气候变化对河南省冬小麦和夏玉米灌溉需水量的影响

利用河南省17个站点1961—2012年的气象资料,分析了降雨和潜在蒸散对冬小麦和夏玉米灌溉需水量的影响效应。结果表明,河南省冬小麦多年平均灌溉需水量为59.8~334.3 mm,夏玉米多年平均灌溉需水量为14.5~131.2mm,自南向北逐渐增大;各站点冬小麦和夏玉米灌溉需水量普遍呈下降趋势,其主要原因是生育期潜在蒸散减少和降雨量增加。降雨是影响作物灌溉需水量的首要因素,降雨在雨量和时间分布上均对灌溉需水量产生显著影响;而潜在蒸散的影响小于降雨,但不容忽视。在降雨和潜在蒸散共同影响下,冬小麦和夏玉米灌溉需水量在年际间呈现出更大的波动趋势。     

基于CROPWAT模型的玉米需水量及灌溉制度研究

【目的】研究黑龙江西部气候变化对玉米需水量影响及不同降雨年型下喷灌、膜下滴灌的灌溉制度。【方法】基于黑龙江省肇州县1988—2015年气象资料、作物参数和土壤数据,利用Mann-Kendall趋势检验法分析了玉米生育期内各气象因素变化规律,结合CROPWAT模型研究了黑龙江省西部玉米需水量、有效降雨量和灌溉需水量的年际和各生育期间的变化规律并总结归纳了导致这些变化的气象原因,分析了不同降雨年型作物需水量与有效降雨量的耦合度并制订了相应的喷灌和膜下滴灌灌溉制度。【结果】(1)玉米生长期内,月平均最高温度和月平均最低温度显著升高,月平均风速显著降低;(2)玉米生长期内需水量受最高温度影响,以8.72 mm/10 a的速率增长,变化范围为374.7~537.0 mm;(3)特枯水年、枯水年、平水年和丰水年的需水量分别为500.3、470.8、442.8、395.4 mm。(4)不同降雨年型作物需水量与有效降雨量的耦合度总体呈先升增大后减小的变化趋势;(5)喷灌条件下,特枯水年、枯水年和平水年的灌溉净定额分别为187.4、125.4、49.2 mm;(6)膜下滴灌条件下,特枯水年、枯水年和平水年的灌溉净定额分别为163、95.6、35.8 mm。【结论】在气候变化背景下,该地区有效降雨呈减小趋势,玉米需水量呈增大趋势,除丰水年外,有效降雨量难以满足玉米的需水要求,在农业生产中应根据不同降雨年型在抽雄期和灌浆期进行适量灌溉来保证玉米稳产、高产。     

近期气候变化对东江流域水资源的影响研究

利用东江流域主要气象及水文站点1956-2000年气温、降雨及天然径流量时间序列,采用Mann-Kendall秩次相关法检验了流域各季节及年均气温、降雨等气候要素及天然径流量的变化趋势,分析了流域气候变化特征.并利用相关分析法分析了流域气温和降水与径流的相关性,对未来50年该流域径流量的变化趋势进行了预测.结果表明:流域年均气温总体呈显著增加趋势,而年均降雨量和径流总量变化趋势不显著;全流域降雨与径流为正相关,相关系数为0.928,气温与径流为负相关,相关系数为-0.017,说明降雨与径流的关系更为密切,其在流域径流量的变化中起着主要作用.此外,剧烈的人类活动也使得这些相关性更为复杂.     

不同灌溉方式对降雨入渗深度的影响

为了研究不同灌溉方式对降雨入渗深度的影响,基于田间原位观测试验,分析膜下滴灌和传统地面灌溉2种方式对降雨入渗初始含水率的影响,并应用HYDRUS-2D模型模拟2种灌溉方式下不同降雨条件的入渗深度差异.结果表明:与传统地面灌溉方式相比,膜下滴灌改变了降雨入渗初始含水率,且在玉米不同的生育期,其对降雨入渗初始含水率的影响规律不同.通过不同情景的降雨入渗模拟得到,在初始条件完全相同的情况下,2种方式的降雨入渗深度主要受雨量和时间的影响,在降雨量较小时,膜下滴灌的入渗深度大于地面灌;随着降雨量及时间增加,2种灌溉方式下的入渗深度逐渐趋于一致.不论是玉米苗期阶段还是主要生长阶段,降雨入渗的土壤初始含水率均会对降雨入渗深度产生一定的影响:在玉米苗期阶段,膜下滴灌的入渗深度大于地面灌,而在玉米主要生长阶段,地面灌的入渗深度大于膜下滴灌.     

