利用生态效率时空差异与影响因素。结果表明:①考虑碳排放约束条件的东北黑土区耕地利用生态效率整体上呈先上升后下降再上升的“N”型态势,东北黑土区四省中黑龙江省是唯一相对有效省份,29个地级市中未达到有效状态城市占72.4%;②碳排放约束条件的耕地利用生态效率损失是投入、非期望产出冗余和期望产出不足导致的,同时技术进步变化对生产率的影响更显著;③东北黑土区耕地利用生态效率受资源禀赋、环境规制水平和政府支持力度的显著影响。基于上述研究,为提高黑土区耕地利用生态效率,应考虑黑土地的自然、生产和生态特性,优化投入结构、提高农业现代化水平、制定可持续耕地利用绿色降碳减排的发展规划。

基于GBDT的望奎县农田土壤有机碳主控因子研究

利用多源公开数据,针对于2012年搜集到的农田土壤有机碳(SOC)数据,通过梯度增强决策树(GBDT)探究SOC的主控因子,揭示SOC空间分异机理.选择国家商品粮食生产基地县和全国产量大县-望奎县作为研究区域,结果表明,GBDT模型相较于一元线性回归模型在所有的自变量上均具有更好的预测效果,总体的R^(2)为0.958,表明该模型能够很好地解释目标变量的变异;碱解氮、有效磷、气温、土壤微生物多样性、速效钾、土壤pH和降水量依次是影响有机碳含量最为显著的几个因素,其中碱解氮以33.85%的影响权重位居最高;7个环境协变量均观察到对SOC的阈值效应,且均具有两个阈值.研究发现任意两个变量都不是独立的,均存在相互作用的负值效应.表明环境变量对SOC含量的影响是一个复杂的交互作用,而不是简单的叠加.侧面证明了过度施肥并不会达到增加土壤肥力的作用,而会造成资源浪费和农田生态污染问题.

基于生态足迹法的农业水土资源承载力分析——以三江平原友谊农场为例

本文以三江平原“黑土粮仓”——友谊农场为例,应用生态足迹法对当地的水土资源承载力进行定量评估。结果表明:(1)人均农业水资源生态足迹多年平均值为5.26 hm^(2)/人,生态承载力多年平均值为1.97 hm^(2)/人,水资源生态赤字,生态压力指数平均值为2.82,水资源利用处于不安全状态;人均耕地资源生态足迹小于生态承载力,耕地资源生态盈余,生态压力指数平均值为0.69,耕地资源利用处于安全状态;(2)友谊农场农业水土资源生态足迹和水土资源生态承载力的耦合协调度总体处于一般协调状态;(3)虽然农场土地资源丰富,但水资源稀缺,该地区的水土资源承载力协调水平还有很大的提升空间。研究结果对于黑土地保护,实现农业水土资源可持续发展有重要意义。

典型黑土区防护林带和耕地土壤有机碳分布特征及其影响因素

为了合理开发利用典型黑土、阻控土壤退化、维持耕地产能和可持续利用,选择典型黑土区3个地点的杨树林带和紧邻林带的耕地为研究区,通过测定不同土层的土壤有机碳质量分数、酶活性、化学性质和总球囊霉素质量分数,结合气候因素,分析两种土地利用类型下土壤有机碳质量分数的分布特征及其影响因素。结果表明:(1)林带和耕地土壤有机碳质量分数平均值在克山县和宾县的所有土层均存在显著差异(P<0.05),且林带高于耕地,而辽源市的所有土层土壤均无显著差异(P>0.05)(2)3个地点耕地及辽源市林带土壤有机碳质量分数平均值随着土壤深度的增加而显著降低(P<0.05),而克山县和宾县林带的土层土壤均无显著差异(P>0.05)。(3)林带和耕地土壤有机碳质量分数与β-N-乙酰氨基葡萄糖苷酶活性、β-葡萄糖苷酶活性、总球囊霉素质量分数、全磷质量分数、碱解氮质量分数具有极显著的正相关性(P<0.01);林带土壤有机碳质量分数与pH呈极显著的正相关(P<0.01),与年平均气温和年平均降水量呈显著的负相关(P<0.05),与有效磷质量分数相关性不显著(P>0.05);耕地土壤有机碳与有效磷质量分数呈极显著正相关(P<0.01),与年平均气温、年平均降水量和pH相关性不显著(P>0.05)。(4)影响土壤有机碳质量分数的主要因子为总球囊霉素、碱解氮和全磷,次要因子为年平均气温、年平均降水量、β-N-乙酰氨基葡萄糖苷酶、β-葡萄糖苷酶和pH。

