Development Potentials and Benefit Analysis of Efficient Water-saving Irrigation in Lixin County

On the basis of analyzing water resources,crop planning structure,and irrigation mode in Lixin County,potentials and benefits of developing efficient water-saving irrigation in the county were explored to provide references for its future water-saving irrigation.

The water-saving potential of using micro-sprinkling irrigation for winter wheat production on the North China Plain

The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.

What determines irrigation efficiency when farmers face extreme weather events? A field survey of the major wheat producing regions in China

Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.

Field experiments on greenhouse gas emissions and nitrogen and phosphorus losses from rice paddy with efficient irrigation and drainage management

Greenhouse gas emissions,nitrogen and phosphorous losses through ammonia volatilization,leaching and surface drainage from rice paddy under efficient irrigation and drainage were analyzed based on field experimental data in order to reveal the eco-environmental impacts of efficient irrigation and drainage on rice paddy.The results showed that total methane emission from rice paddy under the controlled irrigation was reduced by more than 80% and total nitrous oxide emission increased by 15.9% compared with flooding irrigation.Seasonal comprehensive global warming potentials(GWP) of methane and nitrous oxide were 62.23 gCO2 m-2 for rice paddy under the controlled irrigation,reduced by 68.0% compared with flooding irrigation.Due to large reduction in seepage and surface drainages,nitrogen and phosphorous losses through leaching were reduced by 40.1% and 54.8%,nitrogen and phosphorous losses through surface drainage were reduced by 53.9% and 51.6% from rice paddy under efficient irrigation and drainage compared with traditional irrigation and drainage.Nitrogen loss through ammonia volatilization was reduced by 14.0%.Efficient irrigation and drainage management is helpful to mitigate greenhouse gases emission,nitrogen and phosphorus losses and their pollution on groundwater and surface water.

Optimizing water-saving irrigation schemes for rice(Oryza sativa L.)using DSSAT-CERES-Rice model

Rice is one of the major crops in China,and enhancing the rice yield and water use efficiency is critical to ensuring food security in China.Determining how to optimize a scientific and efficient irrigation and drainage scheme by combining existing technology is currently a hot topic.Crop growth models can be used to assess actual or proposed water management regimes intended to increase water use efficiency and mitigate water shortages.In this study,a CERES-Rice model was calibrated and validated using a two-year field experiment.Four irrigation and drainage treatments were designed for the experiment:alternate wetting and drying(AWD),controlled drainage(CD),controlled irrigation and drainage for a low water level(CID1),and controlled irrigation and drainage for a high water level(CID2).According to the indicators normalized root mean square error(NRMSE)and index of agreement(d),the calibrated CERES-Rice model accurately predicted grain yield(NRMSE=6.67%,d=0.77),,shoot biomass(NRMSE=3.37%,d=0.77),actual evapotranspiration(ETa)(NRMSE=3.83%,d=0.74),irrigation volume(NRMSE=15.56%,d=0.94),and leaf area index(NRMSE=9.69%,d=0.98)over 2 a.The calibrated model was subsequently used to evaluate rice production in response to the four treatments(AWD,CD,CID1,and CID2)under 60 meteorological scenarios which were divided into wet years(22 a),normal years(16 a),and dry years(22 a).Results showed that the yield of AWD was the largest among four treatments in different hydrological years.Relative to that of AWD,the yield of CD,CID1,and CID2 were respectively reduced by 5.7%,2.6%,8.7%in wet years,9.2%,2.3%,8.6% in normal years,and 9.2%,3.8%,3.9% in dry years.However,rainwater use efficiency and irrigation water use efficiency were the greatest for CID2 in different hydrological years.The entropy-weighting TOPSIS model was used to optimize the four water-saving irrigation schemes in terms of water-saving,labor-saving and high-yield,based on the simulation results of the CERES-Rice model in the past 60 a.These results showed that CID1 and AWD were optimal in the wet years,CID1 and CID2 were optimal in the normal and dry years.These results may provide a strong scientific basis for the optimization of water-saving irrigation technology for rice.

不同灌溉模式下水稻田氮素运移规律

为了提高水稻田氮素利用率减少农业面源污染,选取了2块大田,分别采取干湿交替节水灌溉和传统淹灌方式,分析稻田土壤剖面NH_(4)^(+)-N、NO_(3)^(-)-N及TN浓度的分布规律。结果表明节水灌溉和传统淹灌条件下,施入3次氮肥后,地表水及土壤不同深度处NH_(4)^(+)-N和TN浓度变化规律相似且均会出现峰值后迅速降低。而节水灌溉条件下由于NO_(3)^(-)-N浓度太低导致峰值不明显,传统淹灌条件下的NO_(3)^(-)-N浓度峰值到达时间相比于NH_(4)^(+)-N有一定滞后性。整体来说,水稻田施肥后5 d内是防控田间氮素流失的关键时期;节水灌溉条件下水稻田的灌溉水利用效率和氮素生产率更高。此研究结果可为提高水肥利用率和减少农业面源污染等提供理论依据。

