北方农牧交错带种植业能值分析 ——以武川县为例

应用能值理论从农户生产的角度分析了武川县种植业不同作物生产能值。结果表明：该县种植业生产系统能值投入率与产出率“双低”，应增加系统投入以提高产出水平；系统环境负荷率不高，不可更新环境资源破坏严重，应提高可更新环境资源利用效率、加强水土保持工作；辅助能值投入中有机能值略高于无机能值，应按适当比例增加辅助能值投入以提高系统生态经济效益，粮食产出能值中玉米、油菜所占比重高，系统结构调整应遵循生态经济原则，压缩马铃薯面积、提高玉米、油菜等作物播种面积。     

森林生态系统土壤碳库对氮沉降的响应研究进展

大气氮沉降的不断加剧,改变了土壤理化性质,直接影响植物的生长与发育,间接影响了陆地生态系统碳库,进而可能改变全球气候变化进程。森林是陆地生态系统的主体,因此,弄清氮沉降如何影响森林生态系统碳库,对预测全球气候变化具有重要意义。笔者旨在详细分析氮沉降对森林生态系统土壤碳库输入和输出的影响,阐述氮沉降对森林生态系统凋落物分解、细根周转和土壤呼吸的影响研究进展和作用机制。截至目前,关于氮沉降对于陆地生态系统的影响研究报道较多,且国内外诸多学者也在森林生态系统土壤碳库对氮沉降的响应领域开展了较多试验研究,但多集中于碳输入和输出的总量分析,而对输入和输出各个组分的研究相对较少。笔者综述了国内外有关森林生态系统碳库输入和输出各组分对氮沉降响应的相关研究,为进一步揭示其响应机制和途径提供参考依据。     

4M-software package for modelling cropping systems

4M is an easy-to-handle software that has been designed for both educational and scientific purposes. Our main goal in developing 4M was to preserve the features of CERES in a user-friendly software that can be easily extended with additional modules. The package has several characteristics that make it more than a simple crop model. 4M offers optional routines for several processes of the described soil-plant-atmosphere system. The users can build different system models, according to specific purposes. 4M includes input data generators for estimating soil and weather input data that are difficult to measure. 4M is able to simulate crop rotations by using the final conditions of the system after crop harvest as initial conditions for the following crop.     

生态脆弱区耕地集约利用变化的能值分析

为了进一步分析生态脆弱区农地集约利用变化对区域农业经济和生态环境的影响,利用综合研究方法定量表征农业投入、产出、产投比的研究显得十分必要。以处于典型农牧交错区的宁夏盐池县为案例区,利用能值分析的计算方法探讨了研究区实施生态退耕后的2001-2008年耕地劳动力和农资投入、产出、产投比的动态变化特征。结果表明：随着种植面积的变化,单位面积劳动力投入总体呈下降趋势,而农资投入呈波动上升趋势;单位面积产出大幅度波动,而产投比呈波动下降趋势;产投比的波动方向受劳动力投入、农资投入和降水量的制约明显。研究结果显示,生态退耕后,单纯注重增加农资投入、扩大种植面积,而忽视高素质劳动力的投入以及因地制宜利用气候条件,可能是耕地产投比波动下降的原因;同时,研究区农资投入强度的增加,使农业面源污染风险加大。     

3种水旱两熟轮作制养分运筹研究进展

以中国长江流域的3个主要水旱两熟轮作制稻-麦、稻-油和稻-玉为研究对象,分析讨论了3个水旱轮作系统中化学肥料养分投入与养分运筹特性、养分投入种类、投入量以及基肥与追肥的比例等方面问题。发现长江流域水旱轮作系统中水稻季施肥量占整个系统中投入肥料总量的比例在稻-玉轮作系统中较低(47.8%),在稻-油轮作制中基本持平(51.4%),而在稻-麦轮作制中较高(54.7%)。与其他2种轮作制相比较,稻-玉轮作中作物总产量施肥经济效益和肥料利用效率均有明显提高,具有广阔的推广前景。     