宁夏引黄灌区滴灌玉米穗位叶光响应特征研究

为提高宁夏引黄灌区滴灌水肥一体化下玉米光响应生理参数的计算精度,探讨玉米吐丝期光合响应机制及光合响应特征,以天赐19为试验材料,设置6个施氮水平,采用Li-6400XT型光合仪测定了2017—2018年玉米吐丝期穗位叶的光响应曲线。选用直角双曲线修正模型等4种常用模型对滴灌玉米光响应过程进行拟合分析,评价和筛选出不同氮素水平下玉米吐丝期最优模型,并利用最优模型计算玉米光响应参数。结果表明,4种模型拟合精度存在差异,且直角双曲线、非直角双曲线和指数模型对氮亏缺处理（N0）的光响应曲线拟合度差,直角双曲线修正模型对各处理拟合度最高,可作为最优模型对玉米吐丝期光响应参数进行计算。玉米光合能力随施氮量增加呈先增后减趋势,光补偿点、光饱和点、最大净光合速率、表观量子效率、暗呼吸速率在施氮360kg/hm2（N4）条件下玉米穗位叶的光响应参数均高于其他处理,在450kg/hm2（N5）条件下出现下降趋势,但降幅较小。由此可见,利用光合参数可判断玉米吐丝期的氮素营养状况,调控滴灌玉米最佳施氮量,提高滴灌玉米光合能力,进而提高产量。     

2000—2012年科尔沁沙地植被与气候因子间的响应关系

利用2000—2012年气温、降水量、归一化植被指数（NDVI）数据,对科尔沁沙地气候与植被变化特征及其定性与定量响应关系进行了分析。结果表明,研究区植被长势自东向西逐渐变差有28.56%的面积呈变差趋势,其余呈变好趋势;多年植被长势呈变好趋势,降水呈微弱增加趋势,气温变化趋势不明显。累积2~3个月降水量、当月及平均2~3个月气温对植被影响较大;降水量增多、年内4—11月份气温升高、4—8月份单月年际变化中4月最低气温升高和6—8月份平均、最高气温降低,均促进植被生长;水热同期比单独因子变化对植被影响更大。NDVI在0.03~0.33时受气温影响显著;在0.33~0.43时受降水量影响显著;在0.43~0.62时受水热共同影响显著;在0.53~0.62时气温升高会抑制生长。当降水、气温分别在一定范围内变化,或在一定范围内变化时的水热共同作用下,NDVI响应于一定范围,且部分响应范围间有共同的重叠响应区域。     

日光温室朝向对进光量的影响分析

在高纬度地区冬季凌晨气温比傍晚低 ,在管理上 ,上午揭帘时间较晚 ,使得温室内下午实际日照时间比上午长。温室内下午日照时间较上午日照时间每增加 0 .2 5 h,获得最大进光量的温室朝向应相应偏西增加 1°。以沈阳地区 (41°4 6′N )为例 ,分析表明在计算条件下 ,在南偏西 5°～ 6°时 ,进光量最大 ,与正南向温室进光量相比 ,增加约 0 .3%。     

喷灌红壤丘陵茶园增产的效应

一、前言江西省地处我国亚热带东段,北纬24°29′至30°05′,东经113°34′至118°29′。境内力红壤丘陵山地起伏,全省平均日照时数为1473～2077.5小时。年平均太阳总辐射量每平方厘米在97.0伍(?)14.5千卡范围,年平均气温为16.2～19.7℃,全年平均降雨量为1341～1934mm,年蒸发量1171～1864mm,     

气候变化对黑龙江省生育期内玉米产量的影响

以玉米为研究对象,基于黑龙江省长时间的气象站点观测数据,结合标准化降水蒸散发指数(SPEI),研究黑龙江省玉米生长季内降水、气温、区域干湿变化特征及对玉米产量的影响。结果表明:黑龙江省降水变化趋势不显著,但最高气温、平均气温和最低气温变化趋势显著。湿润化的趋势主要集中在黑龙江省西北部和东南部,干旱化趋势主要集中在黑龙江省自东向西大部分地区。玉米的气象产量主要受SPEI3-8影响,气温是影响黑龙江省生育期内玉米产量的主要因素。研究结果可为区域水资源合理规划和优化农业种植结构提供参考。     

