Alley cropping rice (Oryza sativa var.Barafita) with cassia (Cassia siamea): soil fertility and crop production

Rice grain weight and quality (weight of larger size fractions), soil pH, and N, P, K and organic matter content were studied where rice was alley cropped with cassia on a semiarid site in The Gambia. The four treatments, control (no cassia prunings or inorganic fertilizer added), only prunings added, prunings plus half the recommended fertilizer rate and prunings plus full recommended rate of fertilizer, were applied in a Latin square design with 10×8 m plots, each sub-divided into two 4-m wide alleys. Fertilizer was applied twice; full rates were 93.7 kg/ha NPK (8:24:24) plus 32.4 kg/ha urea followed two weeks later by 100 kg/ha urea applied as side dressing. Soil samples collected before and after cropping at 0–10 cm and 10–15 cm depths and cassia pruning samples were analyzed for pH, N, P, K and organic matter content.Our results do not show significant benefit of cassia prunings applied as mulch to grain weight or quality in alley cropping rice with cassia. The addition of inorganic fertilizer plus cassia prunings did not increase rice grain and straw weights (p=0.3447 and p=0.0691, respectively) compared to the control and prunings only treatments. In all treatments, the outer rows, those within 80 cm of hedgerows, produced significantly less grain (p=0.0002) and straw than inner rows. Neither the larger grade A nor the smaller grade B grain weights were significantly different (p=0.6017 and p=0.0629, respectively) between treatments. Weight of grain, straw, and larger grade A and smaller grade B quality grain did not differ significantly for inner and outer rows (p=0.6329, p=0.7148, p=0.7171 and p=1.000, respectively).     

管理风险多维度量模型的建立与检验

分析多维风险度量模型中影响风险的因素间的逻辑关系,构建了可管理风险的多维度量模型,然后应用BP神经网络对该模型进行检验。检验结果表明该模型能够对可管理的风险进行度量。     

Dietary shifts in the crystal darter (Crystallaria asprella) after large-scale river fragmentation

Abstract –  The crystal darter, Crystallaria asprella (Jordan), is a benthic, riverine specialist, rare throughout its range and critically imperiled in the state of Mississippi. Construction of the Tennessee–Tombigbee Waterway has fragmented a once continuous population of this species into several subpopulations in remaining, free-flowing tributaries of the system. In spite of this fragmentation and population subdivision, we collected numerous individuals from the waterway during summer 2004 and 2005. Because of the lentic conditions in the waterway, we questioned whether a dietary shift accompanied darters occupying this new environment. We also obtained museum specimens from the Tombigbee River before waterway construction and quantified and compared diets among the historical, tributary (contemporary) and waterway specimens. We hypothesised that waterway specimens would differ significantly in diet from both historical and tributary specimens, and that the latter two groups would have similar diets. Multiresponse permutation procedures indicated that all three groups were significantly different from each other and indicator species analysis identified significant indicator taxa for waterway and tributary specimens. Using a null model approach, dietary overlap was significantly greater than expected for tributary and waterway specimens, and significantly less than expected for waterway and historical specimens. Dietary plasticity was evident for crystal darters across space and time, but it remains unknown whether waterway individuals represent a population sink or are actively dispersing from nearby population sources.     

基于多维空间变异分析的精确农业作业单元自适应决策

针对精确农业技术体系中最佳农艺作业单元大小,该文提出了一种用纵、横探测法推求土壤特性空间变异、作物长势空间变异以及前茬作物产量空间变异等多维空间变异指数,进而按一定农学原则决定最佳农艺作业单元尺寸的自适应解决方案。结果表明,用该算法确定的农艺作业单元尺寸进行变量施肥,平衡效果良好率在90%以上。该算法的另一特点是,对矢量和栅格数据具有同样的适用性,较易在矢栅混合型GIS上实现。     

多维贫困的空间聚类与相关性研究

区域多维贫困是2020年后我国减贫事业的重要导向,也是减贫理论研究的重要内容。基于2010、2012、2014、2016、2018年全国31个省市自治区的相关数据,运用主成分分析、系统聚类分析和Moran’sI指数分析的方法研究了各省际区域多维贫困的空间聚类情况及其相关性,以此来分析我国各地区多维贫困的空间特征和区域差别。结果表明:我国各个地区的多维贫困存在程度上的差异,其中北京等地区已逐步脱离多维贫困,西藏等地区存在严重的多维贫困问题,其余地区则呈现不同程度上的多维贫困。同时,各地区的多维贫困存在地理上的空间自相关。在此基础上,提出空间性的多维贫困治理的建议。     

基于模糊综合模型的商业地产多维定位研究

商业地产项目定位是房地产经济管理中的一个重要课题,为了科学地量化定位指标,通过构建多维定位矩阵详细描述指标体系,并且运用模糊数学方法和建立多层模糊综合评判模型,把模糊性很强的商业地产评价指标量化,证明模糊综合模型有助于对拟定方案进行筛选,选择最合适的商业地产定位方案.     

