关键词： 气候变化   农业生产   因子分析   对策  

摘要： 气候变化会改变地区的温度、光照、水资源等,给农业的种植制度、管理方式、病害防治等多个方面带来不可忽视的影响。详细说明了气候变化对农业生产中各个因子的影响,提出了规避影响的措施,希望给相关的研究者提供一定的帮助。

关键词： 气候变化   Thornthwaite   Memorial模型   周期规律   时空特征   关中-天水经济区  

摘要： 以1960—2014年关中—天水经济区所辖七市一区气象站点逐日气温和降水量实测值为基础,利用Thornthwaite Memorial模型表征气候变化对农业生产造成的影响,综合运用气候倾向率、Morlet小波函数、MannKendall非参数检验法、Yamamoto分析、IDW空间插值对其时空变化特征进行诊断分析.结果表明:关天经济区近55年来,平均气候生产潜力为1 053.8 kg/(hm^2·a),呈逐年增加趋势,并于20世纪90年代发生弱突变.周期变化呈现大小尺度相互嵌套,与研究区降水周期变化基本一致.空间分布区域差异性明显,表现为南部高于中部、东部高于西部.降水是制约经济区农业发展的主导因素,增温和增湿均有利于区域农业生产,但增湿效应更为显著,此外,研究区气候暖湿化的趋势是促进农业发展的重要原因.

关键词： climate change   food security   sustainability  

摘要： Agriculture is now facing the perfect storm' of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic-assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change.

关键词： Adjustment costs   agricultural production   climate change   dynamic duality   Q11   Q54  

摘要： We construct a stochastic dynamic dual model to investigate the structural adjustment of two aggregate output and three aggregate input categories in US agriculture under stochastic climatic change. More than a century of national annual data (1910-2011) is used in the empirical analysis. No constraints on asset fixity are imposed. Results indicate that, with rational expectations, both output categories as well as all input categories exhibit quasi-fixity in response to market change and stochastic climate change. Crops adjust more than twice as fast as livestock-49% versus 20% of the way toward their long-run equilibrium in one year. Fertilizer adjusts most rapidly toward equilibrium levels (88% in one year), and capital adjusts most slowly (5% in one year). Labor oscillates rather than converging smoothly toward equilibrium;its distance from equilibrium is the same as if it adjusted 59% of the way toward its optimal level in one year. Failing to anticipate climate change dramatically slows the estimated rate of adjustment for two netputs and modestly speeds the rate for two others, thus likely increasing overall adjustment costs. Failing to account for uncertainty in anticipated climate change has little impact on adjustment rates.

关键词： Climate change   Yield variability   Vulnerability analysis   Adaptation   Loess Plateau   County level  

摘要： Understanding how the vulnerability of agricultural production to climate change can differ spatially has practical significance to sustainable management of agricultural systems worldwide. Accordingly, this study developed a conceptual framework to assess the agricultural vulnerability of 243 rural counties on the Chinese Loess Plateau. Indicators representing the climate/agriculture interface were selected to describe exposure and sensitivity, while stocks of certain capitals were used to describe adaptive capacity. A vulnerability index for each county was calculated and the spatial distribution was mapped. Results showed that exposure, sensitivity, and adaptive capacity occur independently, with most contributing indicator values concentrated in a narrow range after normalization. Within the 49 most vulnerable counties, which together encompass 81 % of the vulnerability index range, 42 were characterized by high exposure and sensitivity but low adaptive capacity. The most vulnerable area was found to be located in the central northeast-southwest belt of Loess Plateau. Adaptation measures for both ecological restoration and economic development are needed and potential adaptation options need further investigation.

关键词： Conservation agriculture   Tropical   Soil organic carbon   Climate change mitigation   Carbon sequestration   Zero-tillage   Crop residues   Crop diversification   Nitrogen  