洱海流域稻蒜轮作系统小农与规模经营户化肥N投入及成本效益研究

稻-蒜轮作模式下不合理施氮肥所引起的N素流失是造成洱海流域污染的主要原因,而小农普遍化肥N投入过量。鼓励适度规模经营和转变生产方式已成为突破农业可持续发展瓶颈的发力点,越来越受到大家的关注和重视。笔者通过入户调研方式,考察了洱海流域水稻、大蒜种植散户和规模化经营农业组织在稻-蒜水旱轮作模式下生产成本效益与化肥N养分投入情况。结果表明：洱海流域适度规模化的农业经营,不仅大大降低了生产中化肥N养分的投入,从源头上预防农田面源污染,而且转变农业生产方式,积极采用环境友好型种植经营模式,如有机稻栽植、稻-鱼生态耕作模式和改变传统施肥方式,实现了面源污染风险防控,同时获得更高的收益,凸显了规模经营的优势。洱海流域规模化经营农业组织发展相对慢且数量少,需要各级政府全方位给予政策扶持。     

Auswirkungen der Züchtung bei Winterweizen in einem landwirtschaftlichen System mit geringer Betriebsmittelzufuhr von außen

Impact of Wheat Breeding in an Agricultural Low External Input System
Low external input systems, e.g. ecological agriculture, are able to solve problems concerning environmental pollution, diminishing ressources, and overproduction. Since growing conditions of winter wheat are very different in ecological agriculture as compared to conventional systems, the impact of genetic improvement of winter wheat in low external input systems is not well known. Investigations were carried out in two years at two ecologically managed farms using 24 genotypes of winter wheat of different periods of release (about 1900 to 1983). The results can be summarized as follows:
1. The tendency towards higher yields among modern varieties as compared to older cultivars in ecological agriculture was highly significant.
2. The rate of yield improvement was smaller under low external input as compared to conventional conditions results. Yield improvement was greatest in recent decades.
3. In ecological agriculture higher yields among modern varieties resulted from an increased harvest index along with an unchanged biomass production, improved resistance properties, and higher ear weight. Reduced plant height probably has negative effects.
4. Baking quality was improved clearly by wheat breeding.
5. Further genetic improvement of winter wheat yields in low external input systems may result from increased biomass production along with a constant or enhanced harvest index, improved resistance properties, increased plant height, and pronounciation of ear weight.     

不同施肥条件对玉米生长季耕层土壤微生物量碳的影响

为了研究不同施肥条件下棕壤长期定位试验玉米整个生长季微生物量碳含量的动态变化,试验采用氯仿熏蒸、灭菌、提取,TOC测定的方法研究了15个不同施肥处理对耕层土壤微生物量碳含量的影响。结果表明,施用有机肥料可以显著提高土壤微生物量碳含量,随着有机肥用量的增加土壤微生物量碳提高,在玉米的生殖生长阶段其含量达到最大。单施化肥区土壤微生物量碳含量在玉米整个生长季节都处于一种波动变化,在玉米前期,其含量受温度、水分、作物吸收等影响较大;而到了生殖生长阶段,微生物量碳含量有逐渐升高趋势,但上升幅度不大;成熟期微生物量碳含量迅速下降,都低于播种前。     

绿色低碳约束下重庆能源DEA效率实证分析

客观评价重庆能源投入产出效益,探究环境污染、能源消费和经济增长之间的关系,进行能源结构优化,是当前重庆能源消耗走向绿色低碳方向发展面临的重大问题,也是重庆制定节能减排政策、能源发展战略和经济规划的重要基础。本文将能源投入和经济社会等产出因子科学分组,运用数据包络分析技术（DEA）,通过构建的能源需求结构方程以及DEA模型,对重庆能源消费进行了一系列DEA实证研究,得到了重庆能源投入产出规模效率在不同历史时期、不同阶段的变化规律,获取了能源冗余投入（径向改进和松驰改进）值、规模效应值、综合技术效率值和纯技术效率值,确定了DEA弱有效、DEA强有效、DEA完全有效的生产前沿面,并在此基础上对2016-2020年重庆能源结构进行了优化。研究成果可以为确定重庆能源绿色低碳发展方向、优化“十三五”重庆能源消费结构提供科学依据。     

