Characteristics and cause analysis of flue-cured tobacco's water requirements during growth periods in low latitude plateau area, China

This study aimed to identify the future changes in water requirements (ETc) of flue-cured tobacco by comparing estimated ETc values in the future with previous usage. This will provide a basis for estimating irrigation requirements, and help improve agricultural water use efficiency in the future. The Penman–Monteith equation and the single-crop efficient method were used to calculate the flue-cured tobacco ETc, net irrigation requirement (IR) and net irrigation requirement index (IDI) for the period 1956–2015, and the four IPCC AR5 emission scenarios were used to estimate ETc for two future periods (2046–2065 and 2081–2100) in the central Yunnan Province, China. The results showed that the IDI gradually decreased, along with the growth of flue-cured tobacco. The ETc, IR and IDI values increased with latitude in central Yunnan Province. Furthermore, the variations in the ETc over the whole growth period in the mid-21st century and late-21st century also tended to increase with latitude. In addition, based on the influence of climate variation on the ETc as assessed by a principal component analysis, precipitation was the main factor affecting flue-cured tobacco growth. This study contributes to the establishment of suitable irrigation systems for flue-cured tobacco at every growth stage in central Yunnan Province. doi: 10.2166/wcc.2018.296 s://iwaponline.com/jwcc/article-pdf/doi/10.2166/wcc.2018.296/501517/jwc2018296.pdf Na Fu Xiaoyu Song (corresponding author) Lu Xia Lanjun Li State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an 710048, China E-mail: songxy@xaut.edu.cn Xiaogang Liu Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming 650500, China