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BACKGROUND: Drought affects the characteristics of water use during crop production and so quantitatively evaluating the impacts is important. However, it remains unclear how crop water use responds to drought. To address this gap, water footprint (WF) and standardized precipitation evapotranspiration index (SPEI) were calculated by remote sensing approaches to assess the effects of drought on crop water use. Rainfed maize is the most important crop in Jilin Province, and its growth and water use are more susceptible to drought. The present study explored not only the impact of growing season drought on the maize WF values in Jilin Province, but also the response of WF values to drought at different time scales. RESULTS: Spatially, 72.94% of the WFblue pixels showed a non‐significant increase, and the WFgreen in 68% pixels decreased significantly, being mainly concentrated in the middle region. Furthermore, the pixels affected by monthly time scale drought were mainly in the middle region, whereas the pixels affected by annual time scale drought were mainly in the western region. CONCLUSION: Drought not only affected on the source and structure of agricultural water consumption, but also had different effects on WF values at different time scale. These effects had obvious spatial differences. The present study systematically explored the effects of drought on the WF values for rainfed maize in different climate regions and a consideration of these effects could provide valuable information on rainfed maize growth and the agricultural water use response to a changing climate. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Rice is a special crop, and its production differs from that of other crops because it requires a thin layer of water coverage for a long period. The calculation of the water footprint of rice production should differ from that of other crops owing to the rice growing process. This study improved the calculation of blue and grey water footprints of rice production and analyzed the variations in the water footprints for rice production under different rainfall years in Jilin Province. RESULTS: In the drought year, the green water footprint was the lowest and the blue water footprint was the highest among the three years, while in the humid year, the green water footprint was the highest and the blue water footprint was not the lowest. The areas with higher water footprints were found in the east and west regions of Jilin Province, while the areas with lower water footprints were found in the middle east and middle regions of Jilin Province. CONCLUSION: Blue water was the primary water resource for rice production, although more precipitation provided the highest green water in the humid year; also, the spatial distributions of water footprints were not the same under different rainfall years. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Field-scale changes in the water footprint during crop growth play an important role in formulating sustainable water utilisation strategies. This study aimed to explore field-scale variation in the water footprint of growing sunflowers in the western Jilin Province, China, during a 3-year field experiment. The goals of this study were to (1) determine the components of the 'blue' and 'green' water footprints for sunflowers sown with water, and (2) analyse variations in water footprints and soil water balance under different combinations of temperature and precipitation. Specific actions could be adopted to maintain sustainable agricultural water utilisation in the semi-arid region based on this study. RESULTS The green, blue, and grey water footprints accounted for 93.7-94.7%, 0.4-0.5%, and 4.9-5.8%, respectively, of the water footprint of growing sunflowers. The green water footprint for effective precipitation during the growing season accounted for 58.8% in a normal drought year but 48.2% in an extreme drought year. When the effective precipitation during the growing season could not meet the green water use, a moisture deficit arose. This increase in the moisture deficit can have a significant impact on soil water balance. CONCLUSION Green water was the primary water source for sunflower growth in the study area, where a scarcity of irrigation water during sunflower growth damaged the soil water balance, particularly in years with continuous drought. The combination of temperature and precipitation effected the growing environment, leading to differences in yield and water footprint. The field experiments in this area may benefit from further water footprint studies at the global, national and regional scale. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND Water footprint ( WF) methodology is essential for quantifying total water consumption of crop production and making efficient water management policies. This study calculated the green, blue, grey and total WFs of maize production in Northeast China from 1998 to 2012 and compared the values of the provinces. This study also analyzed the spatial variation and structure characteristics of the WFs at the prefecture level. RESULTS The annual average WF of maize production was 1029 m3 per ton, which was 51% green, 21% blue and 28% grey. The WF of maize production was highest in Liaoning Province, moderate in Heilongjiang Province and lowest in Jilin Province. The spatial differences of the WFs calculated for the 36 major maize production prefectures were significant in Northeast China. There was a moderate positive spatial autocorrelation among prefectures that had similar WFs. Local indicator of spatial autocorrelation index ( LISA) analysis identified prefectures with higher WFs in the southeast region of Liaoning Province and the southwest region of Heilongjiang Province and prefectures with lower WFs in the middle of Jilin Province. CONCLUSION Spatial differences in the WF of maize production were caused mainly by variations in climate conditions, soil quality, irrigation facilities and maize yield. The spatial distribution of WFs can help provide a scientific basis for optimizing maize production distribution and then formulate strategies to reduce the WF of maize production. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Rain-fed crops are a major crop type, and their water use is extremely vulnerable to climate change. Studying the water requirement characteristics of rain-fed crops in different growth stages and associated climatic driving factors is of great significance for sustainable crop production. The water footprint (WF) of crops can comprehensively reflect the type and quantity of water consumption during the crop growth period. Previous studies have focused on quantifying the crop WF throughout the growth period, and less attention has been given to quantifying the crop WF in different growth stages. This study quantified the WFs of rain-fed maize and associated climatic driving factors in five growth stages from 1996 to 2018 in Northeast China. The results show that (1) the WF of rain-fed maize in each growth stage showed distinct differences. The highest WF occurred in the tasseling-milky growth stage, whereas the lowest WF occurred in the sowing-emergence growth stage. (2) The variation trends of maize WF in different growth stages were heterogeneous across Northeast China. The declining trends were mainly distributed in the southwest, while increasing trends were mainly distributed in the east in most growth stages. (3) Sunshine hours and temperature had a greater impact on the maize WF in most growth stages. The impacts of other climatic factors on the WF of rain-fed maize differed among different growth stages. Precipitation contributed much more to the variation in maize WF in early growth stages, relative humidity had the greatest impact on the WF of maize in the jointing-tasseling growth stage, and wind speed played a major role in the variation in the maize WF at the milky-mature growth stage. Management measures should be adjusted to alleviate the impact of climatic conditions on crop water consumption in different growth stages according to the results. • Water footprint (WF) of rain-fed maize in different growth stages was analyzed. • The highest WF was in tasseling-milky stage and the lowest in sowing-seeding stage. • Sunshine hours and temperatures had a greater impact on WF in most growth stages. • Feasible measures to reduce the impact of climatic factors on WF were discussed. [ABSTRACT FROM AUTHOR]