An Air Mass Based Approach to the Establishment of Spring Season Synoptic Characteristics in the Northeast United States

The Northeast United States spring is indicative of major meteorological and biological change though the seasonal boundaries are difficult to define and may even be changing with global climate warming. This research aims to obtain a synoptic meteorological definition of the spring season through an assessment of air mass frequency over the past 60 years. The validity of recent speculations that the onset and termination of spring have changed in recent decades with global change is also examined. The Spatial Synoptic Classification is utilized to define daily air masses over the region. Annual and seasonal baseline frequencies are identified and their differences are acquired to characterize the season. Seasonal frequency departures of the early and late segments of the period of record are calculated and examined for practical and statistical significance. The daily boundaries of early and late spring are also isolated and assessed across the period of record to identify important changes in the season’s initiation and termination through time. Results indicate that the Northeast spring season is dominated by dry air masses, mainly the Dry Moderate and Dry Polar types. Prior to 1975, more polar air masses are detected while after 1975 more moderate and tropical types are identified. Late spring is characterized by increased variability in all moist air mass frequencies. These findings indicate that, from a synoptic perspective, the season is dry through time but modern springs are also warmer than those of past decades and the initiation of the season is likely arriving earlier. The end of the season represents more variable day-to-day air mass conditions in modern times than detected in past decades.

A preliminary study of the effects of plastic film-mulched raised beds on soil temperature and crop performance of early-sown short-season spring maize(Zea mays L.) in the North China Plain

To identify a strategy for earlier sowing and harvesting of spring maize(Zea mays L.) in an alternative maize–maize double cropping system, a 2-year field experiment was performed at Quzhou experimental station of China Agricultural University in 2014 and 2015. A short-season cultivar, Demeiya number 1(KX7349), was used in the experiment. Soil temperature to 5 cm depth in the early crop growth stage, crop growth, crop yield, and water use of different treatments(plastic film-mulched raised bed(RF) and flat field without plastic film mulching(CK) in 2014; RF, plastic film-mulched flat field(FF), and CK in 2015)were measured or calculated and compared. Soil temperature in the film-mulched treatments was consistently higher than that in CK(1.6–3.5 °C in average) during the early growth stage. Crops in plastic film-mulched treatments used 214 fewer growing-degree days(GDDs) in 2014 and 262 fewer GDDs in 2015. In 2014, the RF treatment yielded 32.7%higher biomass than CK, although its 9.4% higher grain yield was not statistically significant. Also, RF used 17.9% less water and showed 33.1% higher water use efficiency(WUE) than CK. In 2015, RF and FF showed 56.2% and 49.5% higher yield, 15.0% and 4.5%lower water use(ET), and 63.4% and 75.7% higher WUE, respectively, than CK. RF markedly increased soil temperature in the early crop season, accelerated crop growth, reduced ET,and greatly increased crop yield and WUE. Compared with FF, RF had no obvious effect on crop growth rate, although soil temperature during the period between sowing and stem elongation was slightly increased. However, RF resulted in lower ET and higher WUE than FF. Effects of RF on soil water dynamics as well as its cost-effectiveness remain topics for further study.

Phytoplankton growth and microzooplankton grazing in the central and northern South China Sea in the spring intermonsoon season of 2017

Phytoplankton growth rates and mortality rates were experimentally examined at 21 stations during the 2017 spring intermonsoon(April to early May)in the northern and central South China Sea(SCS)using the dilution technique,with emphasis on a comparison between the northern and central SCS areas which had different environmental factors.There had been higher temperature but lower nutrients and chlorophyll a concentrations in the central SCS than those in the northern SCS.The mean rates of phytoplankton growth(μ0)and microzooplankton grazing(m)were(0.88±0.33)d–1 and(0.55±0.22)d–1 in the central SCS,and both higher than those in the northern SCS with the values ofμ0((0.81±0.16)d–1)and m((0.30±0.09)d–1),respectively.Phytoplankton growth and microzooplankton grazing rates were significantly coupled in both areas.The microzooplankton grazing impact(m/μ0)on phytoplankton was also higher in the central SCS(0.63±0.12)than that in the northern SCS(0.37±0.06).The microzooplankton abundance was significantly correlated with temperature in the surface.Temperature might more effectively promote the microzooplankton grazing rate than phytoplankton growth rate,which might contribute to higher m and m/μ0 in the central SCS.Compared with temperature,nutrients mainly affected the growth rate of phytoplankton.In the nutrient enrichment treatment,the phytoplankton growth rate(μn)was higher thanμ0 in the central SCS,suggesting phytoplankton growth in the central SCS was nutrient limited.The ratio ofμ0/μn was significantly correlated with nutrients concentrations in the both areas,indicating the limitation of nutrients was related to the concentrations of background nutrients in the study stations.

