抗旱应急预留水量需求估测研究

为了提高抗旱应急管理能力,对区域降水量的波动设置一个可容忍的上下波动幅度,降水量波动超过设定的容忍幅度时,需要运用预留水量进行吞吐调节。依据不同调节方式,提出两种抗旱应急预留水量需求估测模型。以辽宁省为例,利用国家气象信息中心提供的辽宁省8个气象观测站近54年(1956-2009年)降水量数据,分别估测不同调节方式下抗旱应急预留水量需求量并进行了比较分析。上述方法为抗旱应急预留水量需求估测提供了新的思路,为合理配置应急预留水量奠定了重要基础,并且具有可操作性。     

Effects of the 1995–1997 drought on nitrate leaching in lowland England

Abstract. The effect of drought between summer 1995 and 1997 on stream and river nitrate concentrations was investigated using sites close to the long-running meteorological station in Oxford, UK. Nitrate concentrations in the River Windrush were relatively low during the drought, but after it had ended reached the highest level since records began in 1973. The low concentrations during the drought probably reflect a reduced contribution from agricultural runoff. High nitrate concentrations were found in a field drain at Wytham Environmental Change Network site during and after the drought, but discharge was greatly reduced. A woodland stream at Wytham had much lower nitrate concentrations than the field drain but these similarly increased during and after the drought. There was evidence that both a concentrating effect of low water volumes and enhanced soil nitrogen mineralization and nitrification rates were causing concentrations to rise. The effects of mineralization and nitrification were more important in woodland than agricultural land. Nitrate load over the course of a year was determined largely by discharge, but steeper gradients for the relationship between cumulative load and cumulative discharge were seen during and after the drought than before, reflecting the higher concentrations.     

长期干旱胁迫下Mdm-miR160- MdARF17- MdHYL1模块调控苹果生长发育的研究

为了研究长期干旱条件下Mdm-miR160-MdARF17-MdHYL1 调控网络在苹果生长发育中的作用，以GL-3和Mdm-miR160e OE、MdARF17 RNAi、MdmARF17 OE、 MdHYL1 OE及MdHYL 1 RNAi转基因苹果为试验材料，进行为期3个月的长期干旱处理，测定苹果株高、根干质量、根冠比以及叶片净光合速率、胞间CO₂浓度、气孔导度、蒸腾速率、叶绿素荧光值和水分利用效率。结果表明，在长期干旱胁迫下， Mdm-miR160e OE转基因苹果植株更矮化，根冠比、根干质量、光合能力及水分利用效率大于GL-3植株，具有更强的耐旱性； MdARF17 RNAi植株比GL-3更矮，且具有更大的根冠比、根干质量、光合能力和水分利用效率，而MdARF17 OE与之相反； MdHYL1 RNAi植株对长期干旱胁迫更敏感，其株高大于野生型且具有更小的根冠比、更低的光合能力和水分利用效率，而 MdHYL1 OE植物对长期干旱条件具有更强的适应性，生长发育表型与RNAi植株相反。综上所述，Mdm-miR160- MdARF17-MdHYL1调控网络在苹果响应长期干旱过程中发挥了重要功能，为苹果抗旱分子育种提供了候选基因。     

干旱对不同地力水平、不同品种小麦生育性状及产量的影响

在相同的水分条件下 ,对不同地力水平、不同品种小麦的生育性状及产量进行比较。研究结果表明 ,小麦品种 9350 31在高肥力条件下表现突出 ,鲁麦 2 1适应性广 ,在中、低肥力地块上表现最佳     

唐代关中旱灾及其影响初探

根据地方灾害史料记载,统计出唐代关中旱灾的发生规律。结果表明:唐代290年的时间内,共发生旱灾112年次,可以按照旱灾发生的频率将唐代划分为五个阶段。关中旱灾的连续性特征非常明显,连续三年以上的干旱链现象突出。旱灾在月份和季节中的分布极不均匀,季节性连续干旱偏多。唐代关中旱灾灾情较为严重。频繁的旱灾给唐代关中地区的社会生活和自然环境带来了极大的影响。     