不同氮肥处理下玉米中营养成分的分析

为考察氮肥对玉米品质的影响和探讨玉米合理的氮肥处理,采用田间试验和室内分析相结合的方法,研究不同氮肥处理下玉米中蛋白质、脂肪、氨基酸和维生素的含量。结果表明：在玉米的不同生长阶段都施以不同数量的氮肥（基肥：68 kg/hm²;拔节期：52 kg/hm²;大喇叭口期：30 kg/hm²;开花期：30 kg/hm²;灌浆期：45 kg/hm²）,氮肥施用总量为225 kg/hm²时,玉米中蛋白质和脂肪含量最高,分别可达12.82%和9.68%,分别比对照（处理1）高86%和72%;而且在该处理条件下,所检测的所有氨基酸和维生素B1、B2和B6的含量高于其他处理。与其他施肥方式相比,此处理氮肥施入总量最少,因此合理的施肥方式不仅能改善玉米中营养成分的含量,而且能减少肥料的施加量,节约成本。     

Analysing the energy balances of sugar beet cultivation in commercial farms in Germany

Energy balances are increasingly used to assess the energy efficiency and productivity of agricultural production. In this study, energy balances for sugar beet cultivation in commercial farms in Germany were calculated. 109 farmers with 285 fields were interviewed about the sugar beet cultivation 2004. The energy input and the energy output were calculated with standardised balance-sheet approaches and energy equivalents. Calculated energy balance parameters were the energy gain (energy output less input), the output–input ratio (energy output versus input) and the energy intensity (energy input versus natural yield measured in Grain Equivalents). A factor analysis was performed to explain the variation of the energy balance parameters between the fields by crucial factors for energetic efficiency and productivity. Fields with similarly valued factors were grouped into common clusters by a cluster analysis and a discriminant analysis. The influence of specific growing conditions and cultivation methods on the energy balances were examined for the clusters.Total energy input (median: 17.3 GJ ha⁻¹), energy output (261.7 GJ ha⁻¹), energy gain (244.6 GJ ha⁻¹), output–input ratio (15.4) and energy intensity (87.4 MJ GE⁻¹) revealed a significant variation. The total energy input was significantly lower and the energy yield was significantly higher than in previous studies. Thus, the energy gain and the output–input ratio have clearly risen compared to earlier studies. Today, sugar beet cultivation is energetically more productive and efficient than the cultivation of many other arable crops in Middle Europe.The intensity of the cultivation measures irrigation, catch crop cultivation, tillage and N fertilisation as well as the management of all cultivation measures and the site were determined as crucial factors for energy efficiency and productivity. The intensity of the different cultivation measures influenced the total energy input significantly, but no influence on the energy output was determined. In contrast, the cultivation management (quality and adaptation of cultivation measures) was mainly responsible for the energy output. Whereas the cultivation management mostly explained the energy gain, the factor cultivation management and the factors representing cultivation intensity together were responsible for the output–input ratio.Cluster and discriminant analysis resulted in the formation of 13 clusters. For clusters with an above-average energy gain and output–input ratio, the intensity and in particular the management of cultivation measures were essential for optimising the energy balance.     