基于水文气象多因子的夏玉米生育期土壤水分预测研究

准确掌握土壤水分动态变化,对制定灌溉计划至关重要。采用五道沟实验站1991-2018年大田土壤水、地下水埋深、降雨量、水面蒸发、风速、日照时数、气温和绝对湿度7个水文气象因子,经相关分析,筛选出4个关键水文气象影响因子,以影响程度最大的为初始变量,逐个添加到4个因子,分别建立了夏玉米各生育期不同土层(0～0.2、0.2～0.4、0.4～0.6、0.6～0.8、0.8～1.0、0～0.5 m)土壤含水率多元线性回归模型。结果表明:不同土层土壤水分与气象因子均表现出一致性的相关性,其中土壤水分与地下水埋深及绝对湿度的相关性最大;开花-成熟期土壤水分与气温和绝对湿度的相关性最大;其他生长阶段与地下水埋深和绝对湿度相关性最大。随着关键影响因子的增多,其预测精度提高,当影响因子为4个时,R~2最大为0.99。不同土层的土壤水分模型均具有较好的预测能力,随着土层深度的增加,平均相对误差均可控制在0.1以内。该研究对及时掌握作物各生长阶段土壤水变化,指导作物科学灌溉具有重要意义。     

Subsurface drip irrigation for corn production: a review of 10 years of research in Kansas

Kansas State University initiated studies in 1989 to develop the methodology for successful application of subsurface drip irrigation (SDI) for corn production on the deep silt loam soils of the Central Great Plains, USA. Irrigation water use for corn can be reduced by 35–55% when using SDI compared with more traditional forms of irrigation in the region. Irrigation frequency has not been a critical issue when SDI is used for corn production on the deep silt loam soils of the region. A dripline spacing of 1.5 m has been found to be most economical for corn grown in 0.76 m spaced rows. Nitrogen fertigation was a very effective management tool with SDI, helping to maximize corn grain yield, while obtaining high efficiencies of nitrogen and water use. The research SDI systems have been utilized since 1989 without replacement or major degradation. SDI systems lasting 10–20 years are cost competitive for corn production with the more traditional forms of irrigation in the Great Plains for certain field sizes.Communicated by P. Thorburn     

基于气候因子的夏玉米减产成因及应对措施

针对聊城市夏玉米出现的果穗较短、秃顶严重及株籽粒重降低等原因导致的玉米产量降低,对夏玉米生育期的降水、日照、温度和相对湿度等气象因子进行了分析。结果表明,玉米减产原因主要是夏玉米播种期的强降水造成土壤湿度饱和导致烂种、开花授粉期的高温致使授粉不良,以及遇连阴雨寡照天气不能授粉所致。结合聊城市气候及玉米生产状况,提出了应对气象灾害的对策措施。      

1960年以来河南省玉米气候生产潜力估算与种植空间优化

农作物生长直接依赖于降水、光照及温度等自然要素,对全球气候变化的影响最为敏感。基于河南省1960—2015年气候观测和太阳辐射量数据,采用逐步订正法估算了159个县级空间单元的玉米气候生产潜力,并进行河南省玉米种植空间的优化。结果表明：在全球气候变化背景下,受气温和降水双因素驱动,河南省玉米气候生产潜力在1960—2015年间呈倒U形的动态变化,玉米生产高气候潜力空间持续向豫西迁移,弱势气候潜力区自2000年来聚集于河南省北部地区。61.11%的河南省玉米生产优势气候潜力区与玉米优势种植区现状重合,但其他各类型潜力区与种植区现状偏差较大。种植规模分为适当增加、逐步减少、保持稳定3种类型,提出河南省玉米种植空间优化方案和对策建议。     

Extending results from agricultural fields with intensively monitored data to surrounding areas for water quality management

A 45% reduction in riverine total nitrogen flux from the 1980-1996 time period is needed to meet water quality goals in the Mississippi Basin and Gulf of Mexico. This paper addresses the goal of reducing nitrogen in the Mississippi River through three objectives. First, the paper outlines an approach to the site-specific quantification of management effects on nitrogen loading from tile drained agriculture using a simulation model and expert review. Second, information about the net returns to farmers is integrated with the nitrogen loading information to assess the incentives to adopt alternative management systems. Third, the results are presented in a decision support framework that compares the rankings of management systems based on observed and simulated values for net returns and nitrogen loading. The specific question addressed is how information about the physical and biological processes at Iowa State University’s Northeast Research Farm near Nashua, Iowa, could be applied over a large area to help farmers select management systems to reduce nitrogen loading in tile drained areas. Previous research has documented the parameterization and calibration of the RZWQM model at Nashua to simulate 35 management system effects on corn and soybean yields and N loading in tileflow from 1990 to 2003. As most management systems were studied for a 6 year period and in some cases weather had substantial impacts, a set of 30 alternative management systems were also simulated using a common 1974-2003 input climate dataset. To integrate an understanding of the economics of N management, we calculated net returns for all management systems using the DevTreks social budgeting tool. We ranked the 35 observed systems in the Facilitator decision support tool using N loading and net returns and found that rankings from simulated results were very similar to those from the observed results from both an onsite and offsite perspective. We analyzed the effects of tillage, crop rotation, cover crops, and N application method, timing, and amount for the 30 long term simulations on net returns and N loading. The primary contribution of this paper is an approach to creating a quality assured database of management effects on nitrogen loading and net returns for tile drained agriculture in the Mississippi Basin. Such a database would systematically extend data from intensively monitored agricultural fields to the larger area those fields represent.     

