松花江流域土地利用格局时空变化分析

为了在流域尺度上揭示21世纪最初10年松花江流域的土地利用变化的方向和强度,笔者基于2000年、2005年和2010年3期Landsat ETM卫星遥感数据,对松花江流域土地利用信息进行提取,并通过对比各子流域在不同时间序列上的差异揭示流域土地利用空间格局和时空变化。结果表明：2000—2010年,流域内湿地面积严重萎缩,其中嫩江水系湿地减少的最为明显。建设用地的面积显著增加,且3个子流域的建设用地面积均呈增加的趋势,其中第二松花江增长的速度最快,2010年比2000年增加了11.52%。整个流域的耕地面积稍有增加,但空间差异明显,表现为嫩江子流域耕地面积显著增加,而松花江干流和第二松花江流域耕地面积减少。在流域尺度上,土地利用转化过程中湿地-耕地、耕地-建设用地的转换较为剧烈,林地具有相对较高的保留率。空间上,土地利用转化强度较大的主要是嫩江中下游平原区和松花江干流下游入河口的平原地区,嫩江子流域各地类间的交叉转换频繁,且各1级地类内部的转化也较多,而松花江干流的转化主要在个别地类。     

亚洲型舞毒蛾中国地理种群飞行能力初探

为了探究亚洲型舞毒蛾的飞行能力,以采自河北和内蒙两地的亚洲型舞毒蛾为试验对象,应用昆虫飞行信息系统,分析亚洲型舞毒蛾的最大飞行速度、累计飞行距离和累计飞行时间。结果表明：亚洲型舞毒蛾雌雄个体间飞行能力有显著差异,雄虫比雌虫具有更强的飞行能力,雄虫平均累计飞行距离为6.76 km,雌虫平均累计飞行距离为1.85 km;1日龄成虫已具备较强的飞行能力,在飞行时间、飞行距离上,雌虫随着日龄的增长呈现出明显的线性下降趋势;交配对雄虫的飞行能力无显著影响,雌虫产卵后飞行能力明显下降。     

不同品种磷肥运筹对砂姜黑土玉米生长及产量的影响

为了进一步提高砂姜黑土生产能力、缓解土壤酸化和防止磷流失导致面源污染,通过田间试验研究了钙镁磷肥用量和不同品种磷肥对砂姜黑土玉米生长和产量的影响。结果表明：在P2O5 用量为90 kg/hm2时,钙镁磷肥、过磷酸钙、磷酸二铵、钙镁磷肥配施磷酸二铵分别比不施磷肥处理玉米增产20.8%、4.8%、5.7%、18.1%。施用钙镁磷肥玉米增产效果最大,并与砂姜黑土传统习惯施用的磷肥品种过磷酸钙、磷酸二铵等处理玉米产量达显著差异。供试土壤钙镁磷肥肥料效应方程为y=22.073x-0.1027x2+5537.4,由此方程可获得最高玉米产量钙镁磷肥(P2O5)用量为107.5 kg/hm2,因钙镁磷肥碱性,用量过高会影响土壤其他养分有效性而降低玉米产量。由此得出,钙镁磷肥是砂姜黑土玉米进一步增产新的施肥技术,其增产机理和施用方法值得进一步研究。     

玉米种质资源的背景与利用

此文综述了国内外玉米种质资源的遗传背景与利用途径方面的研究进展,包括玉米的杂种优势群及杂优模式,及其在育种中的灵活应用,以及各种类型原始材料的利用方法。表明种质资源是玉米育种的前提和基础,深入认识和合理选择种质资源,可以显著提高育种效率,加快育种进程。同时认为,在玉米育种原始材料的选择和构建中,不能仅仅局限于杂种优势群和杂种优势模式,还要根据不同类型的种质资源,以及个人的育种目标和思路加以合理利用。     

