Aim of study: To determine seasonal variations in evapotranspiration (ET) and its components; and ascertain the key factors controlling ET and its components in a rainfed spring maize field under plastic film. Area of study: Shouyang County in Shanxi Province on the eastern Loess Plateau, China Material and methods: Eddy covariance system combined with micro-lysimeters and meteorological observing instruments were used in the field. The manual method was used to measure the green leaf area index (GLAI) during the growing season. Main results: In 2015 and 2016, the growing season ET accounted for 80% and 79% of annual ET, respectively. Soil evaporation (E) accounted for 36% and 33% of the growing season ET in 2015 and 2016, respectively. The daily crop coefficient increased with increasing GLAI until a threshold of ~3 m2 m−2 in the canopy-increasing stage, and decreased linearly with decreasing GLAI in the canopy-decreasing stage. At equivalent GLAI, daily basal crop coefficient and soil water evaporation coefficient were generally higher in the canopy-increasing and-decreasing stages, respectively. During the growing season, the most important factor controlling daily ET, T, and E was net radiation (Rn), followed by GLAI for daily ET and T, and soil water content at 10-cm depth for daily E; during the non-growing season, daily ET was mainly controlled by Rn. Research highlights: The daily crop coefficient and its components reacted differently to GLAI in the canopy-increasing and-decreasing stages.
CITATION STYLE
Gao, X., Gu, F. X., Gong, D. Z., Hao, W. P., Chu, J. M., & Li, H. R. (2020). Evapotranspiration and its components over a rainfed spring maize cropland under plastic film on the Loess plateau, China. Spanish Journal of Agricultural Research, 18(4), 1–11. https://doi.org/10.5424/sjar/2020184-16370
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