The effect of different agricultural management practices on irrigation efficiency, water use efficiency and green and blue water footprint

This paper explores the effect of varying agricultural management practices on different water efficiency indicators: irrigation efficiency(IE), crop water use efficiency(WUE), and green and blue water footprint(WF). We take winter wheat in an experimental field in Northern China as a case study and consider a dry, average and wet year. We conducted 24 modeling experiments with the Aqua Crop model, for all possible combinations of four irrigation techniques, two irrigation strategies and three mulching methods. Results show that deficit irrigation most effectively improved blue water use, by increasing IE(by 5%) and reducing blue WF(by 38%), however with an average 9% yield reduction. Organic or synthetic mulching practices improved WUE(by 4% and 10%, respectively)and reduced blue WF(by 8% and 17%, respectively), with the same yield level. Drip and subsurface drip irrigation improved IE and WUE, but drip irrigation had a relatively large blue WF. Improvements in one water efficiency indicator may cause a decline in another. In particular,WUE can be improved by more irrigation at the cost of the blue WF. Furthermore, increasing IE, for instance by installing drip irrigation, does not necessarily reduce the blue WF.

浅析挂马沟村田间高效节水灌溉工程设计

本文重点阐述了彭阳县挂马沟村的现代高效节水农业项目田间高效节水灌溉工程设计的相关内容。

波涌灌溉技术田间适应性分析

利用地面灌溉模型对波涌灌溉条件下地表水流及入渗过程进行模拟 ,在模拟结果与田间实测资料对比基础上 ,确定适宜的田间灌水参数 ,即土壤入渗强度、田块规格、田面坡度、入地流量、田间微地形等的变化范围 ,给出适合于波涌灌水方法应用的田间组合条件 ,提出波涌灌水技术对壤类土质的田间适应性 。

黄土高原西北部砂田西瓜集雨补灌效应研究

在黄土高原西北部地区对砂田西瓜的集雨补灌效应进行了研究。试验采用滴灌方式 ,设 0 mm (D0 )、2 2 .5mm(D1 )、45.0 mm(D2 )和 67.5mm(D3 ) 4个灌水量处理。区组内各处理随机排列 ,四次重复。试验结果表明 :在西瓜全生育期 ,每个处理 0～ 1 2 0 cm土层的土壤水分含量均呈下降趋势 ,下降的幅度随着补灌量的增加而减小。全生育期补灌 67.5mm的处理土壤含水量最高 ,比没有补灌的对照处理高 2 .2 %。土壤水分的变化在 0～ 40 cm土层比较活跃 ,其次是 40～ 80 cm土层 ,而 80～ 1 2 0 cm土层的含水量变化相对比较稳定。对砂田西瓜进行补灌可以提高产量和水分利用效率。补灌 45mm和 67.5mm的处理比对照分别增产36.3%和 45.7%。补灌 67.5mm处理的水分利用率最高 ,为 2 6.7kg/ m3 ,比对照增加 1 7.0 % ;该处理的净利润和每单位 (m3 )水的净利润也最高 ,分别达 43.677元 / hm2 和 1 8.48元 / m3 ,比不补灌的对照处理高2 9 .9%和 1 5.3%。补灌量对西瓜的含糖量也有影响 ,补灌量低于 45mm,各处理之间含糖量的差异不大 ,补灌量为 67.5mm,西瓜含糖量降低 0 .44%。补灌对西瓜的产量、含糖量和水分利用率均有影响 ,砂田西瓜只有补灌量控制在 45mm左右 ,才能既提高产量和水分利用率 。

保护地渗灌管的埋深对土壤水盐动态及番茄生长的影响

研究了保护地渗灌管不同深度对土壤水盐动态、番茄生长发育及产量的影响。结果表明 ,渗灌管的埋深越浅 ,灌水周期越短 ,盐分积累越多 ;渗灌管埋深 3 0cm、管下铺设防渗槽时 ,有利于抑制盐分积累 ,番茄生长旺盛 ,株高、茎粗、果径等指标表现最佳 。

