喷灌均匀性和灌水量对冬小麦冠层下水量分配的影响  

Effects of sprinkler uniformity and irrigation volume on the water distribution below the canopy of winter wheat

作　　者：李红[1] 郭鑫 陈瑞 王剑 Li Hong;Guo Xin;Chen Rui;Wang Jian(Research Center of Fluid Machinery Engineering and Technology,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学流体机械工程技术研究中心,镇江212013

出　　处：《农业工程学报》2021年第24期102-111,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金重点项目(51939005);江苏省农业科技自主创新资金项目(CX(21)3078)。

摘　　要：为研究冬小麦冠层对喷灌水量的再分配规律,探讨不同灌水量下喷灌均匀性对土壤含水率空间分布、冬小麦生长状况及产量的影响,该研究于2020—2021年在常州市金坛区开展了冬小麦田间喷灌试验。该试验依据作物需水量设置3个灌水量(充分灌溉、2/3需水量、1/3需水量)处理和2个喷灌均匀性(高:75%、低:55%)处理,通过冠层上、下雨量筒和自制的茎流收集器测量喷灌水量分布,并对喷灌后的土壤含水率(Soil Water Content,SWC)、冬小麦生长状况及产量的空间分布进行了监测。结果表明,冠层上喷灌均匀性比冠层下高约1.5%。喷灌水经冬小麦冠层再分配后所形成的棵间穿透流量、茎秆流量以及冠下喷灌损失分别占冠层上部水量的56.0%~73.9%、25.0%~37.0%和2.5%~12.7%。冠下穿透流率和茎秆流率与冬小麦的冠层特征(叶面积指数、株高)极显著相关(P<0.01),而受喷灌均匀性和灌水量的影响较小。茎秆流率变异系数高于穿透流率变异系数。喷灌后24 h,0~20 cm深度土壤水分的变化与冬小麦产量及产量变异系数显著相关(P<0.05)。低喷灌均匀性会导致区域性缺水(SWC<65%田间持水量),引发小范围减产,产量变异系数增大,减少灌水量则会加剧这一现象,冬小麦显著减产,灌水量对产量的影响占主导作用。研究结果可为冬小麦的喷灌设计提供理论依据。Sprinkler uniformity has posed a great challenge to the crop yield and water use efficiency in an irrigation system. A sprinkler is required to evenly deliver the water over the canopy and ground during and after the irrigation, where the crop canopy covers the surface. This study aims to explore the effect of sprinkler uniformity on the spatial distribution of soil water content, growth condition, and crop yield below different irrigation systems. The redistribution of sprinkler water was also considered below the crop canopy. A field test was conducted at the sprinkler irrigation experimental field of the Jiangsu University in Jintan District, Changzhou City, Jiangsu Province, in China(31.45′N, 119.17′E). Three treatments of irrigation(full irrigation, 2/3, and 1/3 water demand) and two levels of sprinkler uniformity(high: 75%, low: 55%) were set, according to the water demand for the winter wheat. Specifically, the sprinkler uniformity was obtained to adjust the sprinkler operating pressure(150-300 kPa) or the number of sprinklers simultaneously within each treatment(2-4). The irrigation volume was also evaluated, as the irrigation time changed. The distribution of sprinkler water was measured by the rain cans above and below the canopy, and a homemade stem-flow collector. Some parameters were also monitored, including the spatial distribution of soil water content, the growth and yield of winter wheat after sprinkler irrigation. The results showed that the interplant throughfall, stemflow, and below-canopy sprinkler losses(resulting from the redistribution of sprinkler water through the canopy) were ranged from 56.0%-73.9%, 25.0%-37.0%, and 2.5%-12.7% of the water above the canopy, respectively. There was a linear correlation(P<0.01) between the amount of water above and below the canopy in three sprinkler irrigations during the growing period. There was no significant change in the total amount of water below the canopy, due to the penetration and stalk flow in the canopy during the pulling-maturity peri

关 键 词：灌溉 作物 冠层 冬小麦 灌水量 土壤含水率 

分 类 号：S275.5[农业科学—农业水土工程]