Getting the Most Out of Sorghum Low‐Input Field Trials in West Africa Using Spatial Adjustment

Breeding sorghum for low‐input conditions is hindered by soil heterogeneity. Spatial adjustment using mixed models can help account for this variation and increase precision of low‐input field trials. Large small‐scale spatial variation (CV 39.4 %) for plant available phosphorus was mapped in an intensely sampled low‐input field. Spatial adjustments were shown to account for residual yield differences because of this and other growth factors. To investigate the potential of such models to increase the efficiency of low‐ and high‐input field trials, 17 experiments with 70 sorghum genotypes conducted in Mali, West Africa, were analysed for grain yield using different mixed models including models with autoregressive spatial correlation terms. Spatial models (AR1, AR2) improved broad sense heritability estimates for grain yield, averaging gains of 10 and 6 % points relative to randomized complete block (RCB) and lattice models, respectively. The heritability estimate gains were even higher under low phosphorus conditions and in two‐replicate analyses. No specific model was best for all environments. A single spatial model, AR1 × AR1, captured most of the gains for heritability and relative efficiency provided by the best model identified for each environment using Akaike's Information Criterion. Spatial modelling resulted in important changes in genotype ranking for grain yield. Thus, the use of spatial models was shown to have potentially important consequences for aiding effective sorghum selection in West Africa, particularly under low‐input conditions and for trials with fewer replications. Thus, using spatial models can improve the resource allocation of a breeding program. Furthermore, our results show that good experimental design with optimal placement and orientation of blocks is essential for efficient statistical analysis with or without spatial adjustment.     

全球金融危机中的我国金融业及农业风险分析*

摘要：产业结构的变动是国民经济发展的重要特征,投入产出模型是检验经济中各产业的相互联系,进而分析一个国家或地区的宏观经济运行情况的一种经济数量分析方法。面对全球金融危机,本文运用投入产出表对金融产业与其他产业结构进行关联分析是深刻揭示金融产业结构内在机理的重要方法。本文选用了中间投入率、影响力系数、感应力系数三个指标来分析在全球金融危机中,北京、上海金融业的发展问题。研究发现,金融危机对于中国经济产业的直接冲击不会太大,但是对北京、上海的冲击可能是相对严重的。当前需要注意截断房地产开发业金融业的强烈作用,同时维护农业的发展。关键词：金融危机,投入产出;中间投入率,中国;北京;上海     

Characteristic ‘fingerprints’ of crop model responses to weather input data at different spatial resolutions

Crop growth simulation models are increasingly used for regionally assessing the effects of climate change and variability on crop yields. These models require spatially and temporally detailed, location-specific, environmental (weather and soil) and management data as inputs, which are often difficult to obtain consistently for larger regions. Aggregating the resolution of input data for crop model applications may increase the uncertainty of simulations to an extent that is not well understood. The present study aims to systematically analyse the effect of changes in the spatial resolution of weather input data on yields simulated by four crop models (LINTUL-SLIM, DSSAT-CSM, EPIC and WOFOST) which were utilized to test possible interactions between weather input data resolution and specific modelling approaches representing different degrees of complexity. The models were applied to simulate grain yield of spring barley in Finland for 12 years between 1994 and 2005 considering five spatial resolutions of daily weather data: weather station (point) and grid-based interpolated data at resolutions of 10 km × 10 km; 20 km × 20 km; 50 km × 50 km and 100 km × 100 km. Our results show that the differences between models were larger than the effect of the chosen spatial resolution of weather data for the considered years and region. When displaying model results graphically, each model exhibits a characteristic ‘fingerprint’ of simulated yield frequency distributions. These characteristic distributions in response to the inter-annual weather variability were independent of the spatial resolution of weather input data. Using one model (LINTUL-SLIM), we analysed how the aggregation strategy, i.e. aggregating model input versus model output data, influences the simulated yield frequency distribution. Results show that aggregating weather data has a smaller effect on the yield distribution than aggregating simulated yields which causes a deformation of the model fingerprint. We conclude that changes in the spatial resolution of weather input data introduce less uncertainty to the simulations than the use of different crop models but that more evaluation is required for other regions with a higher spatial heterogeneity in weather conditions, and for other input data related to soil and crop management to substantiate our findings. Our results provide further evidence to support other studies stressing the importance of using not just one, but different crop models in climate assessment studies.     

