Spatiotemporal Pattern of Cultivated Land Pressure and Its Influencing Factors in the Huaihai Economic Zone, China

Cultivated land pressure represents a direct reflection of grain security. Existing relevant studies rarely approached the spatiotemporal pattern of cultivated land pressure or the spatial heterogeneity of its influencing factors from the level of economic zones.Taking the Huaihai Economic Zone(HEZ), China for case analysis, this study investigated the spatiotemporal pattern of cultivated land pressure in diverse periods from 2000 to 2018 based on a modified cultivated land pressure index and spatial correlation models. On this basis, it explored the influencing factors of the spatial differentiation of cultivated land pressure in the late stage of the study using geographical detector as well as multi-scale geographically weighted regression model. The results indicated that: 1) in the study period, the global cultivated land pressure index of the study area decreased gradually, but cultivated land pressure increased locally in a significant way, especially in the central and southern Shandong Province;2) the spatial pattern of cultivated land pressure manifested global clustering features. Hot and secondary-hot spots presented a narrowing and clustering trend, whereas cold and secondary-cold spots manifested a spreading and clustering trend;3) average slope, the proportion of non-grain crops, population urbanization rate, and multiple cropping index have significant effects on the spatial differentiation of cultivated land pressure. The former three factors were positively correlated with cultivated land pressure, and the last factor was negatively correlated with cultivated land pressure;and 4) the amount of cultivated land has increased in the central and southern Shandong Province through land consolidation which, nonetheless, failed to improve the grain production. In regards to major grain producing areas similar to the HEZ in China, the authors suggest that great importance should be given to the balance of the quality and quantity of cultivated land, the optimization of agricultural production factors and the rational control of non-grain crops, thus providing a powerful guarantee for grain security in China.

CUMULATIVE EFFECTS OF DIFFERENT CULTIVATING PATTERNS ON PROPERTIES OF ALBIC SOIL IN SANJIANG PLAIN

This paper studied the cumulative effects of different cultivating patterns on the properties of albic soils in the Sanjiang Plain using correlation analysis. The results showed that the physical and chemical properties of the albic soil changed greatly when it was cultivated as farmland. As for physical properties of the soil, bulk density and specific gravity increased gradually, the porosity and field capacity decreased gradually year by year, but they increased after being abandoned. As for chemical properties, pH increased, organic matter and other nutrients decreased with increasing of the cultivating years. For the albic soil cultivated with forage, the cumulative effects were apparently strengthened with the increase of cultivating years, especially for the bulk density, total porosity, capillary porosity and capillary moisture capacity. Moreover, fertilization also had great effects on the albic soil. Applying magnetism ferti- lizer improved the physical properties such as bulk density, soil moisture and porosity, raised the utilization rate of nitrogen and phosphorus fertilizer. Compared with nutrient fertilizer, utilization of the magnetism fertilizer made production increase by 5.9%-13.9%. At the same time, using organic material and loosing the albic layer could improve not only the physical, chemical and biological properties of the cultivating layer, but also the ill properties of the albic layer, thus making organic carbon and heavy fraction carbon contents increase, and biological activity increase obviously.

Spatial patterns of farmland abandonment and its impact factors in the central Three Gorges Reservoir Area

The severe farmland abandonment phenomena in China have tremendously decreased the farmland usage efficiency and caused a series of profound ecological and social outcomes. The complexity of farmland abandonment necessitates a systematic research on its patterns and impact factors to underpin the dynamics of problem as well as potential solutions. This paper took Wanzhou district in the central part of Three Gorges Reservoir Area as an example to study the spatial distribution patterns of abandoned farmland at three scales, i.e., town, village, and plot, and analyzed the influence from labor transfer and farmland circulation. We conducted a survey on the distribution patterns of abandoned farmland via questionnaires at town and village scales, together with the modeling and interpretation of high-resolution aerial images taken by unmanned aerial vehicles at plot scale. Our research discloses a strong relationship between the distribution of abandoned farmland and the distance from population center at different scales. At eithertown or village scale, the abandonment proportion was recognized the highest in mid-distance areas and lowest in close-distance areas, and the per capita area of abandoned farmland increased with the distance to downtown or township. At plot scale, abandonment proportion presented exponential growth with the distance to village center, whereas the abandoned farmland was mainly distributed in the areas with distance above 500 m from the village center. Moreover, we noticed that labor transfer and farmland circulation are two important factors that influence farmland abandonment. Labor's outbound transfer distance has a positive linkage with the possibility of farmland abandonment. Finally, it is recommended that development and adoption of corresponding policies on local urbanization and farmland circulation will facilitate to alleviate farmland abandonment.

