为确定滴灌条件下温室黄瓜的适宜灌水方案,该文基于20 cm标准蒸发皿的累计水面蒸发量设计不同灌水处理,研究了滴灌条件下不同灌水处理(充分灌水T1,轻度水分亏缺T2,中度水分亏缺T3)对不同种植季节温室黄瓜生理特性、耗水量(Evapotranspir...为确定滴灌条件下温室黄瓜的适宜灌水方案,该文基于20 cm标准蒸发皿的累计水面蒸发量设计不同灌水处理,研究了滴灌条件下不同灌水处理(充分灌水T1,轻度水分亏缺T2,中度水分亏缺T3)对不同种植季节温室黄瓜生理特性、耗水量(Evapotranspiration,ET_c)、产量及水分利用效率(Water Use Efficiency,WUE)的影响,且于2017年8-12月(秋冬季)和2018年3-7月(春夏季)分别对不同灌水处理下土壤水分状况、作物生理指标、耗水量、产量和WUE等指标进行了系统的田间试验观测及分析。研究结果表明,随着灌水量的减小,温室黄瓜产量和WUE均呈降低趋势,不同程度的水分亏缺对黄瓜不同生育期ET_c有一定的抑制作用,在黄瓜生长任一阶段发生水分亏缺均会降低黄瓜植株的茎流速率、光合速率及气孔导度,进而可能影响黄瓜干物质的运转与积累,其中在作物生长中期,温室黄瓜茎流速率及产量对水分亏缺响应最为显著。黄瓜平均单果质量、果茎、果长和单株坐果数均随灌水量的降低而减小,黄瓜果实畸形比例随不同生长阶段水分亏缺的增大而增大。不同种植季节温室黄瓜T1处理的产量分别高出T2和T3处理的22.0%和51.2%(春夏季)、54.2%和73.9%(秋冬季);温室黄瓜T1处理的ET_c分别高出T2和T3处理的17.4%和34.9%(春夏季)、24.0%和48.0%(秋冬季);T1处理的WUE分别高出T2和T3处理的5.5%和25%(春夏季)、39.7%和50.0%(秋冬季)。综合研究结果,黄瓜发育期适宜灌溉水量为累计水面蒸发量的0.8倍,生长中、后期为累计水面蒸发量的1.2倍。研究结果对实现农业水分高效利用及促进设施作物优质、高产具有重要参考价值。展开更多
Water is the scarcest resource and the importance of the judicious use of water in the agricultural sector for sustaining agricultural growth and the retardation of environmental degradation needs no further elaborati...Water is the scarcest resource and the importance of the judicious use of water in the agricultural sector for sustaining agricultural growth and the retardation of environmental degradation needs no further elaboration.The successes of using sprinkler irrigation to develop new lands,point the way forward to a much greater role for the development of future land reclamation projects.Water use efficiency through a proper improvement of water management techniques and other production factors are essential to boost on-farm productivity.Various factors affecting uniformity and water use efficiency in sprinkler irrigation have been outlined in this research,highlighting possible ways to improve such essential parameters in crop production.The study emphasizes on an irrigation system that works adequately in applying water to stay within the root zone,making the water always available in sufficient quantities to meet the crop water needs.It suggests practical ways of managing irrigation systems within tolerable limits not neglecting the effects of wind which is a major contributing factor to non uniformity in sprinkler irrigation.展开更多
Accurate estimation of evapotranspiration is important in efficient water management for improving water use efficiency.In order to obtain evapotranspiration and evaporation beneath the canopy using the Food and Agric...Accurate estimation of evapotranspiration is important in efficient water management for improving water use efficiency.In order to obtain evapotranspiration and evaporation beneath the canopy using the Food and Agriculture Organization(FAO)method,pan evaporation was used instead of reference evapotranspiration calculated by the Penman-Monteith equation with detailed meteorological data.The total crop coefficient and soil evaporation coefficient were determined using actual measured daytime evapotranspiration and evaporation by the Bowen ratio energy balance and lysimeter,respectively,in a rice paddy field in Japan.The average evapotranspiration was 5.3 mm/d,4.4 mm/d,7.4 mm/d and 6.3 mm/d and crop coefficient was 0.79,1.18,1.01 and 0.86 for the initial stage,development stage,middle-season stage and late-season stage,respectively.The evaporation was low and almost constant with an average value around 0.77 mm/d when the leaf area index(LAI)reached 3.The proposed average crop coefficients for different growing stages were applied to estimate daytime evapotranspiration and found suitable.A simple soil water evaporation coefficient model was developed using leaf area index for practical use and it was found that it could accurately estimate evaporation.展开更多