摘要： Conservation agriculture (CA), comprising minimum soil disturbance, retention of crop residues and crop diversification, is widely promoted for reducing soil degradation and improving agricultural sustainability. It is also claimed to mitigate climate change through soil carbon sequestration: we conducted a meta-analysis of soil organic carbon (SOC) stock changes under CA practices in two tropical regions, the Indo-Gangetic Plains (IGP) and Sub-Saharan Africa (SSA), to quantify this. In IGP annual increases in SOC stock compared to conventional practice were between 0.16 and 0.49 Mg C ha(-1) yr(-1). In SSA increases were between 0.28 and 0.96 Mg C ha(-1) yr(-1), but with much greater variation and a significant number of cases with no measurable increase. Most reported SOC stock increases under CA are overestimates because of errors introduced by inappropriate soil sampling methodology. SOC increases require careful interpretation to assess whether or not they represent genuine climate change mitigation as opposed to redistribution of organic C within the landscape or soil profile. In smallholder farming in tropical regions social and economic barriers can greatly limit adoption of CA, further decreasing realistic mitigation potential. Comparison with the decreases in greenhouse gas emissions possible through improved management of nitrogen (N) fertilizer in regions such as IGP where N use is already high, suggests that this is a more effective and sustainable means of mitigating climate change. However the mitigation potential, and other benefits, from crop diversification are frequently overlooked when considering CA and warrant greater attention. Increases in SOC concentration (as opposed to stock) in near-surface soil from CA cause improvements in soil physical conditions;these are expected to contribute to increased sustainability and climate change adaptation, though not necessarily leading to consistently increased crop yields. CA should be promoted on the ba

关键词： 非洲农业   气候变化   影响评估   水资源   适应  

摘要： 尽管非洲是世界上温室气体排放总量或人均排放量最少的地区,但在承受气候变化造成的恶劣影响方面首当其冲。气候变化已经给非洲的水资源、农业、生物多样性、人类健康和国家安全等带来诸多严重影响,粮食生产和水资源一直是非洲长期面临的两大难题,也是深受气候变化影响的两大领域。本文系统梳理了气候变化对非洲水资源系统和农业生产影响的研究成果和不足,以期为非洲气候变化影响评估工作提供一定参考和借鉴。已有的观测结果表明,气候变化导致非洲许多山脉冰川面积正在大范围缩减、大部分地区降水量有所减少,降雨的年际间分布也更为不稳定,通过水文模型的模拟预测,未来气候变化将进一步影响降水量和非洲部分地区河流的径流量,导致非洲水资源供给压力加大。同样,气候变化也给非洲农业生产带来了巨大的挑战,无论是观测结果分析,还是统计模型和作物模型等对不同气候情景和时间尺度下非洲农业的模拟研究,都显示气候变化对非洲农业以负面影响为主,导致非洲干旱加剧、生长季改变和粮食产量下降,并可能危及非洲的粮食安全。然而,现有研究结果还存在较多不确定性,其主要集中在未来气候情景数据、研究方法、数据的质量和数量等方面。与世界其它地区相比,非洲气候变化影响研究无论是研究的深度和广度都还较欠缺,需要在未来的研究中进一步加强,以探寻减缓气候变化对非洲水资源和农业不利影响的有效途径。

关键词： 气候变化   喀斯特地区   农业   影响   策略  

摘要： 全球气候变化已成为普遍共识,应对气候变化对农业生产所带来的危害是全世界所应关注的问题。中国南方以贵州为中心的喀斯特地貌区,山高坡陡,地形破碎,其特殊的地质、气候背景和尖锐的人地矛盾使该区生态环境脆弱、敏感、环境容量低、稳定性差。以严重水土流失——石漠化为主要特征的生态严重威胁着区域社会经济可持续发展和2.2亿人口赖以生存的空间。因此,气候变化背景下中国南方喀斯特地区的农业发展备受学术界和政府关注。

关键词： 气候变化   化学品投入效率   农业面源污染  

摘要： 农业面源污染是人类不合理的经济活动与脆弱的生态环境相互作用的结果。通过梳理有关文献,从农业面源污染的现状、成因和防治体系三方面对农业面源污染的研究进展进行评述,在此基础上揭示气候影响农业面源污染的直接和间接路径,气候通过地表径流和地下渗漏方式产生农业面源污染,同时气候变化使农户产生不科学的生产调整行为进而加剧农业面源污染。研究这一关系对于把握气候变化的客观规律,完善基于气候适应性的污染防控体系有重要意义。

关键词： 气候变化   粮食安全   气候智能型农业  

摘要： 全球变暖的速度正在加快,这是人类工业革命以来不可持续的做法对环境破坏产生的恶果。气候智能型农业对全球继续变暖的减缓、适应和粮食不安全的问题,提供了相关的能力建设、方法指导和推广措施建议。气候智能型农业对经济和社会的发展的重大影响使得许多发展中国家也将受益,国际社会承诺对粮食安全、适应和减缓的目标加大投资,从而解决农业问题,特别是推广气候变化减缓和适应技术。