Layered E-R Model Based Input Technology

The traditional E-R's model can abstract the real world strongly, but the relationship among entities in E-R's model is very mixed and disorderly .In order to improve the productivity of the module of data input,the layered E-R model based input technology is presented. The logic model( relational model) produced by the traditional E-R model is layered by primary keys. According to the layered model ,the input interface is produced .First the input interface of 1th-tier entity is produced .By using the input interface of 1th-tier entity ,the input interface of 2rd-tier entity is produced ,until the input interface of the last tier is produced.     

THE SOLUTION OF LOAD TIME FUNCTION IN INPUT EXCITATION OF DYNAMIC-STATE RESPONES OF A TOWER CRANE

According to the proporties of mechanisms in different working orders,this pa-per provides the load-time function by dynamic view. The input excitation is useful for the study of tower crane dynamic-state,and true for selution of tower crane dynamic equation. The view andway in the paper have the meaning of theory and practice for other engineering machinery     

黄淮海地区粮棉作物生产力的研究

黄淮海地区光、热、水资源较丰富,气候-土壤资源的生产潜力较大。本文在对作物各层次生产力计算方法研究的基础上,对该地区冬小麦、夏玉米、夏大豆、棉花等作物各层次生产力进行了计算。初步认为,在一定的农业技术水平条件下,近期(2000年以后)粮棉生产力比1989年可增加1/3,远期(30～50年以后)可增加1倍或稍多。     

稳定性长效复合肥恩泰克对马铃薯产量的影响

为解决习惯施肥费工费时,肥料投入多,利用率不高等问题,选用德国巴斯夫公司最新研制的新型环保肥料在马铃薯上试验,以期减少施肥用量、提高马铃薯产量。通过多点田间同田对比试验,研究了恩泰克稳定性长效复合肥在马铃薯上的增产效果,比较了习惯施肥与恩泰克投入产出经济效益。研究表明：恩泰克比习惯施肥降低了肥料用量,增加马铃薯产量,增产幅度在8％～20％之间,增产的同时,还改善了马铃薯的均匀度。增加了商品率;与习惯施肥相比。恩泰克一次施用即可满足马铃薯整个生育期的需求,减少了施肥的劳动力投入：投入产出分析显示：所有试验点恩泰克施肥的产出都比习惯施肥高,每公顷依次高出1000元、2640元、2417元、1484元和5400元。各试验点马铃薯产出增加值远远大于投入的增加。结果表明施用恩泰克可减少施肥次数、节约人工,减少施肥量、增加产量,经济效益好,应用前景广阔。     

An Analysis of the Loop Performance of the PLL-FM

Analyzing the responses of three kinds of PLL-FM ways and their stabilities. The analyses have shown that the circuits of these PLL-FMs show Low-pass property in the input phase,and have different characteristics to modulation signals in accordance with different ways of PLL-FM.     

The Diagnostic Model of Cotton Aphids Based on Leaf Textural Features

[Objective] The aim of this research is to explore the possibility of rapid identification of aphid damage to cotton leaves by identifying the hyperspectral image about healthy and aphid damage cotton leaves. [Method] Taking Xinluzao 45 as material, hyperspectral images of healthy and damaged cotton leaves by aphids were obtained, and hyperspectral image information was extracted from interested regions of different cotton samples. Then three descending dimension methods were used to extract hyperspectral feature, and Gray-Level Co-occurrence Matrix to extract image texture feature. Finally a cotton aphids damage diagnostic model was built up. [Result] The prediction accuracy based on all textural samples input Random frog-partial least-square-linear discriminant Function (RF-PLS-LDA) model was 91.49%. The prediction accuracy based on energy data input principal component analysis-loading partial least-square-linear discriminant function (PCA-Loading-PLS-LDA) model was 92.55%. [Conclusion] The second-order statistics (energy) of gray co-occurrence matrix can be used to simplify the model, reduce the computation and improve the stability of prediction. Based on the texture feature vector, the identification of aphid cotton leaves can be realized effectively, which provides a method for the rapid identification of insect pests.