Modelling the spatial allocation of second-generation feedstock (lignocellulosic crops) in Europe

This paper presents a modelling approach for the spatial allocation of second-generation feedstock (lignocellulosic crops) under a reference policy scenario in European Union of 28 Member State (EU-28). The land-use modelling platform (LUMP) was used in order to simulate the land-use changes from 2010 to 2050. Within the LUMP, the land demand for these lignocellulosic energy crops was derived from the Common Agricultural Policy Regionalised Impact analysis model. Suitability maps were generated for two main energy crop groups: herbaceous and woody lignocellulosic crops, using multicriteria analysis techniques. Biophysical factors (climate, soil properties and topographical aspects), natural and artificial constraints and location-specific land categories were defined as relevant components within the platform. A sensitivity analysis determined the most influential factors to be temperature, precipitation, length of growing period and number of frost-free days. The results of the modelling exercise in the LUMP reflect the significant renewable energy contribution from energy crops in EU-28, which was estimated to be between 2.3 EJ/year (in 2020) and 6.3 EJ/year (in 2050), accounting for 2.3% and 9.6% of total energy consumption in the EU-28. The results of the allocation were aggregated at regional level to analyse trends. Regions with considerably high demand were identified in Germany, the United Kingdom and Poland.     

某金矿区农田土壤重金属污染的人体健康风险

环境重金属污染的人体健康效应是当今社会最为关注的重大环境问题。某金矿区矿业活动导致土壤、地下水、农作物中重金属元素存在不同程度的累积或超标。通过土壤、地下水、蔬菜及粮食作物的样品采集,人群暴露问卷调查,获得了暴露人群的膳食结构参数。以农田土壤中7种重金属元素的综合污染分区内的土壤、地下水、蔬菜、小麦玉米等样品中的重金属元素的平均含量为依据,采用USEPA推荐的人体健康风险评价模型,计算了经口食入、皮肤接触等暴露途径对成年人的健康风险概率。研究表明,研究区存在因重金属导致的不可接受的人体健康高非致癌风险和致癌风险。总体而言,土壤重金属污染愈重地区,区内人体健康风险愈高。地下水中的Cr元素、土壤综合污染区内的Hg元素、污染区内的蔬菜及粮食是危害人体健康的重要因素。因此,禁饮Cr含量高的地下水、禁食污染区内的农作物、修复土壤重金属污染、调整农作物种植结构是保护研究区人群健康的重要环境管理工作。     

Are peatlands cool humid islands in a landscape?

This study proposed that due to their high standing water tables that peatlands would be cold humid islands within their landscape, and especially so relative to farmland on mineral soils. To test this hypothesis, we measured air temperature and humidity at 17 locations along a 7.8 km transect across the UK's largest lowland raised bog from February 2018 to January 2019. Air temperature and humidity were measured hourly for 1 year and supported with spot albedo measurements. The study represented a factorial experiment with respect to sites of measurement, the type of land use (peat vs. arable land) and time of sampling over both the seasonal and diurnal cycles. We show that: (a) That although mean annual temperature was not significantly different between arable and peatlands, the arable land showed a decreased amplitude to its seasonal cycle – this is the reverse of the expected pattern. (b) The albedo of the peatland was significantly lower than that of arable land showing that vegetated peatland still absorbed more solar radiation. (c) The specific humidity was lower on the peatland than on the surrounding arable land. The study showed that while shrubby vegetation exists over a peatland then energy budgets are more likely to be dominated by the lower aerodynamic resistance and lower albedo of the vegetated peatland relative to arable land. Thus, shrub-dominated peatlands will not be a cold humid island in their landscape.     

作物生长季节降水量和农业地下水开采量对地下水变化影响研究——以河北晋州地区为例

晋州地区是典型的农业井灌区,通过对该地区农作物生长季节降水量-农业地下水开采量-地下水埋深之间互动变化特征及其机制研究发现,枯水年份,农业地下水开采量的大小与小麦、玉米生长季节的降水量变化密切相关;平水年份,小麦生长季节的降水量变化对农业地下水开采量影响占主导,其次为玉米生长季节的降水量变化;丰水年,农业地下水开采量仅与小麦生长季节的降水量变化之间具有明显相关性,与玉米生长季节的降水量变化相关性明显弱化。不同水文年降水量变化,在影响农业地下水开采量增减的同时,对地下水的入渗补给量呈现与开采量逆向变化,二者叠加影响地下水位动态变化。平水年份或丰水年份,小麦生长季节地下水埋深增大,玉米生长季节降水量一般能满足玉米需水量,地下水埋深减小。因此,充分利用作物生长季节降水量,对减少地下水开采和高产农业的稳定发展有重要意义。     

Coexistence or contradiction? GM crops versus alternative agricultures in Europe

Agricultural biotechnology (agbiotech) has intersected with a wider debate about ‘sustainable agriculture’, especially in Europe. Agbiotech was initially promoted as an alternative which would avoid or remedy past problems of intensive agriculture, but such claims were soon challenged. Agbiotech has extended the dominant agri-industrial paradigm, while critics have counterposed alternatives corresponding to an agrarian-based rural development paradigm. Amid controversy over environmental and health risks in the late 1990s, an extra issue emerged − the prospect that genetically modified (GM) material would become inadvertently mixed with non-GM crops. In response the European Commission developed a policy framework for ‘coexistence’ between GM, conventional and organic crops. This policy has aimed to ensure that farmers can freely choose among different production systems, which would develop side by side, yet specific proposals for coexistence rules favour some choices over others. Such rules have been contested according to different policy agendas, each promoting their model of future agriculture. Moreover, a Europe-wide network of regional authorities has promoted ‘GM-free zones’ as a territorial brand for green, localised, high-quality agri-food production, whose diverse qualities depend upon symbolic, immaterial characteristics. This alternative has been counterposed to the agri-industrial production of global commodities - symbolised by the European Union, especially its product authorisation procedure for the internal market. ‘Coexistence’ policy was intended to mediate policy conflicts over GM crops, yet it has become another arena for contending agricultural systems, which may not so readily co-exist in practice. Wherever an agrarian-based rural development paradigm gains local support, its alternative agricultures are in contradiction rather than coexistence with GM crops.     

