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2015—2016年在中国农业科学院新乡综合试验基地,以华北地区典型日光温室滴灌番茄为研究对象,分析2种灌溉水平[参考20 cm标准蒸发皿的累积蒸发量(E_p),设置2种灌溉水平(高水:0.9Ep;低水:0.5Ep)]下番茄不同生育期土壤蒸发(E)、作物蒸腾(T)、蒸发蒸腾(ET)和土壤蒸发占蒸发蒸腾比值(E/ET)的变化,探讨水分亏缺对作物系数(K_c)的影响以及水分胁迫系数(K_s)在全生育期的动态变化.采用双作物系数法分别估算E、T和ET,并与实测结果进行对比分析.结果表明:2015和2016年全生育期高水处理的E分别比低水处理高21.5%和20.4%,占总蒸发蒸腾量的24.0%和25.0%,E/ET在生育初期最大、中期最小;高水处理的Kc值在生育初期、发育期、生育中期和生育后期分别为0.45、0.89、1.06和0.93,低水处理下分别为0.45、0.89、0.87和0.41;低水处理的Ks值在0.32~1.0,生育初期、发育期、生育中期和生育后期分别为0.98、0.93、0.78和0.39.双作物系数法可较精确地估算不同水分处理的ET,其平均绝对误差(MAE)为0.36~0.48 mm·d~(-1),均方根误差(RMSE)为0.44~0.65mm·d~(-1);该方法也可精确地估算E和T,其MAE分别为0.15~0.19和0.26~0.56 mm·d~(-1),RMSE分别为0.20~0.24和0.33~0.72 mm·d~(-1).
In 2015-2016, two irrigation levels were analyzed in the Xinxiang Integrated Test Base of Chinese Academy of Agricultural Sciences (CASS) in a typical solar greenhouse in North China [with reference to the cumulative evaporation (E_p) of a standard 20 cm evaporating dish) and two irrigation levels (High water: 0.9Ep; low water: 0.5Ep)]. The changes of soil evaporation (E), crop transpiration (T), evapotranspiration (ET) and soil evaporation to evapotranspiration (E / ET) (K_c) and the dynamic changes of water stress coefficient (K_s) during the whole growth period were studied.The E, T and ET were estimated by the double crop coefficient method and compared with the measured results.Results The results showed that the E of high-water treatment during the whole growth period of 2015 and 2016 were 21.5% and 20.4% higher than that of low-water treatment, accounting for 24.0% and 25.0% of the total evapotranspiration, respectively. E / ET was the highest in the early growth period and the lowest in the middle period. The Kc values of water treatment were 0.45, 0.89, 1.06 and 0.93 in the early growing stage, developing stage, middle growing stage and late growing stage, respectively, 0.45, 0.89, 0.87 and 0.41 in the low water treatment, 1.0, early growth period, developmental period, mid-growth period and late growth period were 0.98 0.93, 0.78 and 0.39.The double crop coefficient method can estimate the ET of different water treatments more accurately with the average absolute error (MAE) of 0.36 ~ 0.48 mm · d -1 and the root mean square error (RMSE) of 0.44 ~ 0.65mm · d ~ (-1). This method can also accurately estimate E and T with MAE of 0.15-0.19 and 0.26-0.56 mm · d -1, RMSE of 0.20-0.24 and 0.33 ~ 0.72 mm · d ~ (-1).