秸秆还田下灌溉方式对水稻产量及水分利用率的影响

为探究秸秆还田结合节水灌溉技术的应用效果,本试验通过在秸秆全量还田条件下,设置不同灌溉方式,研究其对水稻生长发育、产量及其构成因素、水分利用效率等的影响,结果表明,在水稻生长发育上,秸秆还田下节水灌溉能够在一定程度上提高水稻中前期分蘖数,降低成熟期水稻植株株高,随着灌水量的减少,分蘖成穗率逐渐降低;在水稻生长发育的中前期,适当减少水分供给有利于水稻叶片和茎鞘干物质的积累,叶片干物质输出率与转换率以控灌I处理最大,分别达到14.19%和4.15%,茎鞘干物质输出率和转换率间以歇灌溉处理最大,分别达28.69%和17.39%;在产量及其构成因子上,水稻产量依次为间歇灌溉>淹水灌溉>控灌I>控灌II;在水分利用效率上,灌溉水水分利用效率以控灌II最大,为3.55 kg·m-3,自然降水水分利用率以间歇灌溉最大,为1.10 kg·m-3,总水分利用率以控灌I最大,为0.75 kg·m-3。综上,在秸秆还田和保证产量的前提下,间歇灌溉和控灌I处理最佳。本研究为东北地区水稻秸秆还田下水分管理,提高水资源利用效率,促进水稻生产可持续发展提供了理论依据。

喷灌对冬小麦生长环境的调节及其对水分利用效率影响的研究

研究了在不同气候条件下喷灌对近地面空气温湿度和农田蒸发能力 (冠层顶部 2 0cm蒸发皿水面蒸发量 )的影响 ,在干热风天气条件下微量喷水对冠层温度和农田蒸发能力的影响 ,以及喷灌对冬小麦产量和水分利用效率的影响。试验结果表明 ,如果 4～ 5月份降水量较少、空气相对湿度较低 ,则喷灌会明显降低近地面空气日最高温度和日平均温度 ,增加日平均相对湿度特别是最低相对湿度。喷灌条件下农田蒸发能力明显低于地面灌溉。微量喷水明显降低冠层温度和降低农田蒸发能力。农田蒸发能力变化与喷水量和日最高温度成正比 ,与日最低相对湿度和风速成反比。喷灌条件下冬小麦的产量和水分利用效率明显高于地面灌溉。

喷灌条件下冬小麦生理特征及生态环境特点的试验研究

通过定点定位试验 ,比较了喷灌与常规畦灌条件下农田生态环境、冬小麦光合速率和蒸腾速率的日变化特征以及不同水平的水分利用效率。结果表明 ,喷灌可以明显改善农田生态环境 ,减少作物蒸腾驱动势 ,使气孔阻力增大 ,最终导致蒸腾速率降低 ;在土壤水分相近条件下 ,喷灌条件下叶片的光合速率明显高于畦灌的光合速率 ,而蒸腾速率明显低于畦灌的蒸腾速率 ;喷灌小麦叶片水平水分利用效率和产量水平的水分利用效率均高于畦灌 ,表明在华北平原喷灌是改善农田生态环境和发展节水农业的一个有利措施。

不同灌水参数组合时田面坡度对灌水质量的影响研究

田面坡度是影响畦灌灌水质量的重要因素,研究田面坡度对灌水性能的影响时,要结合灌水定额、平整精度、田面糙率和单宽流量等参数进行分析。通过对常规平地技术条件下多组合灌溉参数模拟分析得出:不同灌水定额、平整精度、田面糙率和单宽流量组合对应不同的最佳田面坡度,当灌水定额为60.00 mm,平整精度为4.25 cm,田面糙率为0.12,单宽流量分别为4、3 L/(s.m)和2 L/(s.m)时,反向模拟出最佳的田面坡度分别为1.6‰、1.8‰和2.2‰;并通过研究田面坡度对水流推进和消退过程的影响得出:田面坡度为2.0‰的水流推进和消退过程曲线明显比1.6‰和1.2‰的曲线平滑,说明在较小的单宽流量条件下,相对较大的田面坡度可使田面水流运动更加稳定,有利于改善灌水质量。

施氮对南疆荒漠绿洲滴灌棉田产量及棉纤维品质的影响

设计0、150、300、450、600、750 kg/hm2 6种纯氮投入量，600～750 kg/hm2为农民习惯投入量，研究超量施氮对棉花产量、品质及氮肥利用效率的影响。结果表明：农民习惯施氮量是经济施氮量的1.53～1.91倍，产量仅为78.00%～78.60%，氮肥的利用效率显著降低，减少20％～60％的氮肥用量是可行的。增施氮肥对单株结铃数影响显著，对铃质量、衣分等无显著影响，过低、过高的氮肥均不利于高产结构的形成。随施氮量的增加纤维长度、麦克隆值，呈开口向下的抛物线状，超量施氮显著降低纤维的强力。在纤维品质的空间变异性方面，长度、强力受氮肥的影响较大，麦克隆值、短绒指数、伸长率受影响相对较小。可见，300～450 kg/hm2的氮肥投入增产效果最显著，氮肥利用效率最高，纤维品质较优。

