| Contributions of soil water in deep soil layers to water consumption of dryland winter wheat on the Loess Tableland |
|
View Fulltext View/Add Comment Download reader |
| |
| DOI：10.7606/j.issn.1000-7601.2020.05.20 |
| Key Words: dryland winter wheat moisture source contribution rate of water consumption stable isotope Loess tableland |
| Author Name | Affiliation | | CHENG Liping | Pingdingshan College, Pingdingshan, Henan 467000, China | | LIN Wen | College of Agriculture, Shanxi Agricultural University, Taigu, Shanxi 030801, China | | WANG Yaping | State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, Shaanxi 712100, China | | LIU Wenzhao | State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, Shaanxi 712100, China |
|
| Hits: 732 |
| Download times: 457 |
| Abstract: |
| In order to study the contributions of water in different soil layers, especially deep soil, on the water consumption of winter wheat, the soil water at the depth of 300 cm was marked by deuterium water, and the δD values of wheat stem water at heading, flowering, filling, and milk\|ripening stages were measured to determine whether winter wheat can make use of the soil water below the depth of 300 cm in Changwu Loess Tableland. Additionally, we measured the δ18O values of wheat stem water, rainwater, and soil water in 0~400 cm soil profile to analyze the contribution rates of rainwater and soil water in different soil layers to water consumption of winter wheat. The results showed that the contribution rates of rainwater to wheat water consumption at heading, flowering, filling, and milk\|ripening stages were 49.2%, 30.2%, 35.9%, and 38.2%, respectively, and these of soil water were 50.8%, 69.7%, 64.1%, and 61.8%, respectively. The contribution rates of soil water stored in different soil layers (50~100 cm, 100~150 cm, 150~200 cm, and 200~300 cm depths) to wheat water consumption were 17.9%, 15.2%, 10.0%, and 7.7% at heading stage, 24.6%, 18.8%, 14.0%, and 12.4% at flowering stages, 19.5%, 14.4%, 10.0%, and 8.7% at filling stages and 18.6%, 13.2%, 10.3%, and 8.3% at milk\|ripening stage, respectively. The variation of δD values of stem water indicated that winter wheat began to use soil water storage below the depth of 300 cm since the filling stages. And the soil water stored in 300~400 cm deep contributed 11.4% and 11.5% to winter water consumption at filling and milk\|ripening stage, respectively. Overall, soil water storage in the deep layer was a significant water supply to dryland winter wheat in Loess Tableland. Therefore, it is necessary to take effective measures in water storage and conservation, as well as increase the amount and depth of rainwater infiltration during the summer fallow period in production practice, so as to promote the recovery of soil water in deep layer and maintain the sustainable regulation and storage function of soil reservoir. |
|
|
|