Responses of Crop Water Use Efficiency to Climate Change and Agronomic Measures in the Semiarid Area of Northern China.
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.
College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China; Key Ecology and Environment Experimental Station of Ministry of Agriculture for Field Scientific Observation in Hohhot, Wuchuan, Hohhot, 011705, China.
Jingting
J
Zhang
Department of Plant & Soil Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40506, United States of America; International Center for Climate and Global Change Research, Auburn University, Auburn, AL, 36849, United States of America.
Wei
W
Ren
College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China; Key Ecology and Environment Experimental Station of Ministry of Agriculture for Field Scientific Observation in Hohhot, Wuchuan, Hohhot, 011705, China.
Pingli
P
An
College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China; Key Ecology and Environment Experimental Station of Ministry of Agriculture for Field Scientific Observation in Hohhot, Wuchuan, Hohhot, 011705, China.
Zhihua
Z
Pan
College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China; Key Ecology and Environment Experimental Station of Ministry of Agriculture for Field Scientific Observation in Hohhot, Wuchuan, Hohhot, 011705, China.
Liwei
L
Wang
College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China; Key Ecology and Environment Experimental Station of Ministry of Agriculture for Field Scientific Observation in Hohhot, Wuchuan, Hohhot, 011705, China.
Zhiqiang
Z
Dong
College of Resources and Environmental Science, China Agricultural University, Beijing, 100193, China.
Di
D
He
International Center for Climate and Global Change Research, Auburn University, Auburn, AL, 36849, United States of America.
Jia
J
Yang
International Center for Climate and Global Change Research, Auburn University, Auburn, AL, 36849, United States of America.
Shufen
S
Pan
International Center for Climate and Global Change Research, Auburn University, Auburn, AL, 36849, United States of America.
Hanqin
H
Tian
D002681:China; D002980:Climate; D057231:Climate Change; D018556:Crops, Agricultural; D055864:Droughts; D005308:Fertilizers; D014867:Water
D005308:Fertilizers; D014867:Water