基于遥感ET数据的区域水资源状况及典型农作物耗水分析

以遥感ET及实测降水数据为基础,借助GIS技术开展水分盈亏分析研究;同时依据项目区土地利用现状,选择冬小麦、夏玉米、棉花及人工草坪为重点分析对象,对其耗水及灌溉耗水规律进行研究。结果表明:①大兴区耗水量与降水量在总量上不平衡,时空上不匹配,在现状土地利用下若无外来水补充,则不得不超采地下水,资源型缺水突出。②冬小麦和夏玉米耗水年际变化不大,而棉花及人工草坪随降水增加耗水增大;分析作物耗水与降水的吻合性发现,冬小麦耗水与降水匹配性最差,其次为人工草坪,而夏玉米及棉花耗水与降水匹配较好。③在所选择的4种作物中小麦灌溉耗水量最大,达230 mm以上;其次为人工草坪,其灌溉耗水量超过189 mm;夏玉米及棉花灌溉耗水量较小。     

微喷带施肥灌溉对小麦玉米产量和水肥利用的影响

在2013-2015年两个连续的冬小麦-夏玉米生育期内,选用带宽为65 cm的双翼型微喷带,底肥(种肥)选用控失肥,总施肥量为当地地面灌溉高产推荐施肥量的70%,作物生育季当20 cm深度土壤基质势降低到-40 kPa时进行施肥灌溉,因夏玉米生育期正值雨季,除播种后灌溉,大喇叭口期和花粒期主要采用微喷带进行追肥。试验结果表明:①微喷带施肥灌溉水肥一体化可分别提高冬小麦和夏玉米的产量7.9%和17.1%;②冬小麦总耗水量平均为439.6 mm。整个生育期灌水量所占的比例最大,平均为36.4%,其次是土壤储水量的消耗量(35.6%),降水量占总耗水量的23.7%,地下水的补给量占的比例最小,仅4.3%。冬小麦水分利用效率平均达到1.7 kg/m~3,提高了21%。0～50 cm土壤储水量的消耗量占整个土层土壤储水量的消耗量最大,高达40%。③冬小麦和夏玉米的灌溉水利用效率分别平均为4.5和13.8 kg/m~3,分别提高了103%和62%,N和P的肥料偏生产力分别均提高了58%和67%。土壤养分主要分布在0～40 cm土层内,100～140 cm土层硝态氮含量降低了92%,显著减少了养分淋失,有效提高了肥料利用效率。因此华北平原地区微喷带施肥灌溉可提高冬小麦夏玉米的产量、水分利用效率、灌溉水利用效率和肥料利用效率。     

西辽河平原主要作物耗水量及耗水规律研究

根据联合国粮农组织推荐的Penman-Monteith公式及单作物系数法,研究了西辽河平原不同典型年的春玉米、春小麦、谷子、大豆、甜菜5种作物的耗水量及耗水规律,并分析作物生育期有效降雨量与作物耗水量的关系。计算结果表明:以一般年为例,春玉米、春小麦、谷子、大豆和甜菜的耗水量分别为501.01、427.68、464.76、443.10、500.22mm;干旱年份作物的耗水量较大,一般年次之,湿润年作物耗水量最小;作物在发育期和生育中期耗水量较大,为需水的关键时期;作物整个生育阶段有效降雨量总体上不能满足作物的耗水量,在干旱年、一般年、湿润年平均有效降雨量分别占作物生育期耗水量的40%、50%、70%左右,对作物必须进行合理的灌溉。     

不同灌溉条件对黄河下游引黄灌区作物水分关系的影响

在田间试验验证的基础上,利用SWAT2000模型对黄河下游引黄灌区冬小麦、夏玉米在不同灌溉条件下产量、耗水量以及水分利用效率等的时空变化进行了模拟,结果表明,冬小麦缺水情况比较严重,夏玉米生育期降水量基本能满足其耗水量的需求.灌溉对提高作物产量以及耗水量有很大的影响,然而随着灌水量的增加,作物产量以及耗水量增加的幅度并...     