文献研究者的创维思维:以元人钟嗣成《录鬼簿》为认识对象

新时期钟嗣成《录鬼簿》的研究,出现多元化。研究者运用创维思维方式得出新颖结论,此书的结构具有"史"的线索;"以人类书"及其"因书见人",著录剧目而具有目录学价值;"人有评传""剧有批评"创戏剧学模式;序和吊词乃创作又是感伤诗篇,是一部立体的、多功能意义的曲学著作,具有丰富的曲学知识内涵,其应用价值大于此书的性质研究。     

Woodland trees modulate soil resources and conserve fungal diversity in fragmented landscapes

Resource islands around woody plants are thought to define the structure and function of many semiarid and arid ecosystems, but their role in patterning of soil microbial communities remains largely unexamined in dry environments. This study examined soil resource distribution and associated fungal communities in two Allocasuarina luehmannii (buloke) remnants of semiarid north-western Victoria, Australia. These savannah-like woodlands are listed as endangered due to extensive clearing for agriculture. We used the DNA-based profiling technique T-RFLP and ordination-based statistical methods to compare fungal community compositions in surface soils from two remnants (located 1.6 km apart) and three sampling positions (beneath individual buloke canopies; grassy inter-canopy areas; and adjoining cleared paddocks). Resource island formation beneath buloke trees was clearly evident in soil physicochemical properties (e.g. threefold concentrations of total carbon and nitrogen in canopy versus non-canopy soils). This heterogeneity of resources was moderately correlated with soil fungal community compositions, which were distinct for each sampling position. We argue that fungal composition patterns reflected multiple roles of fungi in dryland ecosystems, namely: responses of saprotrophic fungi to tree organic matter inputs; specificity of ectomycorrhizal fungi to tree rooting zones; and fungal involvement in biological soil crusts that variably covered non-canopy soils. Our data did not indicate that buloke canopy areas were particular hotspots of soil fungal diversity, but that they increased landscape-level diversity by supporting a distinct suite of fungi. In addition, we provide evidence of phylogenetic differentiation of soil fungal communities between our two remnants, which adds to growing evidence of fungal genetic structure at localised scales. These findings highlight the importance of remnant trees in conserving both soil resources and microbial genetic diversity. In addition, evidence of differentiation of soil fungal phylogenetics between nearby but isolated remnants suggests that conserving soil fungal diversity requires conservation of host habitats over their entire (remaining) range, and indicates previously unseen consequences of tree loss from extensively cleared landscapes.     

云南边疆少数民族地区村域多维贫困测度及空间分异研究

边疆少数民族地区的农村贫困治理一直是脱贫攻坚战略中最难啃的"硬骨头",揭示村域农村多维贫困时空分异规律,对于促进边疆少数民族地区农民脱贫增收具有重要意义。该文以云南省镇沅县为研究对象,在构建村域多维贫困测度指标体系的基础上,运用多维贫困测度模型、Moran指数、地理探测器模型等方法,对镇沅县109个村的多维贫困程度、空间格局以及主导因素进行研究。结果表明:镇沅县村域多维贫困程度较高,有55个村处于高贫困水平,空间格局表现为"东西高、南北次高、中心低"的结构特征,即贫困程度较高的村集中于东部的哀牢山区和西部、北部的无量山区,贫困程度较低的村主要集中于以县城为中心的恩乐镇、按板镇东部和古城镇北部地区;空间关联格局研究表明,镇沅县村域多维贫困空间上存在着显著的集聚特征,集聚的低值中心主要分布在中部恩乐镇和按板镇,集聚的高值中心主要分布在西部的振太镇;影响镇沅县村域多维贫困空间分异的主导因素包括人均耕地面积、25°坡度以上耕地面积比例、有无出村公交线路、到县政府驻地车程时间、农药使用强度、地质灾害强度、土地流转面积比例、贫困人口比例、年人均纯收入等。地方政府应该根据区域优势资源,制定合理且有针对性的扶贫策略。     

妇女多维贫困测量、分解与精准扶贫——基于福建省“巾帼扶贫”五年攻坚计划调研数据

为了解妇女多维贫困度,采用MPI指数的A-F方法,利用2015年福建省妇联"巾帼扶贫"五年攻坚计划专项调研数据,从11个维度对贫困妇女进行多维贫困测量,并对多维贫困指数进行分解。结果表明:福建省贫困妇女最为严重的贫困状况为9个维度同时存在贫困现象。社会关系、健康、教育、卫生设施、决策权这些维度对福建省贫困妇女多维贫困的贡献率较高。龙岩、泉州、漳州、南平等地区在不同维度取值下分别显示贫困贡献率较大。