传染率季节性和流动人口对麻疹动态的影响

为分析传染率季节性和流动人口对于河南省的麻疹动态的影响,比较分析麻疹的传染率季节性变化模式,对中国麻疹的未来防控提供理论支持。建立了包含流动人口和传染率季节性阶梯模型的SIR模型,使用马尔科夫蒙特卡洛方法估计模型中的参数,比较本地流动人群和省外流动人群的传染率,分析不同传染率模型对传播动态的影响。在河南的麻疹传播动态中,省外流动人群对麻疹传播动态的影响大于本地人群,河南传染率季节性变化模式更符合阶梯变化,流动人口对于河南麻疹传播动态的影响高于传染率季节性。在未来的麻疹防控工作中应该加强对流动人口的监测,合理选择免疫接种时间和人群。

NW Indian Ocean’s SSTs Are Bi-Seasonal

Two independent atlases agree that in the northwest Indian Ocean the sea surface temperatures cool down markedly in the spring and also that they have a significant double seasonal cycle, unlike any other ocean in both cases. Horizontal advection is proposed to play an important part in causing these unusual features to occur.

Changing Spring Phenology Dates in the Three-Rivers Headwater Region of the Tibetan Plateau during 1960–2013

The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season(SOS)based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer–Normalized Difference Vegetation Index data for 2000–13. We then reconstruct the SOS time series based on the temperature data for 1960–2013.The regional mean SOS shows an advancing trend of 1.42 d(10 yr)during 1960–2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d(10 yr)during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d(10 yr)] during 2000–13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region,during 2000–13.

Assessment of Spring Water Quality in the Rural Watersheds of Western Nepal

A preliminary study was conducted to analyze the water quality of spring waters in rural watershed of Western Nepal. 155 spring water samples were collected from Jhimruk, Rangun, Bogtan-Lagam Karnali, Thuligad and Middle Karnali watershed. Collection and analysis occurred twice, once in pre-monsoon 2018 and post-monsoon 2018. Various physical and chemical parameters were analyzed by using standard water quality measurements and compared with the Nepal Drinking Water Quality Standard and the World Health Organization Standard Guideline. The results indicate that the turbidity was high during pre-monsoon season. The highest turbidity of 63.8 NTU was observed in the Bogtan-Lagam Karnali watershed. Two spring sources—one in Bogtan-Lagam Karnali and one in Middle Karnali exceeded the health standard for nitrate-N. The phosphate levels were high during the pre-monsoon season in Jhimruk and Rangun watershed in all the studied sites. Dissolved oxygen levels were relatively high during post-monsoon season. Results of the water quality index in all the studied sites revealed that the water quality ranges from being poor to good conditions in the spring sources. The results from this study suggested that the water bodies are relatively good and can be used for domestic purposes after suitable treatment.

基于屈服装置-碟簧系统的双向调节预应力锚索

川藏交通廊道规划路线沿线滑坡锚固工程在全生命周期内将不可避免受到季节性冻土冻胀融缩的不利影响。为减缓此不利影响,本文提出基于多个挤压摩擦型屈服套的屈服装置、消能蓄能型碟簧系统,形成可双向调节预应力的锚索新结构。并对该锚索进行室内张拉试验、极限承载力试验及工作机理研究,成功研制吨位500 kN级、行程100 mm的双向调节预应力锚索。室内试验证实,单个挤压摩擦型屈服套起始屈服力为120~135 kN,平稳行程可达255 mm;屈服装置由4个挤压摩擦型屈服套及P锚组成,起始屈服力为420~450 kN,行程可达到100 mm以上;碟簧系统可实现耗能(冻胀时可抵消约60%的预应力增长)与蓄能(融缩时可抵消约40%的预应力损失)的目的。屈服行程完结后,双向调节预应力锚索极限承载力为1050 kN,与传统锚索极限承载力相当。该新型锚索起始屈服力及行程具有较好的可拓展性,性能参数优于市场同类产品,可用于冻融环境及地震、大变形情形下的滑坡边坡加固,为川藏交通廊道沿线季节性冻土区滑坡、边坡防护提供了一种新的解决方案。