华北平原保护性耕作生态与经济效益研究分析

<正>华北平原是中国粮食的主要生产基地之一,以冬小麦和夏玉米轮作为主,生产了约全国32%的玉米和75%的小麦。虽然该地区粮食产量占全国粮食产量的30%以上,但是其水资源矛盾日益突出。华北平原冬小麦和夏玉米双熟制的作物需水量高达800—900毫米,而华北平原年平均降水量仅为500—600毫米,尤其是在冬小麦生长的10月至翌年6月,小麦全育期平均降雨量为100—120毫米,     

不同灌水方式根层土壤水分动态及耗水规律试验研究

通过冬小麦、夏玉米周年连作种植试验,观测不同灌水方式根层土壤水分的动态变化,揭示了不同灌水方式和土层深度土壤含水率的变化规律,建立不同时期、不同土层的土壤水含量变化曲线,进而研究出冬小麦、夏玉米不同生育阶段的耗水规律。结果表明:夏玉米生育期土壤含水量波动较冬小麦频繁,周年内,水分处理越高,土壤含水量波动越大,0~20cm土层内土壤含水率波动频率大,且波动幅度也较大,随着土层加深,土壤含水量波动减小;两种作物都是拔节期到灌浆期耗水量最大,约占全生育期耗水量的45%~50%;与传统畦灌模式相比,沟灌各水分处理的耗水量减少38.15~44.13mm,水分利用效率提高9.17%~22.73%。其中L-70处理的产量较高,耗水量适度,水分生产效率最高,小麦、玉米分别平均达到1.84、1.81kg/m3,满足节水高产的宗旨。     

华北平原冬小麦-夏玉米作物亏缺水量空间分布研究

以华北平原区20个代表性观测区域为基础,选取1996-2015年的20年完整观测序列的气象资料作为分析对象,对华北平原区传统种植作物冬小麦-夏玉米设计典型年下生长期的作物亏缺水量进行计算,通过经验频率法确定了降水频率分别为75%、50%、25%的设计典型年及相应的降水量,计算确定参考作物腾发量,结合冬小麦、夏玉米的作物系数得出作物需水量,进而计算出设计典型年下作物亏缺水量,基于ArcGIS对华北平原整个地区的水分亏缺量进行了插值,绘制亏缺水量等值线图。为合理制定灌溉制度、调整农业作物种植结构以及优化农业水资源配置提供参考依据。     

运城市主要粮食作物灌溉需水量时空变化研究

明确运城市主要粮食作物冬小麦和夏玉米灌溉需水量的时空变化规律,为未来该市灌溉用水的科学配置提供基本参数。基于运城市域内13个气象站点的长期观测资料,利用Penman-Monteith公式确定参考作物蒸散量,结合有效降雨量和作物系数等参数,计算分析了运城市近50 a冬小麦与夏玉米的灌溉需水量及其时空变化特征。结果表明：在研究时段内,冬小麦和夏玉米年灌溉需水量整体均呈现波动式降低的变化趋势,整体降低幅度分别为-0.7和-2.1 mm/(10 a)。冬小麦在4月和5月的灌溉需水量较多,分别为80.5 mm和108.4 mm;夏玉米则为8月份的灌溉需水量最大,约为85.3 mm。冬小麦和夏玉米全生育期的平均灌溉需水量都呈现从东向西逐渐递增的趋势,冬小麦灌溉需水量的变化范围处于283.6～336.8 mm,夏玉米则为165.4～253.9 mm。相关分析结果表明,水汽压差与太阳辐射对运城市冬小麦和夏玉米灌溉需水量的影响较大。运城市冬小麦与夏玉米灌溉需水量在时间上呈波动降低趋势,在空间上则由东向西逐步递增;气温与降水的变化趋势显示运城市的气候正在朝暖湿化方向发展,未来灌溉方案的制定与优化应当予以充...     