塔里木河中游胡杨群落结构特征分析

为了了解生长状况良好的胡杨群落,在塔里木河中游沿岸选择具有代表性胡杨群落,设立1 hm2固定样地,调查分析胡杨林群落结构特征。结果表明：胡杨群落垂直层次优势种较为明显,形成以胡杨+柽柳+芦苇、假苇拂子茅为优势种的荒漠河岸林群落类型;胡杨种群属于稳定型种群,个体数量在不同径级之间分布合理;在不同尺度下,胡杨种群均处于集群分布;胡杨种群在不同发育阶段分布格局由聚集分布向随机分布转变。     

2004：国际水稻年

20 0 4年 ,已被联合国正式命名为“国际水稻年” ,这将是水稻史上又一重要历史事件。国际水稻年的倡议产生于1999年 ,当时 ,国际水稻研究所 (IRRI)的科学家对水稻发展中存在的严重问题日益感到担忧 ,于是请求与联合国粮农组织合作 ,共同发起国际水稻年。粮农组织第三十一次大会通过的 2 / 2 0 0 1号决议就是这一努力的结果。此后由 4 3个国家共同向第 5 7届联大提交了这一提案请求 ,联大最终在2 0 0 2年 12月 16日宣布 2 0 0 4年为国际水稻年。在联大历史上 ,把单个作物———水稻命题为国际年 ,是前所未有的。联大一致认为 ,水稻作为食物…     

不同抚育强度对华北落叶松生长量的影响

为了探求不同密度株数对华北落叶松的影响,通过抚育管理提高华北落叶松年生长量,采用标准地平均生长量对比的方法研究了不同抚育强度对24年生华北落叶松胸径、树高和材积年生长量的影响。结果表明,不同抚育强度对华北落叶松胸径与材积的年生长量有显著影响,随着抚育强度的增大,胸径、材积年生长量逐渐增加,当抚育强度为450株/hm2时,胸径和材积年生长量达到最大值;而抚育强度对其树高无显著影响。     

不同立地条件下“核桃黑”的发生情况调查

为了了解影响核桃产量和质量的“核桃黑”发生情况以及造成“核桃黑”的主要原因。笔者在商洛市山阳县核桃园中根据不同海拔高度确定3种试验地,在每种试验地里随机选择10棵10~15年的核桃树,调查温湿度、虫果率、引起“核桃黑”的病虫害。结果表明,“核桃黑”的发生情况与立地条件有直接关系,“核桃黑”发生率最大的是深山区,浅山区次之,平原区发生的最小;深山区造成“核桃黑”的主要是黑斑病,然后是核桃举肢蛾,而浅山区和平原区的“核桃黑”主要是核桃举肢蛾造成,其次才是黑斑病。调查结果表明：对于“核桃黑”的防治应该在7月13日后开始进行,防治的重点主要集中在防治核桃黑斑病和核桃举肢蛾上。     

氮肥减量后移对玉米冠层生理性状和产量的影响

为了进一步研究氮肥减量后移对玉米生理性状和产量的影响,以‘郑单958’为试材设置5个处理：不施氮(N0)、习惯施氮(N300/2)、减量施氮(N240/2)、减量后移施氮(N240/3)、减量后移施氮(N200/3),完全随机区组设计,3次重复,种植密度75000株/hm2。结果表明,氮肥减量处理(N240/2)与习惯施氮处理(N300/2)相比叶片SPAD值、PN及产量均有所降低,Dualex值则有所增加,但差异并不显著,减量施氮在生产上应切实可行的;减量后移施氮处理(N240/3)与习惯施氮处理(N300/2)和减量施氮处理(N240/2)在出苗后30天和45天的叶片SPAD值、光合速率及产量也均有所降低,Dualex值则有所增加,表现差异也并不显著,但与减量后移施氮(N200/3)差异显著。减量后移施氮(N240/3)与习惯施氮处理(N300/2)、减量施氮处理(N240/2)和减量后移施氮(N200/3)在出苗后60天和75天的叶片SPAD值、光合速率及产量均有所增加,Dualex值则有所降低,表现差异显著。氮肥减量后移(N240/3)处理的玉米植株氮素不但能满足于玉米生长的营养需求、降低投入、提高氮素利用率且产量也得到提高。     