生物炭对干旱胁迫下咖啡苗生长及非结构性碳水化合物的影响

为明确在干旱胁迫下施用生物炭对咖啡苗生长及非结构性碳水化合物（NSC）含量的影响，以正常水分处理（W1：土壤水分为最大持水量的65%~70%，不施用生物炭；W2：土壤水分为最大持水量的65%~70%，施用相当于烘干土质量5%的生物炭）为对照，设置不同生物炭处理（D1：不施生物炭；D2：施用量为干土质量的5%）下进行持续干旱与复水的盆栽试验，干旱与复水共设4个处理，分别为持续干旱9 d（DL）、持续干旱13 d（DS）、持续干旱9 d+复水后3 d（DL+R）、持续干旱13 d+复水后3 d（DS+R），分析各器官（根、茎、叶）干物质量、NSC组分含量及其质量的变化。结果表明：与正常水分处理（W1）相比，持续干旱9 d时（DL），D1处理咖啡苗叶的可溶性糖含量、淀粉含量和NSC比率分别下降22.5%、21.1%和21.1%，根的可溶性糖含量和NSC比率分别显著提高8.7%和62.8%，茎的可溶性糖含量和NSC比率分别显著提高22.0%和28.2%。持续干旱13 d时（DS），D1处理较W1处理的根、茎、叶干质量和总干物质量分别下降30.6%、22.2%、34.8%和30.8%，叶的NSC含量和NSC比率分别下降23.7%和16.4%，根的NSC含量和NSC比率分别增加33.8%和57.9%；生物炭处理（D2）较不施生物炭的处理（D1）总干质量增加16.7%，根的NSC含量和茎的NSC比率分别下降18.0%和24.1%，叶的NSC含量和NSC比率分别增加22.8%和15.0%。持续干旱9 d复水后3 d时（DL+R），生物炭处理（D2）对各器官NSC含量恢复作用显著，且与正常水分处理（W1）间无显著差异；干旱13 d复水后3 d时（DS+R），不施生物炭处理（D1）的咖啡苗生长未恢复，而生物炭处理（D2）对咖啡苗恢复作用显著，D2较D1处理的总干质量增加20.3%，叶的NSC含量增加22.7%，根和茎的NSC含量分别下降11.8%和15.3%。可见，施用生物炭是增强咖啡抗旱性和减缓咖啡NSC组分剧烈变化的有效途径。     

Performance of Agricultural Systems under Contrasting Growing Season Conditions in South-western Quebec

Climate change will alter temperature and rainfall patterns over North American agricultural regions and there will be a need to adapt crop production systems to the altered conditions. A set of field experiments were conducted in south-western Quebec, Canada, with soybean ( Glycine max L.), corn ( Zea mays L.), sorghum ( Sorghum bicolor L.) × sudangrass ( Sorghum sudanense Piper) hybrid and switchgrass ( Panicum virgatum L.) under two tillage and three nitrogen fertility regimes, to study their performance in three successive growing seasons (2001–2003), two of them with unusually warm and dry conditions. The annual crops were established in two tillage systems: conventional and no-till (NT). All crops except soybean were fertilized with three levels of nitrogen: corn – 0, 90 and 180 kg N ha⁻¹, sorghum-sudangrass – 0, 75 and 150 kg N ha⁻¹, switchgrass – 0, 30 and 60 kg N ha⁻¹. The 2001 and 2002 seasons were hotter and drier than the 2003 season, which was the most favourable for crop growth. The capacity of the crops to yield in dry seasons was as follow: switchgrass > sorghum-sudangrass > corn > soybean. The corn and sorghum-sudangrass responses to nitrogen fertilizer were low in 2001 due to the combined effect of dry growing season and coarse soil texture. Soybean did not perform well under NT. Corn yielded better at the highest nitrogen fertilizer rate under NT when the early season was warmer than the normal. Our results show that switchgrass and sorghum-sudangrass could be an option in south-western Quebec if the frequency of hot and dry seasons increase in the future, because of climate change.     

特旱年旱地玉米限额补灌水肥效应分析

采用田间试验方法研究了旱地玉米限额补灌的水肥效应。结果表明，玉米小喇叭口期灌水675mm／hm2，平均增产玉米2171.5kg／hm2，增产率89．27％，灌水生产效率为3.217kg／mm;3种肥料的增产效果为N＞M＞P。未灌水条件下，3种肥料的增产效果为M＞P＞N。配合施用的增产效果为NPM＞NP。     

Drought Tolerance in Cotton: Involvement of Non-enzymatic ROS-Scavenging Compounds

Compounds with reactive oxygen species (ROS)-scavenging ability were studied. High-performance liquid chromatography (HPLC) pattern of polyphenols, contents of proline and carotenoids, and antiradical (AR) capacity were determined. The malonyldialdehyde (MDA) level was also assessed. Tolerant and sensitive cotton genotypes were compared, grown in the Aegean region of Turkey at normal (field capacity) and limited (1/3 field capacity) water supply. Chlorogenic acid isomers and flavonoids were identified in HPLC pattern of polyphenols. At normal water supply, the tolerant genotype was distinguished by a higher content of all polyphenol types, higher proline, carotenoids and AR capacity and lower MDA level compared with the sensitive genotype. In plants subjected to water deficit, a decline of all polyphenol compounds, carotenoids and AR capacity was observed. However, this response was less pronounced in the tolerant than in the sensitive genotype, i.e. despite the stress conditions imposed, the tolerant plants maintained a more effective defence system. The data are corroborated by the weaker structural membrane damage in the drought-exposed tolerant vs. sensitive genotype, according to the MDA test. Hence, diverse chemical types are involved in the non-enzymatic ROS-scavenging system of cotton plants and can be related to the drought tolerance of this important crop.     

应用灰色系统理论评价草地质量初探

以草地优良牧草产量、可食牧草产量、载畜量、牧草利用率和覆盖度为主要指标，应用灰色系统理论中关联工分析的方法，对武威地区３２个类型草地质量进行了评价。结果表明，质量最好的草地是山地草甸，质量最关的是干荒漠和荒漠摹。根据分析结果，提出了武威地区草地质量分级的方案。