The objective of this study was to calibrate and test AquaCrop for tomato(Lycopersicon esculentum)grown under deficit and full irrigation.Two field experiments were carried out in the tropical humid coastal savanna zo...The objective of this study was to calibrate and test AquaCrop for tomato(Lycopersicon esculentum)grown under deficit and full irrigation.Two field experiments were carried out in the tropical humid coastal savanna zone in Mfantseman district of the Central Region of Ghana.Data from the first experiment were used to calibrate the model while data obtained from the second experiment were used to validate the model.The calibrated AquaCrop model concentrated on its performance to predict crop yield and seasonal crop water requirement(ETc).Four treatments were investigated:T1(no irrigation after plant establishment),T2(50%ETc restoration),T3(100%ETc restoration up to beginning of flowering,then 50%ETc restoration)and T4(100%ETc restoration).The results revealed that AquaCrop was able to simulate the yield of tomato for T2-T4 with the exception of Treatment T1 which was simulated with the highest deviation of 45.1%.On the other hand,the model was able to simulate the seasonal water requirements to an appreciable degree in both experiments.It must be pointed out that the calibration of AquaCrop suffered from a lack of data on the progress of crop canopy cover which is a very important parameter used in developing the model.展开更多
文摘为确定滴灌条件下温室黄瓜的适宜灌水方案,该文基于20 cm标准蒸发皿的累计水面蒸发量设计不同灌水处理,研究了滴灌条件下不同灌水处理(充分灌水T1,轻度水分亏缺T2,中度水分亏缺T3)对不同种植季节温室黄瓜生理特性、耗水量(Evapotranspiration,ET_c)、产量及水分利用效率(Water Use Efficiency,WUE)的影响,且于2017年8-12月(秋冬季)和2018年3-7月(春夏季)分别对不同灌水处理下土壤水分状况、作物生理指标、耗水量、产量和WUE等指标进行了系统的田间试验观测及分析。研究结果表明,随着灌水量的减小,温室黄瓜产量和WUE均呈降低趋势,不同程度的水分亏缺对黄瓜不同生育期ET_c有一定的抑制作用,在黄瓜生长任一阶段发生水分亏缺均会降低黄瓜植株的茎流速率、光合速率及气孔导度,进而可能影响黄瓜干物质的运转与积累,其中在作物生长中期,温室黄瓜茎流速率及产量对水分亏缺响应最为显著。黄瓜平均单果质量、果茎、果长和单株坐果数均随灌水量的降低而减小,黄瓜果实畸形比例随不同生长阶段水分亏缺的增大而增大。不同种植季节温室黄瓜T1处理的产量分别高出T2和T3处理的22.0%和51.2%(春夏季)、54.2%和73.9%(秋冬季);温室黄瓜T1处理的ET_c分别高出T2和T3处理的17.4%和34.9%(春夏季)、24.0%和48.0%(秋冬季);T1处理的WUE分别高出T2和T3处理的5.5%和25%(春夏季)、39.7%和50.0%(秋冬季)。综合研究结果,黄瓜发育期适宜灌溉水量为累计水面蒸发量的0.8倍,生长中、后期为累计水面蒸发量的1.2倍。研究结果对实现农业水分高效利用及促进设施作物优质、高产具有重要参考价值。
基金the Natural Science Foundation of China(51509107,51609103)Natural Science Foundation of Jiangsu province(BK20140546,BK20150509)+3 种基金The authors are greatly indebted to the National Key Research and Development Program of China(No.2016YFC0400202)the Project of New Agricultural Machinery in Jiangsu Province(No.NJ2016-11)the Postdoctoral Science Foundation Special Support of China(No.2016T90428)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Water is the scarcest resource and the importance of the judicious use of water in the agricultural sector for sustaining agricultural growth and the retardation of environmental degradation needs no further elaboration.The successes of using sprinkler irrigation to develop new lands,point the way forward to a much greater role for the development of future land reclamation projects.Water use efficiency through a proper improvement of water management techniques and other production factors are essential to boost on-farm productivity.Various factors affecting uniformity and water use efficiency in sprinkler irrigation have been outlined in this research,highlighting possible ways to improve such essential parameters in crop production.The study emphasizes on an irrigation system that works adequately in applying water to stay within the root zone,making the water always available in sufficient quantities to meet the crop water needs.It suggests practical ways of managing irrigation systems within tolerable limits not neglecting the effects of wind which is a major contributing factor to non uniformity in sprinkler irrigation.