2000~2021年中国沙尘传输路径特征及气象成因分析

通过统计中国673个沙尘观测站点的地面资料,并结合气象条件分析,确定了北方地区沙尘天气的演变规律和传输特征,以及气象要素变化影响.结果表明:2000~2021年中国北方沙尘天气过程的发生频次及强度总体呈现下降趋势.春季沙尘事件占比达到77.8%,其中近40%出现在4月,显著高于其它月份.在五种典型沙尘传输路径中,西北路径型、偏西路径型和偏北路型最为主要,其比重分别为38.5%、32.9%和18.2%.同时,春季沙尘的输送路径具有阶段性分布特点,具体表现为2000~2006年以西北路径为主,2007~2013年为过渡期呈现偏西路径增多西北路径减少的态势,直至二者比例相当,2014~2021年则调整为以偏西来向为春季沙尘天气的主要传输路径.此外,气象分析表明,近年来春季气候已转为“暖湿型”,东亚沙尘整体趋于减弱.但亚洲极涡中心逐渐西移北抬、移至新地岛以东地区,西北亚与中亚之间存在较强海平面气压差,境内西北地区中东部主要沙源地低层风速持续增大,均有利于偏西路径型沙尘天气的产生.

蒙古国冬春季气候非对称变暖及其对植被返青期和春季NDVI的影响

基于2001—2020年NDVI和EVI两种遥感植被指数及蒙古国60个气象站点的气温和降水数据,利用累积植被指数的Logistic曲线曲率极值法和动态阈值法提取蒙古国植被返青期,并结合偏相关分析方法探讨二者与冬春季昼夜气温非对称变化之间的关系。结果表明:(1)近20 a来,最高气温在冬春季的变暖速率分别为0.07℃·a^(-1)、0.15℃·a^(-1)(P<0.05,R^(2)=0.33),最低气温在冬春季的变化速率分别为-0.01℃·a^(-1)、0.04℃·a^(-1),冬春季气温日较差的变化速率分别为0.08℃·a^(-1)、0.11℃·a^(-1)(P<0.05,R^(2)=0.52),存在明显的季节性差异。(2)蒙古国植被返青期对冬春季气候变暖的季节性响应是非对称的,冬季最高气温和气温日较差的影响大,而春季则是最低气温影响大,且均表现为负相关。(3)蒙古国气候变暖对植被NDVI产生的非对称影响主要表现在春季,即春季最高气温和气温日较差对植被NDVI主要表现为负相关,而春季最低气温对植被NDVI主要表现为正相关。研究结果可为进一步了解全球气候变暖背景下植被春季物候及植被后期生长的季节性影响提供重要参考价值。

北京东灵山森林木本植物物候对气温响应的季节差异

[目的]明确北京东灵山暖温带森林木本植物不同物候期对气候变暖响应的季节性差异。[方法]本文利用2003-2019年北京市暖温带森林24种木本植物的6种物候期数据,采用偏最小二乘回归和相关分析计算各物候期对季节气温响应的最优相关时段,并应用Wilcoxon符号秩检验对比各物候期对相关时段内气温响应敏感度的差异。[结果]展叶始期、始花期和盛花期对气温响应的最优相关时段分别为物候期前48、64、55 d(3月上中旬至4月底、5月上中旬),该时段内气温每升高1℃,始花期平均提前6.38 d,显著高于展叶始期(提前4.52 d)和盛花期(提前5.05 d)。萌芽期对气温的响应方式与上述3种物候期不同,其最优相关时段为秋冬季10月28日至下一年1月14日,其次是冬春季3月11日至4月14日(萌芽期前34 d)和夏季7月14日至8月27日。秋冬季相关时段气温每上升1℃,萌芽期提前5.48 d,显著高于冬春气温使其提前的天数(3.71 d),而夏季气温上升1℃使萌芽期推迟9.74 d,与其他均显著不同。与普遍的观点不同,叶变色期和落叶期对气温响应的最优相关时段为春夏季4月初至7月中下旬,而对夏秋季(8月下旬至9月中下旬)气温响应显著的物种很少。在气温上升1℃的情况下,春夏季相关时段气温使叶变色期和落叶期分别提前7.12和9.55 d,而夏秋季气温使其分别推迟2.27、5.96 d。近50年,研究点冬末春初(2、3月)气温的上升速度是其他月份的2倍以上,而秋冬季(10—12月)气温无显著变化。[结论]北京东灵山森林木本植物各物候期对不同季节气温的响应方式和强度具有显著差异,且各季节气温的变化呈现不一致性,这可能会对从植物个体到生态系统的各个层次都产生深刻的影响。

