Open AccessEvapotranspiration and its components over a rainfed spring maize cropland under plastic film on the Loess Plateau, China
Author(s) -
Xiang Gao,
Fangyi Gu,
Daozhi Gong,
Weiping Hao,
Jianmin Chu,
Haoru Li
Publication year - 2021
Publication title -
spanish journal of agricultural research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.337
H-Index - 36
eISSN - 2171-9292
pISSN - 1695-971X
DOI - 10.5424/sjar/2020184-16370
Subject(s) - evapotranspiration , crop coefficient , canopy , environmental science , growing season , lysimeter , eddy covariance , agronomy , precipitation , soil water , water content , leaf area index , hydrology (agriculture) , ecosystem , soil science , geography , ecology , biology , geotechnical engineering , engineering , meteorology
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, ChinaMaterial 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.