降水对华北主要粮食作物灌溉需求影响特征

探明华北地区作物灌溉需求规律及主控因素是合理制定水资源规划,缓解该区地下水超采的重要依据。本文基于华北60个气象站近50年(1971—2020年)逐日气象资料,采用FAO推荐的Penman-Monteith公式计算作物需水量,并分析降水对主要粮食作物(冬小麦和夏玉米)灌溉需求时空特征的影响。结果表明：在降水丰水年(25%),冬小麦作物灌溉需求指数I_RI以0.50～0.75区间的高度灌溉需求分布区为主,夏玉米则以0.25～0.50区间的中度灌溉需求分布区为主,分布面积比率分别为研究区的92%、86%;在平水年(50%),冬小麦I_RI以大于0.75的极高灌溉需求分布区为主,分布面积比率占56%,夏玉米仍以0.25～0.50的中度灌溉需求分布区为主,但分布面积比率扩大至100%;在枯水年(75%),冬小麦极高灌溉需求分布面积比率增大至97%,夏玉米则以0.50～0.75的高度灌溉需求分布区为主。降水量是影响I_RI的主控因素,随降水量的增大,不同区位I_RI均呈直线下降趋势,但对降水量变化的敏感性存在较大差异...     

旱作农业呼唤覆膜穴播机械

占我国国土面积53％的干旱、半干旱地区，因降水量少，水资源严重不足．因而绝大多数为旱作农业．更有相当一部分为南养农业．特别是山区和丘陵地带．完全为雨养农业。在雨养农业地区．每年仅有的300mm左右的降雨量又集中于7、8、9三个月．在冬小麦生长期内的冬春季节，因降雨量稀少而远不能满足其生长的需要。另外．在夏地瓜、冬小麦，夏玉米、冬小麦轮作区．不仅因水资源不足而严重影响产量．也因为光照不足．土壤年积温过低而使作物生长期不足产生争茬现象，造成作物减产或因不能适时播种而使土地荒置。冬小麦实施覆膜穴播，可较好地解决…     

Effect of precipitation change on water balance and WUE of the winter wheat-summer maize rotation in the North China Plain

Limited precipitation restricts crop yield in the North China Plain, where high level of production depends largely on irrigation. Establishing the optimal irrigation scheduling according to the crop water requirement (CWR) and precipitation is the key factor to achieve rational water use. Precipitation data collected for about 40 years were employed to analyze the long-term trend, and weather data from 1984 to 2005 were used to estimate the CWR and irrigation water requirements (IWR). Field experiments were performed at the Luancheng Station from 1997 to 2005 to calculate the soil water consumption and water use efficiency (WUE). The results showed the CWR for winter wheat and summer maize were similar and about 430 mm, while the IWR ranged from 247 to 370 mm and 0 to 336 mm at the 25% and 75% precipitation exceedance probabilities for winter wheat and summer maize, respectively. The irrigation applied varied in the different rainfall years and the optimal irrigation amount was about 186, 161 and 99 mm for winter wheat and 134, 88 and 0 mm for summer maize in the dry, normal and wet seasons, respectively. However, as precipitation reduces over time especially during the maize growing periods, development of water-saving management practices for sustainable agriculture into the future is imperative.     

滇东北作物耗水特性及影响因素

基于滇东北地区3个气象站点(会泽站、昭通站、沾益站)1955-2013年逐日气象资料,采用FAO-56 Penman-Monteith公式,计算并分析滇东北地区水稻、春玉米和冬小麦全生育期需水量及其变化趋势,同时采用偏相关分析和逐步回归分析探讨各气象因子对主要粮食作物需水量影响的程度.结果表明:昭通站主要粮食作物需水量随时间呈不同程度减少,每10 a水稻需水量减少10.07 mm,春玉米减少1.44 mm,冬小麦减少1.06 mm.而其他站点呈增加趋势,水稻需水量每10 a分别增加8.85,4.48 mm,春玉米分别增加8.38,4.57 mm,冬小麦分别增加7.39,3.10 mm.3个站点同一种作物各生育阶段需水量规律基本一致,水稻各生育期需水量从大到小依次为:分蘖,拔节,抽穗,乳熟,黄熟,返青;玉米的依次为:拔节,灌浆,苗期,孕穗,成熟;小麦的的依次为:乳熟,开花,成熟,苗期.日照和平均风速是影响水稻和玉米需水量最主要的气象因子,且呈显著正相关关系,就各站点而言,影响冬小麦需水量的气象因子存在差异,其中会泽站和沾益站同日照时数和平均气温呈显著正相关,而昭通站与平均湿度呈显著负相关,同日照时数呈显著正相关关系.     