2010年春季西南地区干旱遥感监测及其影响评估

利用国产环境减灾星多光谱、热红外数据以及美国中分辨率MODIS数据建立了2010 年春季我国西南地区的干旱及其影响的遥感监测与评估方法。主要包括：1) 旱情遥感监测,利用环境减灾星多光谱数据和热红外数据构建旱情遥感综合指数监测西南地区的旱情;2) 地表可用水资源遥感监测,主要利用2010 年3 月中旬及去年同期的多光谱数据,对位于云南、贵州、广西境内的三个典型水体的水面面积进行了动态监测,以评估地表水面面积及水位的变化;3) 干旱对农作物的影响,主要通过农作物生长过程曲线分析各省(市) 区的作物受旱情的影响过程,并利用耕地面积与遥感监测作物种植成数、分类成数,以及耕地受旱比例计算作物受旱面积,通过田间实验对不同生育期冬小麦受到水分胁迫条件下的减产结果,确定不同旱情等级对应的粮食减产比例,计算各省(市) 的冬小麦减产数量。结果表明旱情最严重区域在广西西北部、贵州西南部和云南的中部与东北部,冬小麦、油菜、甘蔗等作物生长过程受到明显抑制,受旱面积分别达到9.13×10⁵ hm²、5.43×10⁵ hm²与9.00×10⁵ hm²,冬小麦产量损失达到8.3×10⁵ t,约占2009 年四省市冬小麦总产量的13.7%、全国冬小麦总产量的0.8%和全国粮食总产量的0.16%,对我国粮食总产量影响不大,但云南和贵州的冬小麦减产分别达到48%和31%,对区域粮食供应影响较大。     

1998-2018年中国粮食作物化肥利用效率与减施策略研究

This paper studied the fertilizer rate(FR), fertilizer use efficiency(FUE) and fertilizer overuse rate(FOR) of rice, corn and wheat in China from 1998 to 2018 and briefly analysed the reasons why farmers were willing to apply more fertilizers.(1) The FR of grain in China reached 373.7 kg/ha in 2018, an increase of 26.8% compared to that in 1998. In 2018, the FR for corn was the highest, at 411.2 kg/ha, compared to the values of 338.3 kg/ha for rice and 371.7 kg/ha for wheat.(2) In recent years, the FUE of grain in China has obviously improved, with values of 32.9% in 1998, 36.7% in 2008, and 39.3% in 2018. In 2018, the FUE for rice was the highest(41.2%), followed by that for corn(39.9%), and the FUE for wheat was the lowest(36.0%).(3) By 2018, fertilizer was overused in all zones of rice, corn and wheat. In 2018, the average FOR for wheat reached 69.0%, which was 35.9% higher than that for corn and 42.8% higher than that for rice.(4) The lower price of chemical fertilizers was the main reason leading to overapplication.(5) Establishing market mechanisms and adjusting regional planting structures can be effective in reducing the application of chemical fertilizers.     

农作物种类高光谱遥感识别研究

作物种类高光谱识别研究对发展精准农业具有重要意义。通过原始反射光谱、常用指数、不同形式变换光谱及高光谱特征参数对观测的8种农作物的识别能力进行分析,同时采用识别效率最高的数据变换形式构建BP神经网络模型。结果表明:8种农作物的反射光谱曲线存在较大差异,差异最大的波长位置为0.65μm、0.78μm、0.86μm、0.93μm、1.08μm、1.19μm;无论采用原始光谱计算的指数还是常见卫星传感器对应通道计算的指数,识别农作物的能力从大到小均为SRNDVISAVIDVI;高光谱特征参数SDr对作物的识别效果优于其他光谱形式,构建的BP神经网络模型隐含层节点数为13时总体精度最高,达91.8%。     

中国省级间农产品虚拟水流动适宜性评价

尝试从农业生产安全系统、支持系统和水资源安全系统人手,共选取18个指标,构建我国国内农产品虚拟水流动适宜性评价指标体系.运用层次分析法和投影寻踪等方法对我国31个省级行政区农产品虚拟水流动适宜性程度进行定量评价.结果表明:吉林、黑龙江、湖南、上海、北京等地农产品虚拟水流动适宜性程度最高,而宁夏、西藏的适宜性程度最低.对...     

我国土地评价研究的近今进展

近年我国的土地评价研究已从大范围向中、小范围深入,从大农业综合评价转向农、林、牧单项评价甚至单作物评价,旅游用地评价和城市土地经济评价等非农业用地评价也得以展开。评价理论全面深化,计量方法及遥感和地理信息系统等新技术手段得到日益广泛应用。这些表明,我国的土地评价研究已进入一个新阶段。今后,应进一步拓宽研究领域,努力实现方法的规范化,大力加强基础研究,进一步革新研究手段,建立土地评价数据库。