[1]CHENG Liping,QI Guang,LI Yanjiao,et al.Stable Isotope Analysis of Soil Water Utilization by Winter Wheat in Dryland of Loess Tableland[J].Research of Soil and Water Conservation,2021,28(03):170-176.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
28
Number of periods:
2021 03
Page number:
170-176
Column:
Public date:
2021-04-20
- Title:
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Stable Isotope Analysis of Soil Water Utilization by Winter Wheat in Dryland of Loess Tableland
- Author(s):
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CHENG Liping1, QI Guang1, LI Yanjiao1, LIU Wenzhao2
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(1.Pingdingshan University, Pingdingshan, He'nan 467000, China; 2.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China)
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- Keywords:
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loess tableland; soil water; stable hydrogen and oxygen isotopes; IsoSource model
- CLC:
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S152.7,S314
- DOI:
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- Abstract:
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In this paper, soil water at the depth of 300cm both in the rain cover plot and the natural plot in Changwu Loess Tableland were marked by deuterium water, and the δD and δ18 O values of wheat stem water, rainwater and soil water samples in different layers in different growth stages of winter wheat were measured to determine whether winter wheat can use the soil water in 300cm depth. Further, the utilization of soil water in different soil layers by winter wheat in dryland and its response to the reduction of precipitation were analyzed. The results show that:(1)winter wheat begins to use soil water in 300cm depth since the flowering-filling stages, and the utilization of soil water in different soil layers decrease with the increase of soil depth;(2)from the heading stage to the milk, the contribution rates of soil water in 0—50cm, 50—100 cm, 100—200cm and 200—300cm layer to the water consumption of winter wheat were 28.0%~36.7%, 24.7%~32.3%, 15.7%~22.3% and 11.4%~17.4%, respectively, and the contribution rate of soil water in 300—400 cm depth was 15.6%~16.6% during the filling and milk ripening stages;(3)reduction of precipitation dose not change the time of winter wheat use soil water in 300cm depth, but increases the utilization rate of soil water from deep soil layer, so as to meet the water demand during the growing period. Overall, soil water storage in deep layer is significant for winter wheat in dryland of the loess tableland. Therefore, it is necessary to take effective measures to improve the soil water storage during the fallow period in summer in production practice, so as to promote the recovery of soil water in deep layer and maintain sustainable regulation and storage function of the soil reservoir.