Guan'gai paishui xuebao (Sep 2023)
Evapotranspiration Variation and Attribution Analysis of Maize Field under Typical Border Irrigation in Shiyang River Basin
Abstract
【Objective】 Field evapotranspiration is the main consumption item of agricultural water. It is of great significance to clarify the evapotranspiration amount of crops during the growth period. 【Method】 Based on eddy correlation system, the evapotranspiration of maize field under typical border irrigation in northwest China was continuously observed at Shiyanghe Experimental Station, China Agricultural University from 2015 to 2018. Based on the partial correlation analysis and structural equation model, the relationship between evapotranspiration and meteorological factors during the growth period was analyzed. 【Result】 During the experiment period, the average evapotranspiration during the growing period of maize field under border irrigation was 524.3 mm, and the average daily evapotranspiration was 3.5 mm/d. The daily evapotranspiration showed a single-peak trend of rising to decreasing and reached its peak in July. Based on the analysis of the relationship between evapotranspiration and environmental factors during the experiment period, it can be seen that the correlation between net radiation and evapotranspiration is the largest, and the top three factors influencing the degree of environmental factors are net radiation, temperature and saturated vapor pressure difference. Based on the structural equation model (SEM), it was found that there was a positive correlation between leaf area index (LAI) as an intermediate variable and evapotranspiration, and net radiation, temperature and saturated vapor pressure difference were still the three environmental factors that had the greatest influence on evapotranspiration. 【Conclusion】 This study can provide a scientific basis for studying typical field evapotranspiration in Northwest China and understanding the impact of environmental change on crop evapotranspiration.
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