东北黑土地保护利用“北安模式”及推广建议

北大荒集团是东北大粮仓的重要组成部分,为国家粮食安全做出了重要贡献,总结其黑土地保护模式,为黑土地保护利用提供借鉴,为保障国家粮食安全提供路径选择。该研究利用典型案例调查法,通过实地调研与关键人物访谈,梳理黑土地保护做法与经验,总结凝练成“北安模式”。“北安模式”黑土地保护做法体现在,一是修建防护工程解决黑土变“薄”问题,打造绿色屏障,防止黑土地遭到风蚀水蚀;二是采取用养结合解决黑土变“瘦”问题,提高土壤中的有机质;三是运用深松整地解决黑土变“硬”问题,提高土壤结构的稳定性,缓解耕地板结情况。该模式取得明显的保护成效,水土流失治理面积超8 000 hm~2,黑土地有机质含量提高了2.8 g·kg^(-1),耕地质量平均已经提高0.5个等级。在运行机制上,“北安模式”黑土地保护采取“3+1”田长制、规范化生产流程与技术措施以及智慧化监测土壤墒情。为进一步推广黑土地保护的“北安模式”,建议加强高标准农田建设筑牢防护工程以促进耕地的保护和绿色利用;协同农业减污与提质增效以促进农业绿色发展;加强校企合作强化耕地科技以促进农业高质量发展;发挥服务主体优势提升社会化服务水平以协同周边地区共同保护。

黑土区坡耕地施加生物炭对水土流失的影响

为了探索生物炭对黑土区坡耕地的水土保持作用效果,于2015年在东北黑土区典型黑土带上的黑龙江省北安市红星农场3°坡耕地上的径流小区内,开展了不同生物炭施用量(0、25、50、75、100 t/hm^2)对土壤结构、持水性能、径流泥沙控制等影响的试验研究。结果表明:生物炭可有效改善黑土区土壤结构,随着生物炭添加量的增加,土壤容重随之减小,而土壤孔隙度则会明显提高;土壤饱和含水率、田间持水量和土壤储水能力均随生物炭施用量的增加而增加;适当施加生物炭对黑土区坡耕地降雨径流及水土流失具有较好的控制作用,75 t/hm^2处理具有最好的径流泥沙控制效果,其中径流控制效果好于泥沙控制;施加生物炭还可以不同程度地减少黑土区坡耕地土壤养分流失,并可以改善养分的空间分布,4种生物炭用量处理的养分含量不仅在数量上高于对照处理,而且在均匀程度上有较大的改善,减缓了坡度对土壤养分造成的坡上与坡下的差异。研究结果为东北黑土区秸秆资源的高效、绿色、循环利用提供了一条新的途径,可为黑土区坡耕地水土流失防治提供理论依据和技术支撑,对该区农业可持续发展具有重要意义。

黄河源区“黑土滩”退化草地群落类型多样性及其群落结构研究

调查了黄河源区高寒草甸极度退化产物“黑土滩”植被群落类型多样性及其群落结构特征。结果表明,分布在黄河源区高寒草甸上的“黑土滩”草地植被可分为7个类型,分别为:黄帚橐吾+铁棒棰群落、白苞筋骨草群落、铁棒棰群落、西伯利亚蓼+鹅绒委陵菜群落、摩苓草群落、甘青微孔草群落和甘肃马先蒿群落。从群落结构和已有的研究结果看,黄河源区所有类型的“黑土滩”草地都完全失去了牧用价值,短期内自然恢复的物质基础也已丧失,该类草地的恢复治理必须通过人工植被的重建来实现。

东北典型黑土区不同土地利用方式土壤水分动态变化特征

土壤水分是农业生产和区域生态系统的重要影响因子。以黑龙江省鹤山农场2号小流域为研究区域,系统研究不同土地利用方式土壤水分的动态变化过程和剖面变化特征。结果发现:不同土地利用方式土壤含水量随观察期内降雨量时间分布波动,并且总体呈降低趋势,但各变化曲线有所差异。观测时段内土壤水分变化分为相对稳定期、消耗期和补给期;土地利用方式对土壤剖面含水量的影响随土层的加深而增大,各土地利用方式的土壤含水量随土层的加深也呈现出不同的变化趋势,并且其土壤剖面含水量变化均存在季节差异。