松浦友久对中国古典诗歌“春秋”意识及诗情谱系的考察

松浦友久以中国古典诗歌中的“四季”时间意识为显示“诗歌与时间”关系的典型之例,于诸多与四季相关的诗歌中发现中国古典诗歌侧重“春秋”意识这一文学现象,继而从诗情谱系、语汇语法、字源等方面探讨了春与秋时间意识的优先性,并穿插中日学者相关研究成果进行对比研究。松浦友久充分运用溯本探源和多学科结合的方法,以异域学者的视角,深入剖析中国古典诗歌中的“春秋”意识,在拓宽“诗歌与时间”这一论题研究路径的同时,凸显出了不同于中国本土和日本学界的独特之处。

水温和营养盐增加对太湖冬、春季节藻类生长的影响

为探讨水温和营养盐增加对冬、春季节太湖藻类生长和群落演替的影响,研究了不同水温（不增温、12.0、14.0、16.0、18.0、20.0℃）和不同营养盐浓度（低、中、高营养盐浓度）下藻类的生长及优势种群变化. 结果表明：藻类∑ρ（Chla）〔蓝藻、绿藻及硅藻中ρ（Chla）总量,下同〕随着水温的升高呈增加趋势,在20.0℃下∑ρ（Chla）为0.19-12.94μgL,显著高于其他水温试验组（0.01-6.83μgL）；与较低水温（不增温、12.0、14.0℃）相比,较高水温（16.0、18.0、20.0℃）更能显著促进藻类对氮、磷营养盐的吸收利用. 添加营养盐后,硅藻、绿藻ρ（Chla）的日均值分别为0.52-4.07、0.17-0.52μgL；湖水中∑ρ（Chla）呈增长趋势,并且浮游植物群落结构的优势种由绿藻转变为硅藻,硅藻ρ（Chla）所占比例从试验初始的50%升至75%-98%, 说明营养盐增加可加大硅藻的竞争优势；而绿藻的生长则可能同时受水温和营养盐共同作用的影响,因此太湖冬、春季节藻类的演替同时受到水温和营养盐的影响.

春季禁渔期间长江下游鱼虾蟹类物种多样性变动(2001-2004年)

长江春禁期4-6月间,下游江段渔获中出现鱼、虾、蟹共12目、30科、81种.安徽、江苏江段年间物种多样性指数明显上升并趋于稳定,其中Shannon—Wiener(H’与H”)在1.593—2.563范围内呈上升并趋于稳定、Margalef在0.866—2.755范围内呈明显上升、Pielou、Simpson和McNaughton指数在窄幅波动中趋于稳定,波动范围分别为0.717—0.827;0.120—0.269;0.365—0.616.河口区多样性指数正处于波动中,Simpson和McNaughton指数分别从0.195升至0.315;从0.534升至0.758,并有继续上升的趋势.各江段年间捕捞证发放数与ShannonH’的回归分析表明两者呈负相关线型关系.

