小麦-玉米-大豆带状复合种植机械化研究进展

为实现目前在四川丘陵旱地大力推广的国家主推技术--"小麦-玉米-大豆"旱地新三熟带状复合种植模式的机械化生产,该文研究了复合种植作物的带宽配置和农艺措施,选择"100-100"带宽配置为该模式配套机械化的主体模式;分别运用微型、小型和中型动力机组进行了主体模式下的机械化作业、并针对该模式研发的玉米和大豆收获机进行试验。结果表明：带状复合机械化是可行的,以MINI小四轮拖拉机为动力的机具系统能满足主体模式和丘陵小地块的生产要求,具有良好的经济和社会效益,是发展四川丘陵旱地农业生产机械化的良好载体。     

小麦-玉米-大豆带状复合种植机械化研究进展

为实现目前在四川丘陵旱地大力推广的国家主推技术——"小麦-玉米-大豆"旱地新三熟带状复合种植模式的机械化生产,该文研究了复合种植作物的带宽配置和农艺措施,选择"100-100"带宽配置为该模式配套机械化的主体模式;分别运用微型、小型和中型动力机组进行了主体模式下的机械化作业,并针对该模式研发的玉米和大豆收获机进行试验。结果表明:带状复合机械化是可行的,以MINI小四轮拖拉机为动力的机具系统能满足主体模式和丘陵小地块的生产要求,具有良好的经济和社会效益,是发展四川丘陵旱地农业生产机械化的良好载体。     

小麦-玉米-大豆带状复合种植机械化研究进展

为实现目前在四川丘陵旱地大力推广的国家主推技术——"小麦-玉米-大豆"旱地新三熟带状复合种植模式的机械化生产,该文研究了复合种植作物的带宽配置和农艺措施,选择"100-100"带宽配置为该模式配套机械化的主体模式;分别运用微型、小型和中型动力机组进行了主体模式下的机械化作业,并针对该模式研发的玉米和大豆收获机进行试验。结果表明:带状复合机械化是可行的,以MINI小四轮拖拉机为动力的机具系统能满足主体模式和丘陵小地块的生产要求,具有良好的经济和社会效益,是发展四川丘陵旱地农业生产机械化的良好载体。     

1980-2017年孟加拉国城市扩张的景观格局变化特征及其模式

[目的] 对1980—2017年孟加拉国城市扩张的景观格局变化特征及其模式进行研究，为该国及发展中国家的城市土地利用与管理提供差异化发展建议。[方法] 以“一带一路”沿线孟加拉国的4个主要城市Dhaka，Chittagong，Khulna和Sylhet为研究对象，分析1980，1990，2000，2010和2017年5期4个城市扩张过程中的景观格局变化特征，识别城市扩张模式。[结果] 1980—2017年，孟加拉国4个主要城市的扩张规模表现为：Dhaka > Chittagong > Khulna > Sylhet，扩张速度表现为：Sylhet > Dhaka > Chittagong > Khulna；4个城市扩张的景观格局变化趋势均表现为面积持续增加，优势度加强，破碎化程度波动上升。空间格局向复杂化和不规则化方向发展，空间形态逐渐多样化。1980—1990年，Dhaka，Chittagong和Sylhet这3个城市扩张的主要模式为外部扩张式，Khulna主要为邻接扩张式，1990—2017年，邻接扩张式成为4个城市扩张的主要模式，城市连片度逐渐增高。[结论] 1980年以来，孟加拉国城市持续扩张，景观格局发生显著变化，扩张模式总体呈由外部扩张式向邻接扩张式转变的趋势。     

泥质海岸盐碱地刺槐-杨树混交林改土效果研究

在北方泥质海岸盐碱地采用工程整地措施修筑台田,于台田上布置刺槐纯林、杨树纯林、刺槐—杨树混交林3种树种配置模式,对混交林及纯林的降盐改土效果进行研究。结果表明,11a后3种林分类型基本郁闭,保存率为63%～72%,郁闭度为0.6～0.7。混交林的树高、胸径优于纯林。3种模式脱盐作用范围在0—70cm土层;在50—70cm这一土层形成了养分亏缺层。混交林可提高林地土壤有机质含量;0—100cm全氮含量的土壤剖面分布规律与有机质相似,3种模式土壤全磷含量变幅不大,总体表现为磷素总量不足,有效性低。因子分析表明刺槐—杨树混交林降盐改土效果好于杨树纯林,也好于刺槐纯林,能够改善泥质海岸盐碱地土壤肥力状况,可作为一项成功的造林模式进行推广应用。     

草-牧-沼-果循环模式与长汀水土保持实践

以种草为基础,沼气为纽带,果业、畜牧业为主体,设计出草-牧-沼-果为核心的生态农业模式。寻找生态效益与经济效益的结合点,探讨了侵蚀地生态重建的思路与实施方案,最后对示范区建设的生态、社会和经济效益进行了分析。     