全膜双垄沟播栽培对自然降水再分配规律研究

在平坦地块中测定了陇东雨养农业区全膜双垄沟播玉米田对自然降水的再分配规律,比较分析了玉米3种栽培方式对自然降水的有效入渗效应。结果表明,全膜双垄沟播玉米田对自然降水的汇集效果可达到72.46%～87.95%,但在降水量少于1mm和2月份的低温、冰冻、降雪等状况下降水汇集效果较差;对自然降水的降水入渗效果可达到61.44...     

气候变化对水稻生长影响的模拟分析

运用大气环流模式(HadCM3)和统计降尺度模型(SDSM)模拟了漳河地区不同排放情景下(A2、B2)的未来气候变化规律,结合ORYZA2000模型分析了不同气候情景模式下水稻生长的差异,从水稻生产的角度探讨了不同水肥耦合调控方式对各种情景的适用性。结果表明,SDSM对温度、降雨、日照都有较好的模拟效果。在A2情景下,水稻产量减少,灌溉定额和氮肥吸收率增加;在B2情景下,水稻产量较高,水分和氮肥利用率较高,水稻生长状态较好;增加CO2质量分数可以提高产量,同时减少了不同水肥管理模式下产量的差异。间歇灌溉和3次追肥的水肥耦合调控方式对各种气候情景的适用性最好。     

变化环境下岩溶区降水气温分布特征研究

探讨变化环境下岩溶区年降水量、年平均气温的分布特征,并结合水文变异诊断系统和非一致性水文频率计算原理,深入探讨年降水量、年平均气温的变化趋势、成因,印证了变化环境对研究要素的影响是存在的;针对研究区域岩溶发育强度,讨论了其对年降水量、年平均气温之间的关联性。研究结果表明:(1)研究区域各站点年降水量呈减少趋势,年平均气温除个别站点呈上升趋势,年降水量与年平均气温呈负相关;(2)研究区域19个站点中年降水量序列发生变异的有9个站点,以弱变异为主;年平均气温序列全部发生变异,以中变异、强变异为主;(3)变异的发生是确定性成分的加入,这种影响可能来自于气候的、也可能是人类活动的;(4)年降水量、年平均气温在不同岩溶发育区域的变化具有一致性。     

Disentangling the effect of environmental factors on yield and nitrogen uptake of irrigated rice in Asia

Rice yield is the result of the interaction between genotype (cultivar characteristics), environment (climate and soil conditions), and management. Few studies have attempted to isolate the contribution of each of these factors. Here the rice growth model ORYZA2000 was used to analyse the variation in yield, nitrogen (N) uptake, and internal N use efficiency (INUE, grain yield per unit total crop N uptake) of rice in different environments. First, ORYZA2000 was calibrated and evaluated using an empirical data set that spanned three varieties, three years, and eight locations in Asia. Next, we used the model to investigate the relative contribution of indigenous soil N and external N supply and of the weather factors temperature and radiation to observed variation in yield.     

Climate change affects farm nitrogen loss – A Swiss case study with a dynamic farm model

The response of arable crops and grasslands to climatic changes and increasing CO₂ concentration has implications for the operation of farms, in particular for the management of resources such as nitrogen. A simple dynamic farm model (Stella^© model ‘CH-Farm’) was used to analyze the shift in the ratio of N lost via leaching, denitrification and volatilization to N exported with products from dairy or arable production (here defined as relative N loss). The model was run for two types of farms typical of Swiss conditions. Growth parameters for two sequentially grown crops (winter wheat and maize) and grass were determined with the process-oriented models Pasture Simulation Model (PaSim) and CropSyst, respectively. CH-Farm was forced with two assumptions about the transient change in temperature and precipitation, and with or without CO₂ effects. Relative N loss for the baseline was around 1.33 for the dairy-type farm and around 1.05 for the arable-type farm and increased progressively over the 100-year simulation period, with the largest shift in response to the dry/hot scenario. Soil N pools decreased with all scenarios, but at different rates. CO₂ fertilization alleviated the effect of climate change due to increased productivity and N fixation in plants. Adjustment of the growth parameters to progressively increasing temperatures reduced the difference between farm types and positively affected relative N losses mainly through increased productivity and reduced fallow periods between crops. The results suggest that the impact of climate change on relative farm-level N loss depends on physiological adjustments to climatic scenarios, whereas the distribution of land between dairy and arable crop production is less important, and that simple cultivar adjustments can help to mitigate negative effects of climate change on farm-level N use.