黄河三角洲典型地区春季土壤水盐空间分异特征研究--以垦利县为例

黄河三角洲作为我国重要的后备土地资源区,土壤盐渍化问题突出,切实掌握土壤水盐状况及其空间规律是该区土壤盐渍化防控和土地资源高效利用的重要基础。本研究选择黄河三角洲垦利县,通过野外调查实测与室内化验分析获取土壤水盐含量数据,利用统计分析、GIS插值、缓冲区分析等方法,分析了研究区土壤水盐状况及其空间变异规律。结果显示:研究区总体盐分含量以中度为主,含盐量由表层至底层呈上升趋势,且各层土壤含盐量呈显著正相关性;含盐量较高的地区主要分布在县域东部滨海区,含盐量较低的地区主要分布在该县的西南部;土壤含盐量随着距离渤海渐远呈下降的趋势,含水量总体呈先下降后上升趋势;从黄河向两岸延伸,土壤含盐量均随距离黄河渐远呈上升的趋势,含水量呈先下降后上升趋势;土壤含盐量从大到小的不同植被类型依次为光板地>碱蓬>柽柳>马绊草>芦苇>茅草>水稻>棉花>小麦>玉米;土壤含盐量从大到小的不同地貌类型依次为洼地>微斜平地>缓岗>河滩高地。该研究基本摸清了研究区春季时相的土壤水盐状况及空间变异规律,为黄河三角洲土壤资源可持续利用提供了科学依据。

春季我国东部海洋温度锋区对大气的强迫作用及其机制研究

首先,采用高分辨率的卫星资料研究了春季我国东部海区海洋锋区附近的海温与风场之间的关系,资料分析表明海温与海表面风速之间存在明显的正相关关系,特别是在海洋锋强的年份,这种正相关关系更明显。资料分析还表明春季是黄海、东海海洋锋最强的季节,海温与海表面风速的对应关系在春季尤为明显。然后,采用一个高分辨率和先进物理方案的中尺度模式探讨了海洋影响大气的机制。控制试验再现了海洋锋区附近海温与海表面风速之间的正相关关系。模拟的边界层垂直结构说明海温能够明显改变锋区两侧边界层大气的稳定度和垂直混合的强弱,证明了垂直混合机制的存在。而另一方面,对控制试验和平滑海温试验的水平动量方程中各收支项的比较分析发现,由于海洋锋的存在而产生的气压梯度力对穿越锋区的空气的加速也有相当重要的贡献。综合观测和模拟结果说明春季我国东部海区海洋温度锋区的海洋—大气相互作用过程中海洋对大气的影响非常明显,在海洋影响大气的机理方面,海平面气压调整机制和垂直混合机制都在起作用。

新疆北疆地区某集约化肉牛养殖场春季环境指标评价

为了解新疆伊犁地区昭苏县肉牛养殖环境状况，评价其环境质量，本研究对该县某典型集约化肉牛养殖场的相关环境指标进行了测定。采用DT-8820四合一多功能环境表（光照强度、温度、湿度、噪音）、智能气体检测报警仪（二氧化碳（CO2）、氨气（NH3）、甲烷（CH4））和LD-5C微电脑激光粉尘仪（可吸入颗粒物（PMl0）和总悬浮颗粒物（TSP））对新疆昭苏县某集约化肉牛养殖场肉牛舍春季（4月下旬）上述环境指标进行为期10d的测定。结果表明，该牛舍春季每天采光时间为08：00～18：00，约10h；光照强度、温度、湿度和噪音平均值分别为105．61 Lux、16．30℃、49．56％和64．59dB；CH4、C02和NH3浓度平均值分别为0．09、880．91和0．51mg／m^3；PMl0和TSP浓度平均值分别为0．030和0．010mg／m^3。通过对上述指标的日周期和时周期变化可发现牛舍平均温度超过国标最高限值，持续时间为11：00～24：00，约13h。综上所述，除牛舍温度指标外，该牛舍测定的各项环境指标参数均符合畜禽养殖环境标准，该牛舍春季环境较适宜肉牛生产，但需要采取相应措施对牛舍温度进行调节以保证动物的福利需求。

长江春季禁渔对崇明北滩渔业群落的影响

对1999至2005年每年的4～6月间崇明北滩渔业群落进行研究，对春季禁渔前后相关指标进行对比分析。实施长江春季禁渔前，崇明北滩渔业群落组成为11目、19科、25属、27种。实施长江春季禁渔后，该群落共出现鱼虾蟹等渔业生物30种，分别隶属于9目18科26属。群落优势种为凤鲚[Coilia mystus（Linnaeus）]、棘头梅童鱼[Collichthys lucidus（Richardson）]、红狼牙鰕虎[Odontamblyopus rubicundus（Hamilton-Bnchanan）]和狭颚绒螯蟹[Eriochier leptognathus（Rathbun）]，单位质量小于20g的小型种类占绝对优势，鱼类幼体所占比例极大。多样性特征值平均指标为：Margalef指数1．50，Wilhm改进指数1．83，Simpson指数0．24，Pielou指数0．72。实施春季禁渔后该群落组成变化显著，复杂程度有所下降，多样性特征值仍大幅度波动，企稳回升趋势不明显。结果显示，春季禁渔对该群落的保护作用尚不明显，针对该群落的保护工作应进一步加强。