福建武平典型烤烟产区烟叶品质特征分析

为阐明福建武平烟区烤烟的内在质量特征、改善和稳定其烟叶质量风格特色和提高烟叶的工业可用性,以福建武平典型烤烟产区‘云烟87’主栽品种C3F初烤烟叶为试验材料,分析研究该烟区烟叶理化特征及感官评吸质量。结果表明：武平烟叶开片度和叶片厚度存在极显著差异,有8个乡镇中部烟叶的开片度已接近或达到40%的优质烟叶标准;武平县各乡镇中部烟叶总氮、钾和氯含量及钾氯比、氮碱比存在极显著差异;极高的钾含量、偏低的氯含量和适宜的烟碱含量是武平烟区烟叶最显著的特征。不同质地和pH土壤种植的烟叶香气质、杂气和余味3个感官评吸质量指标存在显著差异。     

气候变化对中国东北地区生态与环境的影响

【研究目的】综述了气候变化对东北地区的影响,以期在区域发展中能利用气候变化的有利方面,降低其不利的影响;【方法】根据近年来发表的相关论文,文章综述了东北地区已经发生的气候变化影响及未来可能受到的影响;【结果】结果表明,过去100年东北地区的温度升高明显且降水普遍减少,干旱化趋势严峻。温度的升高改善了东北的热量资源,部分农业生产从中受益。但由于气候变化,目前特殊的生态系统如湿地,冻土退化或消失。未来的气候变化,会改变农业生产布局,降低主要作物的产量,生态系统结构发生改变,农牧带沙漠化的风险增加;【结论】东北地区必须客观认识气候变化的利弊影响,采取相应的适应和应对措施,促进区域发展。     

Impacts and adaptation of European crop production systems to climate change

The studies on anthropogenic climate change performed in the last decade over Europe show consistent projections of increases in temperature and different patterns of precipitation with widespread increases in northern Europe and decreases over parts of southern and eastern Europe. In many countries and in recent years there is a tendency towards cereal grain yield stagnation and increased yield variability. Some of these trends may have been influenced by the recent climatic changes over Europe.A set of qualitative and quantitative questionnaires on perceived risks and foreseen impacts of climate and climate change on agriculture in Europe was distributed to agro-climatic and agronomy experts in 26 countries. Europe was divided into 13 Environmental Zones (EZ). In total, we had 50 individual responses for specific EZ. The questionnaires provided both country and EZ specific information on the: (1) main vulnerabilities of crops and cropping systems under present climate; (2) estimates of climate change impacts on the production of nine selected crops; (3) possible adaptation options as well as (4) adaptation observed so far. In addition we focused on the overall awareness and presence of warning and decision support systems with relevance for adaptation to climate change.The results show that farmers across Europe are currently adapting to climate change, in particular in terms of changing timing of cultivation and selecting other crop species and cultivars. The responses in the questionnaires show a surprisingly high proportion of negative expectations concerning the impacts of climate change on crops and crop production throughout Europe, even in the cool temperate northern European countries.The expected impacts, both positive and negative, are just as large in northern Europe as in the Mediterranean countries, and this is largely linked with the possibilities for effective adaptation to maintain current yields. The most negative effects were found for the continental climate in the Pannonian zone, which includes Hungary, Serbia, Bulgaria and Romania. This region will suffer from increased incidents of heat waves and droughts without possibilities for effectively shifting crop cultivation to other parts of the years. A wide range of adaptation options exists in most European regions to mitigate many of the negative impacts of climate change on crop production in Europe. However, considering all effects of climate change and possibilties for adaptation, impacts are still mostly negative in wide regions across Europe.     

气候变化对中国油料作物的影响研究进展

油料作物是中国重要的粮食作物,对气候变化十分敏感。目前中国食用油自给率较低,存在严重的供需矛盾,油料安全是中国粮食安全中最为薄弱的环节。近年来气候变化也对中国油料作物生产带来了显著影响,因此如何客观准确地评价气候变化对中国油料作物生产的影响,对提高中国食用油自给率、保障粮油安全具有重大意义。综述了气候变化对中国三大主要油料作物（花生、大豆、油菜）影响的相关研究,概括了主要的研究方法和气候变化对油料作物的生长发育及产量、品质以及种植制度的影响,并据此讨论了研究中存在的不足和未来展望。     

