Using stable isotopes to determine seasonal variations in water uptake of summer maize under different fertilization treatments

作者：Ying Ma, Xianfang Song · 发表于：The Science of The Total Environment · 年份：2016 · DOI：10.1016/j.scitotenv.2016.01.148 · 被引用次数：133 · 研究领域：Isotope Analysis in Ecology、Crop Yield and Soil Fertility、Archaeology and ancient environmental studies

Fertilization and water both affect root water uptake in the nutrient and water cycle of the Soil-Plant-Atmosphere-Continuum (SPAC). In this study, dual stable isotopes (D and (18)O) were used to determine seasonal variations in water uptake patterns of summer maize under different fertilization treatments in Beijing, China during 2013-2014. The contributions of soil water at different depths to water uptake were quantified by the MixSIAR Bayesian mixing model. Water uptake was mainly sourced from soil water in the 0-20cm depth at the seeding (67.7%), jointing (60.5%), tasseling (47.5%), dough (41.4%), and harvest (43.9%) stages, and the 20-50cm depth at the milk stage (32.8%). Different levels of fertilization application led to considerable differences in the proportional contribution of soil water at 0-20cm (6.0-58.5%) and 20-50cm (6.1-26.3%). There was little difference of contributions in the deep layers (50-200cm) among treatments in 2013, whereas differences were observed in 50-90cm at the milk stage and 50-200cm at the dough stage during 2014. The main water uptake depth was concentrated in the upper soil layers (0-50cm) during the wet season (2013), whereas a seasonal drought in 2014 promoted the contribution of soil water in deep layers. The contribution of soil water was significantly and positively correlated with the proportions of root length (r=0.753, p<0.01). The changes of soil water distribution were consistent with the seasonal variation in water uptake pat...