拉萨藏雪鸡春季栖息地选择

2005年3—4月,在拉萨曲水县雄色寺周围山上的灌丛地,对藏雪鸡栖息地选择,通过调查和测量与其有关的14个参数,发现雪鸡喜欢在灌丛盖度较低、距离民居近的地方觅食,并喜欢在灌丛盖度较低、草本种类较少、草本盖度较低、岩石较多、距民房距离较近的地方休息。另外还发现,人类保护和投食对雪鸡栖息地选择也有很大的影响。调查结果显示,研究地区的雪鸡活动在很大程度上依赖人类活动。

旱地全膜覆土穴播对春小麦耗水、产量和土壤水分平衡的影响

目的干旱、降水供需错位和春季低温是制约西北黄土高原丘陵沟壑区春小麦生产的主要因子,如何最大限度保蓄自然降水、实现水分的跨季节利用,则是该区春小麦产量稳定提高的根本途径。本文在大田定位观测的基础上,揭示全膜覆土穴播对西北黄土高原旱作春小麦季节性耗水特征、产量、水分利用效率和休闲期土壤水分补给的影响,并评判其年际土壤水分平衡效应。方法试验于2011—2013年在西北黄土高原半干旱区的甘肃省农业科学院定西试验站进行(104°36′E,35°35′N),以春小麦陇春27号为试验材料,设全膜覆土穴播(FMS)、地膜覆盖穴播(FM)和露地穴播(CK)3个处理,测定春小麦不同生育时期的土壤含水量、生物量、产量和产量构成因子,计算休闲效率、耗水量、水分利用效率、收获指数等指标。结果 2011和2012年3个处理的春小麦耗水量无显著差异,但2013年FMS耗水量显著高于CK。FMS和FM可增加春小麦苗期到孕穗期耗水,且此阶段的耗水量在干旱年份分别较CK增加27.2%和9.6%,在丰水年份分别较CK增加52.2%和44.6%。虽然FMS和FM在各生育期的耗水量无显著差异,但FMS在丰水年(2012年和2013年)的耗水量较FM有增加趋势,且这一效果在2013年尤为明显。FMS和FM在休闲期可补充0—80 cm土层土壤水分25.4和18.3 mm,比CK分别低2.2和9.3 mm;补充80—200 cm土层土壤水分78.0和71.0 mm,比CK分别高30.0和23.1 mm;与2011年播前相比,种植3年春小麦后0—200 cm土层的土壤贮水量FMS增加了23.8 mm、FM增加了22.5 mm、CK增加了12.4 mm。FMS的休闲效率为30.5%—52.6%,比CK高12.8%—109.5%,比FM高4.5%—40.9%。FMS的穗粒数、千粒重等产量构成因子均显著高于CK(P<0.05);收获指数为0.4—0.5,比CK高32.5%。FMS的产量为1 750—3 180 kg·hm-2,水分利用效率为5.5—11.5 kg·hm-2·mm-1,分别比CK增加40%—220%、27%—239%,而且干旱年份的增加幅度更高。在干旱的2011年,FMS处理的产量较FM增加26.2%,水分利用效率提高28.2%;在丰水的2013年,FMS处理的产量较FM增加20.9%,水分利用效率提高14.8%,两年均达到显著差异水平,表明FMS较FM具有更明显的丰水年份增产、干旱年份适应干旱胁迫的潜力,能够实现该区春小麦生产稳产高产的目标。结论西北黄土高原半干旱区FMS种植模式有效提高了春小麦播前和生长前期的土壤贮水量,并使春小麦苗期—孕穗期的作物耗水量显著升高,增加春小麦穗粒数,扩大籽粒产量库容和促进灌浆,显著提高春小麦产量和水分利用效率;并在休闲期完全补充春小麦生育期消耗的0—200 cm土壤水分,保持春小麦田的土壤水分年际平衡。