“猪-沼-果”水土保持综合治理模式简析

 “猪—沼—果”工程是20世纪90年代以来江西省赣南等水土流失严重地区综合治理水土流失的一种新模式,对巩固和促进治理成果取得了积极有效的作用。通过介绍“猪—沼—果”综合治理模式的内涵及“猪—沼—果”产业循环生态链,对“猪—沼—果”综合治理模式在小流域治理中的作用和效益进行全面阐述。其作用主要表现在3个方面:1)缓解能源紧缺的矛盾,保护自然植被,巩固治理成果;2)提供有机肥料,改善水土流失地土壤养分条件,促进开发性治理;3)促进小流域经济的发展,加快脱贫致富的步伐。同时,取得了显著的水土保持效益、生态效益和经济效益。     

闽东南果-草-牧-菌-沼生态农业模式研究

研究表明闽东南低丘台地实施的果-草-牧-菌-沼生态农业模式经济、生态和社会效益显著,年均纯收入37758.3元/hm2,且提高土壤含水量8.80%~20.07%,增加土壤有机质6.86%,夏、秋季地表温度降低11.3~19.6℃。     

鸡γ-干扰素cDNA的克隆和在大肠杆菌中的温度诱导型表达

克隆了鸡(Gallus gallus)的γ-干扰素cDNA，并用大肠杆菌(Escherichia coli)进行了温度诱导型表达。用PCR方法扩增了鸡γ-干扰素基因组基因，将其克隆到载体pGEM-T上。对重组载体的插入片段进行酶切分析和部分序列测定：证明了基因的正确性；克隆的鸡γ-干扰素基因的编码序列中存在一个点突变(G→A)，这一突变导致一个三联体密码子GAA变为AAA，编码的氨基酸由谷氨酸(Glu)变为赖氨酸(Lys)。用鸡γ-干扰素基因组基因构建了真核表达载体pCI-ChIFN。将这一真核表达载体转染兔成纤维细胞的细胞系中进行表达实验：提取转染后细胞裂解物中的RNA，再以此为模板进行RT—PCR，获得了完整的鸡γ-干扰素cDNA基因，同时证明鸡γ-干扰素基因组基因能在兔成纤维细胞系中表达。用鸡γ-干扰素cDNA构建了温度诱导型原核表达载体pBVcDNA，并将其转导到大肠杆菌DH5α中，经细菌发酵和温度诱导，表达了一个18kD的特异蛋白，其表达量占细菌总蛋白的8．75％。     

浙江省城镇化与生态-经济-环境耦合发展与动态计量

[目的]研究2000—2014年浙江省城镇—环境协调发展的动态计量特征,为浙江省制定新型城镇化可持续发展政策提供决策依据。[方法]基于耦合协调度模型,评价城镇化和生态环境的相互影响程度,并将其划分为4种类型,研究了城镇化和生态环境的协调关系。[结果](1)经济、社会、人口城镇化及其综合发展水平和生态环境响应、状态、压力及其综合发展水平均持续增长;协调度稳定增长,由低度协调发展为良好协调、城镇化滞后转变为生态环境滞后。(2)城镇化和生态环境的协调关系可划分为4种类型:良好协调—生态环境滞后、中度协调—生态环境滞后、良好协调—城镇化滞后、中度协调—城镇化滞后。[结论]各城市必须对应各自协调与滞后的现状,做到在保护生态环境的同时,继续加强城镇化建设,以推动二者协同发展。     

Semiparametric Kernel-Based Regression for Evaluating Interaction Between Pathway Effect and Covariate

Pathway-based analysis has the ability to detect subtle changes in response variables that could be missed when using gene-based analysis. Since genes interact with other covariates such as environmental or clinical variables, so do pathways, which are sets of genes that serve particular cellular or physiological functions. However, since pathways are sets of genes and since environmental or clinical variables do not have parametric relationships with response variables, it is difficult to model unknown interaction terms between high-dimensional variables and low-dimensional variables as environmental or clinical variables. In this paper, we propose a semiparametric interaction model for two unknown functions to evaluate the interaction between a pathway and environmental or clinical variable: for the pathway, we use an unknown high-dimensional function, and for environmental or clinical variable, we use an unknown low-dimensional function. We model the environmental or clinical variable nonparametrically via a natural cubic spline. We model both the pathway effect and the interaction between the pathway and environmental or clinical effect nonparametrically via a kernel machine. Since both interactions among genes within the same pathway and the interaction between the pathway and the environmental or clinical variables are complex, we allow for the possibility that a pathway is interacting with environmental or clinical variables and the genes within the same pathway are interacting with each other. We illustrate our approach using simulated data and genetic pathway data for type II diabetes. Supplementary materials accompanying this paper appear online.     