降水年型对黑土区土壤水分动态变化的影响

利用长期定位试验,研究了黑土区不同降水年型下荒地、裸地和农田土壤水分的变化特征。结果表明,降水年型能够影响不同植被类型下土壤水分的季节性动态变化和垂直变化。丰水年不同植被类型土壤含水量均呈"V"型曲线变化,最低值出现在7月份,观测期内裸地较高;平水年呈"W"型曲线变化,分别在6月份和8月份出现两个低值,不同植被类型表现为裸地>荒地>农田;枯水年除裸地在观测后期土壤含水量略有增加外,荒地和农田均持续下降。降水年型对土壤水分变异系数的影响表现为枯水年>平水年>丰水年,其中荒地土壤水分变化最为剧烈,表现在枯水年出现了速变层,而在丰水分内次活跃层也较农田向土壤深层延伸,其次为农田和裸地。

松嫩高平原黑土区耕地资源安全的驱动机制分析

为了深入剖析影响区域耕地资源安全驱动因子的作用机理,研究区域耕地资源安全驱动机制。该文以松嫩高平原黑土区巴彦县为例,运用Matlab编程,采用遗传算法对神经网络模型进行改进,结合相关分析法,识别影响耕地资源安全的关键性因子及其与之相关的因子,应用多元回归分析和完全二次回归分析方法,阐明影响因子间的协同作用关系,进而揭示其对耕地资源安全影响的作用机理和驱动机制。结果表明:1)影响研究区耕地资源安全的协同作用关系中,不同影响因子间的协同作用正向和负向交互进行,且不同因子间协同作用大小也不尽相同;2)影响研究区耕地资源安全的自然因素、社会经济因素、生态因素中,自然因素对研究区耕地资源安全起促进作用,社会经济因素和生态因素起抑制作用,且社会经济因素对研究区耕地资源安全的抑制作用最强,生态因素的抑制作用次之;3)在主要影响因子中,土壤质地对耕地资源安全的促进作用最强,pH值次之,黑土层厚度的促进作用最弱,而高程对耕地资源安全抑制作用最强,水土流失量仅次之,氟的抑制作用最弱。该研究成果可为黑土区耕地资源保护及耕地资源的合理利用提供参考。

黄土丘陵区退耕还林(草)土壤环境效应

通过采样与分析,研究了上黄试区不同土地利用类型、不同坡地植被恢复措施及不同植被恢复年限的土壤养分状况,结果表明坡耕地土壤存在不同程度的退化现象,土壤养分,有机质含量较低;坡耕地与不同恢复措施的林地草地相比,速效K、速效N及有机质含量低,pH值则偏高;坡耕地退耕还林还草年限越长土壤改良效益越明显。

黑土区耕地地力综合评价研究

耕地地力的变化对粮食生产、生产力等具有重要的影响,黑土是东北地区重要的土壤资源,黑土耕地面积占东北区总耕地面积的18 08%,但常年粮食总产量占全区粮食总产量的28 1%,占全国粮食总产量的7 8%,具有十分重要的地位[1],但是由于掠夺式的经营,导致黑土不断退化。在分析了德惠市耕地地力等级评价因子的基础上,利用RS和GIS建立了耕地资源数据库,确定了每个评价因子的权重,并利用层次分析法,进行耕地地力的评价,最后利用耕地地力综合评价等级指数确定耕地的级别,为黑土区耕地退化治理和耕地的可持续利用与管理提供决策依据。图1,表1,参9。

黑土区土壤侵蚀与土地利用关系分析——以黑龙江省克山县为例

应用TM遥感影像,提取土地利用和土壤侵蚀的相关信息。采用叠加分析的方法,对黑龙江省克山县1995-2000年的土地利用变化和土壤侵蚀变化的关系进行了分析。结果表明:黑龙江省克山县土地利用的变化不利于水土保持、土壤侵蚀面积的减少以及土壤侵蚀强度的降低,影响土壤侵蚀的主要土地利用变化发生在微丘平原区旱地。