基于田间实际耗水的作物生产水足迹

为了衡量田间尺度粮食生产对资源的真实利用,基于水足迹及作物耗水理论,提出基于作物实际耗水的农作物生产水足迹计算方法,并以陕西关中的小麦、玉米为研究对象,对1998,2005及2010年的生产水足迹进行了计算.结果显示：同一年份同一作物不同地区间耗水量具有较大差异,同时,关中地区3个代表年份平均小麦、玉米耗水量分别比需水量小16.2%和12.4%;小麦、玉米生产水足迹有减小趋势,代表年平均值分别为0.96,0.77 m^3/kg;各地区小麦虚拟水中蓝水比例在10%-40%,玉米则在20%-50%范围内变化,且年际、地区间的蓝水占有比例均无明显变化趋势;3个代表年小麦、玉米的总水足迹之和分别为70.1,59.8及60.7亿m3,均大于当地的水资源总量,其中蓝水所占比例均值为29.1%.基于作物实际耗水的作物生产水足迹的计算对基于水足迹和虚拟水贸易的科学研究及政策制定均有重要意义.     

Simulation of water dynamics and irrigation scheduling for winter wheat and maize in seasonal frost areas

Continuous cropping of winter wheat and summer maize is the main cropping pattern in North China Plain lying in a seasonal frost area. Irrigation scheduling of one crop will influence soil water regime and irrigation scheduling of the subsequent crop. Therefore, irrigation scheduling of winter wheat and maize should be studied as a whole. Considering the meteorological and crop characteristics of the area lying in a seasonal frost area, a cropping year is divided into crop growing period and frost period. Model of simultaneous moisture and heat transfer (SMHT) for the frost period and model of soil water transfer (SWT) for the crop growing period were developed, and used jointly for the simulation of soil water dynamics and irrigation scheduling for a whole cropping year. The model was calibrated and validated with field experiment of winter wheat and maize in Beijing, China. Then the model was applied to the simulation of water dynamics and irrigation scheduling with different precipitation and irrigation treatments. From the simulation results, precipitation can meet the crop water requirement of maize to a great extent, and irrigation at the seeding stage may be necessary. Precipitation and irrigation had no significant influence on evaporation and transpiration of maize. On the other hand, irrigation scheduling of winter wheat mainly depends on irrigation standard. Irrigation at the seeding stage and before soil freezing is usually necessary. For high irrigation standard, four times of irrigation are required after greening. While for medium irrigation, only once (rainy year) or twice (medium and dry years) of irrigation is required after greening. Transpiration of winter wheat is very close for high and medium irrigation, but it decreases significantly for low irrigation and will result in a reduction of crop yield. Irrigation with proper time and amount is necessary for winter wheat. Considering irrigation quota and crop transpiration comprehensively, medium irrigation is recommended for the irrigation of winter wheat in the studying area, which can reduce the irrigation quota of over 150 mm with little water stress for crop growth.     