Analysis of Patterns and Benefits of Cultivated Land Transfer in Rural Areas in the Loess Plateau——A Case Study of Yuanzhou District of Ningxia

Cultivated land transfer is one of hotspots in research on agriculture,rural areas and farmers in China. Based on research achievements related to cultivated land transfer and the field survey of Yuanzhou District in the Loess Plateau,the primary patterns of cultivated land transfer in rural areas in the Loess Plateau were summarized according to the management subjects of cultivated land. According to the analyses of family income and expenses of a peasant household,the benefit of various patterns of cultivated land transfer to increase farmers' income was analyzed,and the social and ecological benefits of cultivated land transfer were assessed. The results showed that cultivated land transfer had developed rapidly in the Loess Plateau,and 42. 5% of the investigated peasant households took part in cultivated land transfer. The benefit of cultivated land transfer to increase farmers' income was obvious after cultivated land transfer. There were significant differences between various patterns of cultivated land transfer in the increase of farmers' income. The pattern driven by agricultural cooperatives increased farmers' income most obviously,and the annual family earnings per peasant household reached 12072. 99 yuan / a. The social and ecological benefits of cultivated land transfer conducted by peasant households spontaneously were very remarkable. The pattern led by leading enterprises promoted the large-scale operation of cultivated land greatly,but its benefit to increase farmers' income was limited. The comprehensive benefit of the pattern guided by the government was the most balanced. Geographic environment had decisive influences on the choose of patterns of cultivated land transfer in the Loess Plateau.

Study on the Characteristics and Efficient Cultivation Techniques of "Rice-Rice-Potato" Triple Cropping Rotation Pattern

The efficient cultivation technique of "rice-rice-potato" triple cropping rotation pattern is summarized by analyzing its characteristics and cultivation techniques in Yangjiang region of Guangdong Province,China,and machine-transplanted cultivation technique of double cropping rice and cultivation techniques of winter potato black film mulching are emphatically introduced,in order to promote the development of potato industry in Yangjiang City.The results will provide a scientific basis for the popularization and application of the "rice-rice-potato" triple cropping rotation pattern.

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.

2000—2020年非洲耕地资源时空格局变化分析

非洲地区面临严重的粮食安全问题,研究其耕地资源时空格局变化对于保障非洲粮食安全具有重要意义.基于2000—2020年间联合国粮农组织的统计数据,通过重心迁移、标准差椭圆及局部空间自相关等方法对非洲耕地资源时空格局的变化特征进行了分析.结果表明:1)非洲耕地整体数量呈稳定上升趋势,20年间耕地面积增加了6321.92万hm^(2),增长率为53.44%,但不同国家间存在差异;2)非洲耕地在几何中心以北区域分布较多,耕地重心迁移方向先向东北后转向偏西方向,移动总距离为111.86 km,偏移速率先快后慢,从前5年的平均10.27 km/a降至后15年的平均4.00 km/a左右;3)非洲耕地分布呈西北—东南向,20年来标准差椭圆转角有向水平方向倒伏趋势,椭圆面积不断缩小,向心性不断增强;4)非洲耕地分布集聚主要出现在西非的尼日尔和尼日利亚,异常区为南非及贝宁.

东北三省耕地利用格局变化对粮食全要素生产率的影响

耕地是粮食生产最基本的要素,当前粮食需求扩大与粮食生产区域性不足矛盾突出,寻求更合理的耕地利用格局来实现粮食全要素生产率的提升具有重要意义。本研究基于土地利用/土地覆被变化(LUCC)遥感监测数据,应用GIS软件提取东北三省2000、2005、2010、2015年耕地利用格局相关数据,同时运用数据包络分析模型估算了2000、2005、2010年和2015年东北三省区域和市域粮食全要素生产率。在耕地利用格局变化分析和粮食全要素生产率测算的基础上,从耕地利用格局变化的角度选取指标构建面板数据模型,定量分析其对粮食全要素生产率的影响。结果表明:东北三省市域粮食全要素生产率4个时期均值分别为0.81、0.78、0.82和0.83,粮食全要素生产率空间分布从最初的相对均匀到局部集聚;耕地转出率和耕地斑块破碎度与粮食全要素生产率呈负相关关系,耕地面积比例、耕地转入率和耕地斑块聚合度与粮食全要素生产率呈正相关关系;东北三省粮食全要素生产率提高主要源于耕地面积增加、林地和未利用地向耕地的转入以及耕地在流域的聚合,粮食全要素生产率的降低主要源于耕地转入减少和建设用地对耕地的嵌入式占用。研究表明,严格规划耕地利用格局、持续开展土地整理、提高耕地聚合度,可在保证耕地有效数量的同时,提高耕地利用格局的集聚性和合理性,促进粮食全要素生产率的提升。

