东北春玉米单株茎流变化规律及其农田尺度提升方法  

Variations of sap flow rate and its farmland scale improving method for spring maize in northeast China

作　　者：黄茜 杨伟才 毛晓敏[1,2] Huang Xi;Yang Weicai;Mao Xiaomin(College of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China;Wuwei Experimental Station for Efficient Water Use in Agriculture,Ministry of Agriculture and Rural Affairs,Wuwei 733000,China)

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]农业农村部作物高效用水武威科学观测实验站,武威733000

出　　处：《农业工程学报》2020年第16期94-102,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2016YF040106-3);国家自然科学基金项目(51679234)。

摘　　要：为揭示春玉米单株茎流速率规律,明确单株茎流提升至群体蒸腾的尺度转换因子,2017和2018年连续在东北典型黑土区开展了春玉米田间试验,对春玉米灌浆期内茎流速率、气象数据、棵间蒸发及土壤剖面含水率进行观测和分析。结果表明:春玉米茎流速率有明显的昼夜变化规律,降雨对玉米茎流有较强的抑制作用,降雨后茎流速率明显升高;在晴、阴、雨天气情况下玉米白天茎流差异较大,且在阴雨天气情况下,茎流曲线呈多峰曲线,峰值较低。玉米茎流的变化是各种环境因素综合作用的结果,其中茎流速率与空气温度、光合有效辐射、相对湿度间相关系数的绝对值皆在0.8以上,表明他们是影响东北黑土区茎流速率的主要环境因素。以茎粗、茎干截面面积、叶面积为尺度转换因子将单株茎流尺度提升得到春玉米农田尺度群体蒸腾量,将2 a灌浆期春玉米群体蒸腾量与棵间蒸发之和,与水量平衡法计算得到的蒸发蒸腾量进行比较,误差均在20%以内。3种尺度提升方法和水量平衡法得到2 a春玉米灌浆期内日均蒸发蒸腾量分别在4.22~4.78、3.91~4.56 mm/d范围内。其中以叶面积为尺度转换因子计算的蒸发蒸腾量与水量平衡法的结果最为接近,相对误差在5%左右,表明东北高寒黑土区春玉米农田适合采用叶面积作为单株向农田尺度提升的转换因子。Maize is one of the main food crop in the northeast China.It is of great significance to understand the sap flow rate variation and its environmental impact factors for optimizing the structure of maize production and achieving high water use efficiency in the northeast China.In order to reveal the daily variation of sap flow rate and its environmental impact factors,to clarify the scaling conversion factors for upscaling individual plant sap flow estimation to the farmland level,and to investigate the characteristics of evapotranspiration(ET)during the filling stage,field experiments were conducted in two consecutive years(2017 and 2018)in the northeast China.The sap flow rates,crop growth indices,meteorological data,soil evaporation and soil water content of the root zone in black soil were determined.The results showed that there was an obvious day-night fluctuation of spring maize sap flow rate,and the average peak values of sap flow rate in the two years were 58.72 and 48.26 g/h,respectively.Rainfall events had a strong inhibitory effect on the sap flow of spring maize,and the sap flow rate increased significantly after rainfall,even higher than that before rainfall.The sap flow rate was quite different among the sunny,cloudy and rainy days.The sap flow rate revealed a multi-peak curve in the cloudy and rainy days.The maize sap flow rate was the highest in the the sunny day,followed by cloudy and rainy days,with the average values of 16.14,8.28,3.13 g/h respectively in 2018.The variation of sap flow rate could be regarded as the result induced by the comprehensive effects of various environmental factors.According to the correlation analysis,the sap flow rate had a significant positive correlation with air temperature,wind speed,water vapor pressure and photosynthetic active radiation,and a significant negative correlation with relative humidity and soil temperature.The absolute values of the correlation coefficients between the sap flow rate and air temperature,photosynthetic active radiation,and relative h

关 键 词：蒸发蒸腾量 蒸腾 蒸发 春玉米 茎流速率 尺度提升 支持向量机回归 

分 类 号：P426.2[天文地球—大气科学及气象学]