It has long been concerned how crop water use efficiency (WUE) responds to climate change. Most of existing researches have emphasized the impact of single climate factor but have paid less attention to the effect of developed agronomic measures on crop WUE. Based on the long-term field observations/experiments data, we investigated the changing responses of crop WUE to climate variables (temperature and precipitation) and agronomic practices (fertilization and cropping patterns) in the semi-arid area of northern China (SAC) during two periods, 1983-1999 and 2000-2010 (drier and warmer). Our results suggest that crop WUE was an intrinsical system sensitive to climate change and agronomic measures. Crops tend to reach the maximum WUE (WUEmax) in warm-dry environment while reach the stable minimum WUE (WUEmin) in warm-wet environment, with a difference between WUEmax and WUEmin ranging from 29.0%-55.5%. Changes in temperature and precipitation in the past three decades jointly enhanced crop WUE by 8.1%-30.6%. Elevated fertilizer and rotation cropping would increase crop WUE by 5.6-11.0% and 19.5-92.9%, respectively. These results indicate crop has the resilience by adjusting WUE, which is not only able to respond to subsequent periods of favorable water balance but also to tolerate the drought stress, and reasonable agronomic practices could enhance this resilience. However, this capacity would break down under impact of climate changes and unconscionable agronomic practices (e.g. excessive N/P/K fertilizer or traditional continuous cropping). Based on the findings in this study, a conceptual crop WUE model is constructed to indicate the threshold of crop resilience, which could help the farmer develop appropriate strategies in adapting the adverse impacts of climate warming.
Digital Object Identifier (DOI)
The National Natural Science Foundation of China (41271110, 41371232), the National Basic Research Program of China (2012CB956204) and the National Non-profit Research Foundation for Meteorology (GYHY201506016). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Zhang, Jingting; Ren, Wei; An, Pingli; Pan, Zhihua; Wang, Liwei; Dong, Zhiqiang; He, Di; Yang, Jia; Pan, Shufen; and Tian, Hanqin, "Responses of Crop Water Use Efficiency to Climate Change and Agronomic Measures in the Semiarid Area of Northern China" (2015). Plant and Soil Sciences Faculty Publications. 59.
S1 Dataset. Raw data of climate and fertilizer change during 1980–2010.
journal.pone.0137409.s002.XLSX (10 kB)
S2 Dataset. Raw data of crop WUE change during 1983–2010.
journal.pone.0137409.s003.XLSX (12 kB)
S3 Dataset. Raw data of crop ET and yield in wet and dry years.
journal.pone.0137409.s004.XLSX (14 kB)
S4 Dataset. Raw data of climate, fertilizer and WUE in Wuchuan and Guyuan.
journal.pone.0137409.s005.XLSX (19 kB)
S5 Dataset. Raw data of panel model.
journal.pone.0137409.s006.XLSX (10 kB)
S6 Dataset. Raw data of cropping pattern experiment during 2008–2010.