以“学用互促”为特点的本科生新媒体素养培育模式研究——以浙江大学图书馆i-Lab学生创新工作室为例

文章聚焦本科生新媒体实用技能素养培育,基于教学支架、元素养、小组合作学习理论设计以“学用互促”为特点的培育模式,以浙江大学图书馆i-Lab学生创新工作室为依托,开展“分组制”量体裁衣、“系列课程+实践应用”穿插结合、“老带新”合作学习等实践探索,并提出国内高校推广实施建议,以期为新媒体环境下信息素养教育的开展注入新思路,推动素养培育与学生成长互融互促的良性循环,亦为学生团队培育提供参考。

基于景观指数的关中地区耕地细碎化程度的时空变迁及其驱动因素

[目的]优化陕西耕地细碎化治理,协调粮食需求增长与环境约束之间的矛盾,维护地区粮食安全和促进农业现代化发展。[方法]以关中地区为研究区,以土地利用数据和其他自然经济数据为基础,运用洛伦兹曲线、变异系数法、景观指数、空间自相关等方法构建耕地细碎化评价模型以探索关中地区耕地细碎化(Cultivated Land Fragmentation,简称CLF)的时空变迁,并利用地理探测器对区内CLF进行了驱动力分析。[结果](1)关中地区耕地资源空间分布相对均衡,耕地专业化程度保持较高水平。(2)关中地区的CLF程度变化时空差异显著,CLF程度整体呈现下降态势,但部分地区CLF程度呈增减并存趋势,整体呈现东低西高的态势。(3)关中地区CLF时空分化受多种因素影响,社会经济因素的综合影响明显强于自然因素,其中海拔高度、人口密度、人均耕地面积和地区总产值GDP为主要影响因素;因子间的交互作用效应强于单因子,以双因子增强和非线性增强为主。[结论]关中地区耕地细碎化问题在20年间得到了一定程度的改善,但呈现出较大的地区差异,应进一步在社会经济因素方面对耕地细碎化现象加强综合治理,以推动关中地区农业机械化、现代化发展。

基于动态稳定性验证和CA-Markov预测的耕地时空演变特征--以赣榆区为例

为阐明耕地变化动态稳定性验证的重要性,预测“十四五”目标年(2025年)与远景目标年(2035年)的耕地变化,本研究运用耕地面积变异系数、地理集中指数、不平衡指数及趋势分析法,从耕地数量、空间分布与空间发展趋势三个方面,对江苏省连云港市赣榆区耕地变化的动态稳定性进行验证,并运用CA-Markov模型对未来不同政策情境下的耕地变化情况进行模拟。结果表明,2009-2016年赣榆区耕地总量持续下降,未存在较大反复与波动,耕地空间分布较为均衡,耕地占用与补充的空间发展趋势较为连续,总体上具有较高的动态稳定性,符合运用CA-Markov模型的前提条件。预测在各种政策情境下,2025年之前赣榆区将经历快速的耕地非农化过程,至2035年耕地减少的速率有所放缓,具有区位优势的赣榆北部地区将是未来耕地非农化的重点区域,耕地将逐渐向南部内陆地区转移。研究表明,对耕地变化的动态稳定性进行验证可以有效保证CA-Markov模型的模拟精度,赣榆区未来的耕地保护形势不容乐观,应合理协调经济发展与耕地保护之间的关系,保障社会、生态与粮食安全。

“双碳”目标下东北黑土区耕地利用生态效率时空格局与演变趋势

[目的]探究东北黑土区耕地利用生态效率的时空格局和演变趋势,将碳源与碳汇融入耕地利用过程,这对于实现黑土减排增效和“双碳”目标至关重要。[方法]基于超效率SBM模型、核密度估计、探索性空间数据分析和空间插值工具等方法,系统考察了2006—2020年东北黑土区耕地利用生态效率的时空特征与演进规律。[结果]黑土区耕地利用生态效率历经波动上升、显著下降和迅速回升3个阶段,总体处于较高发展水平,北部边缘城市的效率值明显高于中南部地区,基期和末期区间两极分化局势尤为显著,整体发展严重失衡;黑土区耕地利用生态效率全局空间相关特性并不明显,大致呈现“边缘—中心”空间扩散格局,由南北两端高值集聚向内及四周递减,而后形成多个块状高值区和低值分布带,规模集聚优势未能得到充分发挥;多数城市均存在不同程度的投入与产出冗余,劳动力和化肥冗余问题较为严重,碳排放冗余是造成黑土区耕地利用生态效率损失的普遍因素。[结论]优化要素配置和污染减排治理成为黑土利用重点改善方向,也是提升黑土区耕地利用生态效率的关键路径。