1957-2017年京津冀主要作物水分利用效率及节水潜力分析

水资源短缺以及农业用水效率不高制约着京津冀一体化国家战略的实施。【目的】提高主要作物水分利用效率,缓解京津冀地区农业水资源矛盾。【方法】基于FAO推荐的Penman-Monteith公式及有效降水计算公式估算了1957-2017年京津冀地区冬小麦、夏玉米的耗水量及水分利用效率以及冬小麦、夏玉米的节水潜力。【结果】冬小麦、夏玉米水分利用效率呈逐年线性增长趋势。冬小麦、夏玉米水分利用效率仍有20%~30%的提升空间,在产量不变的前提下,京津冀地区可节约水量43.6亿~60.4亿m^3。冬小麦节水潜力高于夏玉米。【结论】可通过改善土壤条件,优化灌溉管理以及秸秆覆盖等措施提高冬小麦及夏玉米的水分利用效率。     

气候变化对黑河流域典型作物灌溉需水量的影响

为研究气候变化对作物灌溉需水量的影响,在假定未来气温上升0.5~4℃,降水增加10%~30%的条件下,研究了黑河流域主要作物在不同种植条件下的作物需水量及灌溉需水量的变化。结果表明,生长期内气温每升高1℃,区域内小麦净作、玉米净作和小麦与玉米间作方式下作物需水量将分别增加3.1%(15.5 mm)、2.8%(18.5 mm)和3.0%(25.6 mm),黑河流域中游每年将增加灌溉量0.15×108m3,相当于国家给黑河干流区分水量的2.4%;降水每增加10%,灌溉需水量将分别减少1.9%(7.8 mm)2、.3%(12.4 mm)和1.8%(12.8 mm)。     

气候变化对区域农业灌溉用水影响分析

从气候变化对区域灌溉用水影响机理入手,利用区域经济发展、灌溉用水、种植结构等因素之间动态反馈关系,采用系统动力学建模方法,构建了气候变化背景下灌溉用水响应模型,分析了未来不同气候情景下宝鸡峡灌区灌溉用水的变化过程。结果表明,随着未来气温升高趋势的增加,灌溉用水亦呈明显升高趋势,不同情景稍有差异,但差别不大,而不同作物间差异较大。以B1情景为例,温度升高1℃,灌区内灌溉净需水量约增加12050×104m3,毛需水量约增加20080×104m3,灌区内小麦单位面积约增加需水量28m3/亩;玉米约增加8m3/亩,这可能与冬小麦和夏玉米生育期的变化有关,应进一步加强研究。     

An improved water use efficiency of cereals under temporal and spatial deficit irrigation in north China

Water shortage is the major bottleneck that limits sustainable development of agriculture in north China. Crop physiological water-saving irrigation methods such as temporal (regulated deficit irrigation) and spatial (partial root zone irrigation) deficit irrigation have been tested with much improved crop water use efficiency (WUE) without significant yield reduction. Field experiments were conducted to investigate the effect of (1) spatial deficit irrigation on spring maize in arid Inland River Basin of northwest China during 1997–2000; (2) temporal deficit irrigation on winter wheat in semi-arid Haihe River Basin during 2003–2007 and (3) temporal deficit irrigation on winter wheat and summer maize in Yellow River Basin during 2006–2007. Results showed that alternate furrow irrigation (AFI) maintained similar photosynthetic rate (P_n) but reduced transpiration rate (T_r), and thus increased leaf WUE of maize. It also showed that the improved WUE might only be gained for AFI under less water amount per irrigation. The feasible irrigation cycle is 7d in the extremely arid condition in Inner River Basin of northwest China and less water amount with more irrigation frequency is better for both grain yield and WUE in semi-arid Haihe River Basin of north China. Field experiment in Yellow River Basin of north China also suggests that mild water deficit at early seedling stage is beneficial for grain yield and WUE of summer maize, and the deficit timing and severity should be modulated according to the drought tolerance of different crop varieties. The economical evapotranspiration for winter wheat in Haihe River Basin, summer maize in Yellow River Basin of north China and spring maize in Inland River Basin of northwest China are 420.0 mm, 432.5 mm and 450.0 mm respectively. Our study in the three regions in recent decade also showed that AFI should be a useful water-saving irrigation method for wide-spaced cereals in arid region, but mild water deficit in earlier stage might be a practical irrigation strategy for close-planting cereals. Application of such temporal and spatial deficit irrigation in field-grown crops has greater potential in saving water, maintaining economic yield and improving WUE.