覆盖作物及其作用的研究进展

在农作物种植系统中,田间杂草、土壤因素对作物的生长发育、产量和品质的影响一直都是农业领域关注的热点。大量使用化肥和除草剂可以达到作物增产、除草的目的,但其对土壤和环境造成的负面影响,严重制约了农业生产的可持续发展。种植覆盖作物是一种实现农业可持续发展的新策略,可以达到控制杂草、减少氮肥施用、改善土壤质量等目的。本文主要从覆盖作物的起源与发展过程、主要种类和作用及其种植制度等方面,总结了目前覆盖作物的研究进展及其在作物种植中的应用,以期为覆盖作物在我国农业生产中的研究与应用提供理论基础。     

Consequences of climate change for European agricultural productivity, land use and policy

This paper reviews the knowledge on effects of climate change on agricultural productivity in Europe and the consequences for policy and research. Warming is expected to lead to a northward expansion of suitable cropping areas and a reduction of the growing period of determinate crops (e.g. cereals), but an increase for indeterminate crops (e.g. root crops). Increasing atmospheric CO₂ concentrations will directly enhance plant productivity and also increase resource use efficiencies.

In northern areas climate change may produce positive effects on agriculture through introduction of new crop species and varieties, higher crop production and expansion of suitable areas for crop cultivation. Disadvantages may be an increase in the need for plant protection, the risk of nutrient leaching and the turnover of soil organic matter. In southern areas the disadvantages will predominate. The possible increase in water shortage and extreme weather events may cause lower harvestable yields, higher yield variability and a reduction in suitable areas for traditional crops. These effects may reinforce the current trends of intensification of agriculture in northern and western Europe and extensification in the Mediterranean and southeastern parts of Europe.

Policy will have to support the adaptation of European agriculture to climate change by encouraging the flexibility of land use, crop production, farming systems etc. In doing so, it is necessary to consider the multifunctional role of agriculture, and to strike a variable balance between economic, environmental and social functions in different European regions. Policy will also need to be concerned with agricultural strategies to mitigate climate change through a reduction in emissions of methane and nitrous oxide, an increase in carbon sequestration in agricultural soils and the growing of energy crops to substitute fossil energy use. The policies to support adaptation and mitigation to climate change will need to be linked closely to the development of agri-environmental schemes in the European Union Common Agricultural Policy.

Research will have further to deal with the effect on secondary factors of agricultural production, on the quality of crop and animal production, of changes in frequency of isolated and extreme weather events on agricultural production, and the interaction with the surrounding natural ecosystems. There is also a need to study combined effects of adaptation and mitigation strategies, and include assessments of the consequences on current efforts in agricultural policy to develop a sustainable agriculture that also preserves environmental and social values in the rural society.     

Prospects for ecological intensification of Australian agriculture

World population growth, changing diets and limited opportunities to expand agricultural lands will drive agricultural intensification in the decades ahead. Concerns about the reliance of past agricultural intensification on non-renewable resources, about its negative impacts on natural resources both on and off farm and on greenhouse gas emissions, provide an imperative for future agricultural intensification to become ecologically efficient. We define ecological intensification of agriculture (EIA) as: producing more food per unit resource use while minimising the impact of food production on the environment. Achieving it will require increased precision in the use of inputs and reduction in inefficiencies and losses. It will also require a more holistic view of farming, going beyond efficiencies of single inputs into a single field in a single season to consideration of efficiencies of whole systems over decades. This paper explores the ecological intensification issues facing agricultural production in Australia where opportunities for agricultural intensification are centred on more efficient use of limited and unreliable water resources in both dryland and irrigated agriculture. Ecological efficiencies can be achieved by better matching the supply of nutrients to crops’ requirements both temporally and spatially. This has the added benefit of minimising the opportunities for excessive nutrients to impact on soil health (acidity and dryland salinity) and water quality (pollution of groundwater and eutrophication of lakes and rivers). Opportunities for ecologically efficient intensification are also identified through better integration of crop and livestock enterprises on mixed crop–livestock farms. We define nine desirable attributes of an EIA system: (1) increased agricultural production; (2) efficient use of limited resources; (3) minimal impact on global warming; (4) minimal negative on-site impacts; (5) minimal negative off-site impacts; (6) minimal risk and maximum resilience; (7) preservation of biodiversity in agriculture; (8) preservation of biodiversity in nature and; (9) positive social outcomes. We focus on four technologies and production systems emerging in Australian agriculture: climate risk management; precision agriculture; crop–livestock integration and deficit irrigation. For each of these systems we identify how well they are likely to match the nine desirable attributes of an EIA system. While it seems unlikely that any single technology can satisfy all nine desirable attributes, there is hope that in combination emerging and future technologies will progress Australian agriculture towards greater productivity and ecological efficiency.     