谋开放新篇 育强国优师--《教育部关于实施国家优秀中小学教师培养计划的意见》解读

2023年7月教育部制定了国家优秀中小学教师培养计划(以下简称“国优计划”),旨在以“双一流”建设高校为依托,选拔培养专业成绩优秀且乐教适教的理工类学科人才,从而为基础教育事业培养和输送高质量的优秀教师。“国优计划”的出台,一方面是对教师教育历史政策实践,即推动教师教育向高质量发展模式转变,以及健全以开放、协同、联动为主要特点的现代教师教育体系的继承与延续;另一方面是为推动新时代教育强国、科技强国、人才强国建设和契合基础教育发展新形势所制定的创新发展路径,即构建多主体联动,贯通本研、职前职后一体化培养模式,实现“优秀人才”向“优秀教师”转化,切实解决教师队伍建设中存在的学科结构不均衡、培养层次不高等方面的问题,从源头上强化拔尖创新人才的培养。为此,对“国优计划”的政策实施路径提出以下建议:促进政策主体的外部行动协同与内部治理优化;规范研制人才选拔标准与培养方案;建立和健全面向政策实施的专业评估与跟踪监测机制;建立与政策相配套的培训与试点经验交流机制。

全国名中医贾英杰“黜浊培本”论治卵巢癌的经验撷英

卵巢癌是病死率最高的妇科恶性肿瘤。全国名中医贾英杰认为卵巢癌是虚实夹杂、本虚标实之证,其病位在卵巢,与肝、脾、肾三脏密切相关,发病的基本病机为脾肾亏虚、冲任失调、癌浊内蕴、客于虚处。治疗当以“黜浊培本”为基本原则。强调疏利三焦,尤重下焦;固本培元,脾肾同调;条达枢机,疏运相合;因势利导,血水同调;中西合参,分型论治。总结贾英杰教授治疗卵巢癌的中医临证经验,并附验案1则加以阐明。

鄱阳湖生态经济区建设用地扩张对耕地景观破碎化的影响

为分析鄱阳湖生态经济区耕地景观与建设用地扩张之间的关系,利用形态学空间格局分析法研究2000-2020年耕地景观破碎化的形态学特点,同时运用外溢效应分析、景观格局指数分析、地理加权回归等模型方法,探究建设用地扩张对耕地景观破碎化的影响。结果表明:2000-2020年间耕地景观破碎化程度加强,核心区面积减少强度由1.33%提高到6.27%,并表现出由平原地区向山地丘陵区加强的地域性差异,且建设用地扩张会导致耕地景观破碎化;建设用地占用耕地的面积由268.60 km2增加到1 003.26 km2,主要发生在路网成熟的地区;建设用地扩张对耕地的外溢效应逐渐增强,在路网成熟地区更显著;建设用地扩张对耕地景观破碎化有较强的正向影响,道路建设对这种影响有强化作用,同时,耕地景观破碎化表现出随道路缓冲距离的减小而加强的阶梯性差异。研究表明,耕地景观破碎化程度受地形和建设用地扩张的影响显著,耕地景观破碎化现象主要发生在地势起伏大或建设用地密集、路网成熟的地区。

土地流转视角下耕地“非粮化”时空格局演变及驱动因素

该研究对2009—2020年中国流转耕地“非粮化”的时空格局进行量化测度,利用Tobit模型、空间计量模型和工具变量法,从“人”“地”“钱”多视角探析流转耕地“非粮化”的驱动因素及其空间异质性。结果显示:①流转耕地“非粮化”具有阶段性和区域性,非粮食主产区的流转耕地“非粮化”是全国层面流转耕地“非粮化”加剧的主要原因。②土地流转是耕地“非粮化”的重要驱动因素。提高土地流转面积和将土地流转给生活型经营者,有利于抑制耕地“非粮化”发展,但土地流转租金上涨会难以避免地加剧耕地“非粮化”程度。③土地流转与耕地“非粮化”关系存在区域异质性。在粮食主产区,土地流转面积提高对流转耕地“非粮化”的抑制作用更强;在非粮食主产区,生产型农业经营者采取“非粮化”种植行为的倾向更强。因此,为应对流转耕地“非粮化”现象,应健全耕地保护补偿制度,对防止流转耕地“非粮化”目标完成好的地区给予奖补;重点规范非粮食主产区的工商资本流转土地行为,对农户粮食种植行为给予奖励;进一步推进粮食主产区的土地流转和整治工程,发展耕地适度规模化经营;完善农地流转交易平台,继续加强土地流转价格监控。