适宜施氮量提高温室砂田滴灌甜瓜产量品质及水氮利用率

为解决设施砂田甜瓜生产中的水肥瓶颈问题,该文通过大田试验,研究西北旱区设施砂田甜瓜传统水肥管理与滴灌施肥处理对不同生育时期甜瓜生长、产量、品质及水氮利用率的影响,从而确定甜瓜高效的灌溉方式及适宜的氮肥用量。试验设置了2个对照处理：大水漫灌不施氮肥（CK0）和大水漫灌传统施氮（CK）,并在灌水量减少40%的滴灌条件下设置了4个氮肥水平：不施氮（T1）、传统施氮量N 180 kg/hm2（T2）、减氮40%即N 108 kg/hm2（T3）、增氮40%即N 252 kg/hm2（T4）,共6个处理。结果表明：滴灌施肥处理较对照在甜瓜生长后期光合、植株干物质及氮素积累量等生理、生长指标均显著提高,甜瓜增产7.40%～14.35%,水、氮利用率分别提高28.81%～40.65%和22.78%～77.22%,果实品质中可溶性固形物及Vc含量也显著提高,硝酸盐含量显著降低,且滴灌可减少砂层含土量,从而延长砂田的使用年限。相同滴灌条件不同氮水平处理间,甜瓜植株干物质及氮素积累量随施氮量的增加而增加,而光合指标、产量、品质及水氮利用率则表现出先增加后降低的趋势,其中以T2和T3处理的甜瓜产量、品质和水氮利用率最高。综合分析表明,滴灌施肥是西北旱区设施砂田甜瓜栽培优质高产、高效和节水节肥的水肥管理模式,适宜的氮肥施用量为108～180 kg/hm2。

喷灌对农田小气候的影响研究

试验研究喷灌对农田小气候的影响结果表明 ,喷灌影响灌水当时冠层附近空气温度与湿度 ,且整个喷灌周期均对其产生影响。喷灌作物冠层上方出现的逆温时间较长 ,冠层附近温度较低且湿度较大。喷灌地表温度日变幅明显小于地面灌处理且随土层深度的增加 2种灌水处理地温日变幅迅速减小。喷灌和地面灌处理冬小麦全生育期总耗水量分别为 43 6.5mm和 459.4mm ,产量分别为 643 0kg/hm2 和 4455kg/hm2 ,水分利用效率分别为1.47kg/m3 和 0 .97kg/m3 ,喷灌比地面灌水分利用效率高 52 %。

喷灌农田小气候变化及其对作物生长影响的研究进展

喷灌对田间小气候和作物生长的研究综述与分析认为 :喷灌水滴蒸发和冠层截留蒸发是喷灌能够调节农田小气候的主要原因。喷灌水滴蒸发量一般小于 2 5 % ,冠层截留一般在 1%～ 4 2 %的范围内。喷灌农田冠层温度降低、湿度增大。在寒冷季节 ,通过喷灌可改善作物冠层的热量状况。喷灌后田间作物光合速率提高 ,蒸腾强度降低。最终表现为喷灌条件下作物耗水量较小 ,产量和水分利用效率较高。作物冠层的截留水量是喷灌能够长时间调节田间小气候的主要原因之一。进一步研究冠层截留水量在冠层内的分配、存储 ,冠层内的水汽交换、温湿度变化、冠层内水分的消散过程、喷灌后温湿度的空间分布等 。

井灌区节水灌溉效率与潜力分析——以内蒙古通辽市为例

在对内蒙古通辽市井灌区水资源利用现状和农业灌区用水现状进行实际调查与分析的基础上,按不同灌溉方式、土壤类型、分布位置和灌溉管理水平选择典型样点灌区,分别用田间实测法和水量平衡法科学地测算不同灌溉方式下的样点灌区、灌区和地区的灌溉水利用效率,并分析评估样点灌区、灌区和地区三个尺度的节水效果与潜力。测算得出通辽市所辖的奈曼旗、科尔沁左翼中旗、科尔沁区、开鲁县、库伦旗、科尔沁左翼后旗、扎鲁特旗和霍林郭勒市灌溉水利用系数分别为0.799、0.832、0.813、0.803、0.823、0.806、0.802和0.810。。现状年通辽市地下水灌溉总面积为64万hm^2,其中节水灌溉面积为30万hm^2,还有34万hm^2农田使用传统的灌溉形式。假定未来34万hm^2待改造农田全部发展为低压管灌时,通辽市64万hm^2灌溉面积可节约水量3 860万m^3;全部发展为喷灌时,可节约水量8 298万m^3;全部发展为膜下滴灌时,可节约水量10 904万m^3。各灌区灌溉水利用效率的高低主要取决于不同灌溉方式的面积占总灌溉面积的比例,采用高效节水灌溉可整体提升灌区灌溉效率。