气候变化对中国粮食生产的影响

气候变化对中国粮食生产的影响已得到高度关注,并形成了诸多研究成果,但影响的评估结果存在一定的争议.笔者对21世纪以来百篇国内外相关高质量文献进行整合梳理,总结讨论了气候变化对中国粮食生产的影响.研究表明:(1)1961年以来气候变化主要通过影响作物生长发育、引起种植结构改变、导致农业病虫害和气象灾害加剧的方式影响了中国...     

气候变化对湖南主要农作物种植结构的影响

基于湖南省97个地面气象观测站1961－2008年逐日平均气温、最高气温、最低气温、降水量、日照时数等气象观测资料,选择最佳小网格推算模型推算出500m×500m的高空间分辨率的网格序列资料;基于双季稻、油菜、棉花、柑桔、油茶、烟草等主要农作物生长条件及相关区划研究成果,确立相应农作物种植适宜性气候区划指标;结合地理信息资料,运用GIS技术,开展主要农作物种植适宜性动态气候区划。结果表明：气候变化对湖南主要农作物种植结构均有一定的影响,对双季稻的影响主要表现为熟性搭配区的变化,对油菜、油茶、柑桔的影响主要是最适宜种植面积增大,对棉花、烟草的影响主要最适宜种植面积减少。针对气候变化对湖南主要农作物种植适宜性的影响及相应农作物种植适宜性的气候区划结果,提出应对建议为：充分利用滨湖平原、河谷平原和盆地气候资源,扩大复种指数,提高单位面积产量;充分利用山地气候资源,做大做强湖南油茶产业;充分利用区域气候资源,打造湖南柑桔品牌;充分利用小气候资源,发展湘西、湘南特色烟叶。     

气候变化影响下长江流域油菜产量模拟初步研究

为油菜主产区油料作物种植结构调整、合理布局以及制定适应气候变化的管理措施提供理论依据。以中国三大油料作物之一的油菜为代表,针对油菜主产区之一的长江流域的油菜生产,利用引进的澳大利亚APSIM-Canola油菜模型,结合英国Hadley中心的区域气候模式PRECIS,对SRES A2、B2 2种排放情景下油菜生产状况进行模拟。同时结合多元回归统计方法,分析长江流域气候变化对油菜生产已经造成和未来可能造成的影响,并提出可能的适应性对策。研究表明：（1）油菜雨养产量与关键生育时期（现蕾-抽苔期、抽苔-开花期）内辐射和温度呈显著的负相关,与降水呈正相关。（2）A2、B2气候变化情景下油菜单产均随时间呈降低趋势,21世纪80年代减产幅度最为明显,A2情景下近期（21世纪20年代）、中期（21世纪50年代）、远期（21世纪80年代）油菜产量波动呈加强趋势,且同一时期内A2情景下产量波动趋势均大于B2情景。（3）适当采用调整播种期和栽培方式、改良作物品种等适应性对策可有效降低油菜的减产趋势。     

气候变化对三大粮食作物产量影响研究进展

气候变化对中国农业生态环境及作物产量的影响越来越受到关注。通过总结近十年来国内外的研究成果,着重叙述了气候变化对三大粮食作物的产量影响研究方法及其最新进展,归纳了不同研究方法存在的差异。同时对中国未来粮食产量变化进行了分析,指出存在的问题和可能发展的方向,提出了农业适应气候变化和可持续发展的依据。