基金supported by the Natural Science Foundation of China(51509107,51609103)the Key Laboratory of Agricultural Water Resources,the Chinese Academy of Sciences(No.KFKT201605)+3 种基金Natural Science Foundation of Jiangsu province(BK20140546,BK20150509)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(2015,No.311)Jiangsu University Senior Professional Scientific Research Fund Project(14JDG015,14JDG017,12JDG097)Jiangsu Universities Engineering Discipline Construction Project(1033000001).
文摘Accurate estimation of evapotranspiration is important in efficient water management for improving water use efficiency.In order to obtain evapotranspiration and evaporation beneath the canopy using the Food and Agriculture Organization(FAO)method,pan evaporation was used instead of reference evapotranspiration calculated by the Penman-Monteith equation with detailed meteorological data.The total crop coefficient and soil evaporation coefficient were determined using actual measured daytime evapotranspiration and evaporation by the Bowen ratio energy balance and lysimeter,respectively,in a rice paddy field in Japan.The average evapotranspiration was 5.3 mm/d,4.4 mm/d,7.4 mm/d and 6.3 mm/d and crop coefficient was 0.79,1.18,1.01 and 0.86 for the initial stage,development stage,middle-season stage and late-season stage,respectively.The evaporation was low and almost constant with an average value around 0.77 mm/d when the leaf area index(LAI)reached 3.The proposed average crop coefficients for different growing stages were applied to estimate daytime evapotranspiration and found suitable.A simple soil water evaporation coefficient model was developed using leaf area index for practical use and it was found that it could accurately estimate evaporation.
基金the National Natural Science Foundation of China(number 51309117)the Program for National Hi-Tech Research and Development of China(863 Program,number 2011AA100506)+4 种基金This study has also been financially supported by the Natural Science Foundation of China(51509107)Natural Science Foundation of Jiangsu province(BK20140546)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(2015,No.311)the Agricultural machinery of Sanxin project in Jiangsu province(NJ2014-10)Jiangsu University Senior Professional Scientific Research Fund Project(14JDG015,14JDG017).
文摘The objective of this study was to calibrate and test AquaCrop for tomato(Lycopersicon esculentum)grown under deficit and full irrigation.Two field experiments were carried out in the tropical humid coastal savanna zone in Mfantseman district of the Central Region of Ghana.Data from the first experiment were used to calibrate the model while data obtained from the second experiment were used to validate the model.The calibrated AquaCrop model concentrated on its performance to predict crop yield and seasonal crop water requirement(ETc).Four treatments were investigated:T1(no irrigation after plant establishment),T2(50%ETc restoration),T3(100%ETc restoration up to beginning of flowering,then 50%ETc restoration)and T4(100%ETc restoration).The results revealed that AquaCrop was able to simulate the yield of tomato for T2-T4 with the exception of Treatment T1 which was simulated with the highest deviation of 45.1%.On the other hand,the model was able to simulate the seasonal water requirements to an appreciable degree in both experiments.It must be pointed out that the calibration of AquaCrop suffered from a lack of data on the progress of crop canopy cover which is a very important parameter used in developing the model.