GIS支持的绿色食品产地环境质量预警系统研究——以黑龙江省庆安县国家级生态农业示范区为例

采用马尔可夫链模型预测未来5年环境质量状态发生概率,对国家级生态农业示范区庆安县绿色食品产地进行环境质量负向演化和恶化速度预警分析结果表明,该研究区内巨宝村、东阳村和泥河农场环境质量发出负向演化预警信号,而金星村、红星村、建业村、建民村、双利村和东阳村环境质量恶化速度最快。并提出排警对策。     

Integrated assessment of emission control scenarios,including the impact of tropospheric ozone

The RAINS (Regional Air Pollution INformation and Simulation) model was developed at IIASA as an integrated assessment tool to assist policy advisors in evaluating options for reducing acid rain. In recent years, the European implementation of this model has been used to support the negotiations on an updated, effect-based Sulphur Protocol under the Convention on Long-range Transboundary Air Pollution. The development of future strategies for reducing the environmental damage caused by air pollutants requires a multi-pollutant, multi-effect approach. In this context, the RAINS model is being further developed to include ozone. This paper outlines the development of an integrated assessment model for tropospheric ozone, which combines information on the emissions of ozone precursors (NO_x and VOCs), the available control technologies and abatement costs, the formation and transport of ozone and its environmental effects in Europe.     

Insecticide Residues in Eggplant Fruits, Soil, and Water in the Largest Eggplant-Producing Area in the Philippines

A multiphase model based on the Mackay-type level II fugacity model has been used to predict the behaviour and final environmental concentrations of some of the more consumed pharmaceuticals in Spain. The model takes into account the mean rate of consumption of pharmaceuticals, the percentage of pharmaceutical metabolised, the formation of the corresponding glucuronide, which is assumed to be hydrolysed back to the parent molecule, the partial degradation of each pharmaceutical in a conventional sewage treatment plant, and the fate of these substances in a regional model environmental system. Predicted environmental concentrations in air, water, soil, sediments and suspended matter, and the corresponding residence time for each pharmaceutical have been obtained by application of the model. The predicted concentrations of pharmaceuticals in the water phase are of the same order than the measured experimentally, showing that the simple model used to predict the environmental concentrations is suitable for modelling the environmental fate of high water soluble and low volatile organic compounds such as pharmaceuticals products.     

Testing,improvement, and confirmation of a watershed model of acid-base chemistry

Strategies to control the emission of atmospheric pollutants such as sulfur and nitrogen, are generally based in large part on projections using models that simulate the influence of sulfur and/or nitrogen deposition on the acid-base chemistry of surface waters. One of the principal models used throughout Europe and North America for such assessment is the Model of Acidification of Groundwater in Catchments (MAGIC). All watershed models are simplified representations of reality, and as such require careful testing to establish their veracity prior to use for making policy projections. This is particularly true where the use of these model projections has the potential for serious environmental or economic consequences. During the past five years, we have tested the MAGIC model in a large variety of settings and under quite varying environmental conditions. This work has included comparing model hindcast simulations with diatom-inferences of historical acidification, sensitivity analyses to examine the response of the model to alternative assumptions and formulations, and detailed testing of model forecasts by comparing simulated chemistry with the results of catchment-scale and plot-scale experimental acidification and deacidification. Our analyses have elucidated a number of potentially-important deficiencies in model structure and method of application. These have resulted in changes to the model and its calibration procedures. Our work has included in-depth evaluation of issues related to regional aggregation of soils data, background sulfur deposition, natural organic acidity, and aluminum mobilization. The result has been an improved and more thoroughly-tested version of MAGIC. The process we have followed to improve and confirm the MAGIC model has been iterative and time consuming. It required the availability of large volumes of data from experimental manipulation and paleolimnological studies. We believe that such model testing and confirmation efforts should be a critical prerequisite for regional or national assessment activities that are based largely on the results of environmental models.     

Almond organophosphate and pyrethroid use in the San Joaquin Valley and their associated environmental risk

Purpose

The purpose of the present study are to analyze the temporal and spatial trends of the pesticide use on almond crops and assess their associated risk to soil, surface water, and air, and to investigate the impacts of pesticide risk on biodiversity.

Materials and methods

California Pesticide Use Report database was used to determine the organophosphate (OP) and pyrethroid use trends in the San Joaquin Valley for almonds from 1992 to 2005. Environmental potential risk indicator for pesticides model was employed to evaluate associated environmental relative risks in soil and in surface water. Emission potential of pesticide product was used to estimate the air relative risk. Geographical Information System was used to delineate the spatial distribution patterns of environmental risk evaluation in almonds and biodiversity.

