灌水延续时间对作物产量及灌溉制度影响的研究

Research on Effect of Irrigation Duration on Crop Yield and Irrigation Scheduling

灌水延续时间是确定灌水率进而影响渠道断面大小等工程规模的重要依据。利用天津农学院灌溉试验基地2008年和2009年两个年度冬小麦试验资料率定和检验作物水模型,以作物水模型为依据,以灌溉效益最大为目标,建立了灌溉制度优化模型;采用模式法和外推法,分析确定了考虑灌水延续时间(10、15及20d)与不考虑灌水延续时间两种情况下的最优灌水时间和相应的作物产量。结果表明:不考虑灌水延续时间时,小麦的产量和效益随着灌水次数的增加而增加,并随着灌水次数的增加,相邻两次最优灌水时间间隔明显减小;考虑灌水延续时间确定的优化灌水时间,较常规不考虑灌水延续时间确定的最优灌水时间有明显的提前或延后现象;在有限供水条件下,考虑灌水延续时间进行灌溉制度优化可增加灌区总产量,因此,确定优化灌溉制度时应该考虑灌水延续时间。

Irrigation duration is the important basis to determine the irrigation modulus and then influence the engineering scale such as the canal section size etc .This paper use two annual experimental data in 2008 and 2009 of winter wheat in irrigation experiment base of Tianjin Agricultural University to calibrate and validate crop water model .Irrigation scheduling optimization model ,with the goal of maximizing the irrigation benefit ,was established based on the crop water model .The mode method and extrapolation meth‐od are adopted to analyze and determine the optimal irrigation time and corresponding crop yields under both cases of considering the irrigation duration （10 d ,15 d and 20 d） and not considering the irrigation duration .The results shown that ：regardless of the irriga‐tion duration ,the wheat yield and benefit increased with the increase of irrigation times ,and with the increase of irrigation times ,the interval between twice adjacent optimal irrigation time obviously decreased .The determinate optimal irrigation time under considering irrigation duration ,compared with conventionally optimal irrigation time regardless of the irrigation duration ,which clearly appears in advance or delays .Under limited water supply ,optimizing irrigation scheduling with considering irrigation duration can increase the total yields of irrigated area . Therefore , irrigation duration should be considered in determining the optimized irrigation scheduling .