大球盖菇研究进展

大球盖菇(Stropharia rugoso-annulata)作为一种药食两用的食用菌,近年来在我国栽培面积不断扩大。文章综述了大球盖菇丰富的营养成分和生物活性物质,如多糖、蛋白质、氨基酸等,并探讨了这些成分对人体健康的促进作用。此外,文章还详细阐述了大球盖菇的栽培技术、加工工艺以及在食品、医药以及环境生态等领域的应用潜力。

林下不同栽培模式下三叶青叶片光合特性的比较

目的:探究林下不同栽培模式的三叶青生长和光合特性的差异规律。方法:设置一年生三叶青林下地栽和袋栽2种模式,测定不同栽培模式下三叶青藤叶生长性状和光合特性的相关指标。结果:林下袋栽三叶青的主要农艺性状要优于林下地栽。袋栽模式下三叶青主茎长是地栽的3.04倍,林下袋栽的节数是地栽的2.09倍;林下袋栽模式下叶片的SPAD值和含氮量均显著高于地栽模式;2种模式下的光合指标之间变化趋势不尽相同,袋栽模式下叶片净光合速率、瞬时水分利用率、光合有效辐和叶面温度等指标均显著高于地栽模式;各个指标相关性分析表明三叶青的净光合速率与叶面温度呈显著正相关;光合有效辐射与SPAD值、叶片氮含量呈极显著正相关,与叶面温度呈显著正相关,而与主茎长和节数呈显著负相关。结论:林下袋栽模式下三叶青的生长和光合性能显著优于林下地栽,可为三叶青人工种植模式提供参考。

基于景观格局的丘陵山区耕地生态风险评价——以重庆市潼南区为例

[目的/意义]丘陵山区农田宜机化整治会改变耕地景观格局、高程、坡度、微地貌等,评价其生态风险为后续整治工作提供数据参考具有重要意义。本研究的目的为评价丘陵山区农田宜机化整治对耕地生态风险的改变情况以及探究生态风险与耕地坡度之间的关系。[方法]以重庆市潼南区20个县为评价单元,基于2010年和2020年土地利用数据,采用ArcGIS 10.8和Excel软件计算景观格局指数,通过熵权法确定各指数的权重并构建生态风险评价模型,揭示生态风险时序空间变化特征;基于数理统计原理,对生态风险与坡度进行相关性分析,探究生态风险与坡度的关系。[结果和讨论] 2010年和2020年两个时期,干扰度指数由0.97下降为0.94,耕地整体抗干扰能力增强;脆弱度指数由2.96增加为3.20,耕地结构更加脆弱;生态风险值由3.10下降为3.01,耕地生态安全性提高。两个时期生态风险区域主要以低风险区和较低风险区为主,低风险区面积增加6.44%,较低风险区面积增加6.17%,中风险区面积增加24.4%,较高风险区面积减少60.70%,高风险区面积增加16.30%,耕地生态安全区域相对增加。耕地坡度主要以2°~25°为主,耕地坡度小于15°时坡度面积占比与生态风险值呈负相关,耕地坡度大于15°时坡度面积占比与生态风险值呈正相关关系,坡度处于5°~8°、15°~25°、25°以上时坡度面积与生态风险值呈极显著相关。农田宜机化整治应重点关注潼南区南部区域,并集中于耕地坡度处于5°~8°和15°~25°区域。[结论]通过评价潼南区农田宜机化整治前后耕地生态风险并分析生态风险与耕地坡度的相关性,表明农田宜机化整治可以降低耕地生态风险,耕地坡度面积占比可作为精准指导农田宜机化整治的重要依据,潼南区宜机化整治工作应重点关注耕地坡度处于5°~8°和15°~25°区域。

以综合能力培养为目标的本科模式识别课程改革与探索

针对传统以单一教材结合PPT讲授为主的授课方式对模式识别课程表现不足的问题,文章主要从课程教学设计、教学资源建立以及课程考核机制三个方面进行课程改革与探索,通过理论与实践相结合的教学方式培养学生的学习能力、实践能力和创新能力。