Results and discussion

OP pesticide use has been declined in any measurement in almonds. However, a converse result was found for pyrethroid pesticide. Pesticide use trends reflect the profound changes in pest management strategies in the California almond farm community. The model results in this study showed evidence that pyrethroid posed less environmental risks to soil, air, and water resources than OP. The physiochemical properties of pyrethroid reflect a strong tendency to adsorb to organic carbons, and therefore, potentially move off-site attached to sediment. Once in sediments, they can be bioavailable to the aquatic food web. So, more future study on environmental model should address pyrethroid environmental risk on sediment. Ecologists revealed that endangered species diversity has good correlation with total species diversity, so we developed a biodiversity index by using the survey data of endangered and rare animals in California. The results showed a negative relationship between count of animal occurrence and predicted environmental risk. This result would be useful to help conserve California??s biological diversity by providing information to promote agricultural management and land-use decisions.

Conclusions

Pesticide use trend is directly related to environmental risk. Pyrethroid posed less environmental risk than OP in this study. And also, this study got a noticeable result that pesticide uses in intensive agriculture and their associated environmental risks pose negative impacts on biodiversity.     

山区产业生态系统适应性与资源环境承载力的时空耦合协调关系——以秦巴山区81个区县为例

为了揭示秦巴山区产业生态系统适应性与资源环境承载力之间的耦合协调关系,基于P-S-R模型、熵权-TOPSIS模型、Pearson相关性指数及耦合协调度模型分析秦巴山区县域2010—2019年产业生态系统适应性及资源环境承载力的时空格局特征,并对两者的相关性及耦合协调关系进行了时空分析。结果表明:(1)山区产业生态系统适应性随时间呈现出先增后降的波动趋势,空间上为整体均匀分布,高值区散点迸发、局部锐减,低值区部分集聚。(2)山区资源环境承载力在时间尺度上先急速上升后缓步下降,在空间尺度上呈现出较为明显的“凹”字型空间结构。(3)山区产业生态系统适应性与资源环境承载力存在较高的相关性但随时间下降; 二者的耦合协调度逐渐提升,空间上表现为“散点初级协调”到“边缘初级协调”的西北向“口袋”型分布态势。秦巴山区产业经济发展初期整体偏低,此时的产业生态系统适应性与资源环境承载力耦合性协调性较弱; 发展后期,交通通达、人口集聚、产业规模逐步提升,资源环境承载力韧性进一步提升,耦合协调性增强。     

利用生态位适宜度模型评价土地利用环境脆弱性效应

土地利用对环境脆弱性具有重要影响,土地利用与生境条件匹配越好,土地利用的环境脆弱性效应值会越低。该文通过生态位适宜度模型将土地利用对环境脆弱性的影响定量化。选择典型生态环境脆弱区黄河三角洲垦利县的农用地,通过野外调查选择样地,构建各土地利用方式的生态位适宜度模型,在此基础上,对各土地利用生态单元的生态环境现实条件与现状土地利用方式所要求的最佳生态环境进行比较计算生态位适宜度,获得土地利用环境脆弱性效应分布图。研究结果表明,垦利县土地利用的环境脆弱性效应整体良好,棉田是决定整个垦利县环境脆弱性发展的土地利用方式;土地利用强度与土地利用环境脆弱性效应之间呈现为正相关趋势;灌溉条件和土壤盐分是决定土地利用环境脆弱效应值高低的主导环境因子。该研究结果对指导土地的合理利用与管理,防止土地退化和促进生态环境改善具有一定意义。     

有机农业的环境效益评估

常规农业所带来的环境破坏影响越来越被人们所认识。有机农业作为一种新型农业发展模式 ,以保持农业可持续发展和环境影响最小化为其基本原则 ,近 10 a在全球得到迅速发展和推广。与常规农业相比 ,有机农业的环境破坏风险较低。介绍了有机农业的发展现状 ,并就有机农业可能影响到的水环境、土壤环境、大气环境、生物多样性以及人类健康等方面进行探讨 ,以全面评估有机农业的环境效益     

基于环境因子和联合概率方法的土壤有机质空间预测

<正>土壤连续属性(如土壤中养分含量、重金属含量等)的空间分布特征和定量分布信息是进行土壤质量评价和区域环境综合评估的基础。精准农业战略的实施和各种区域生态评价均需要更详细更精确的土壤属性信息作为依据[1-2]。因此,土壤属性空间预测一直是土壤学研究的热点问题。经典地统计学以各种克里格插值法为代表,是土壤属性空间预测中的常用方法。但该方法缺乏对辅助信息(如环境信息)的有效利用[3-4],导致预测精度降低[5]。而土壤景观定量模型的理论依据就是土壤与环境的关系,但该法忽略了采样点之间的空间相