Resources Science ›› 2018, Vol. 40 ›› Issue (4): 818-828.doi: 10.18402/resci.2018.04.15

• Orginal Article • Previous Articles     Next Articles

Water movement through unsaturated zones in the severe saline-alkali cotton fields in inland arid regions underwater and salt regulation by drip irrigation

Tiantian ZHOU1,2(), Dongmei HAN1,2(), Xianfang SONG1,2, Ying MA1,2, Yinghua ZHANG1   

  1. 1. Key Laboratory of Water Cycle and the Surface Process, Institute of Geographical Science and Natural Resources, Chinese Academy of Sciences, Beijing 100101, China
    2. School of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-09-18 Revised:2018-02-08 Online:2018-05-02 Published:2018-05-02

Abstract:

The study of water movement through unsaturated zones provides a theoretical basis for water and salt regulation by drip irrigation in arid zone. Here, we took the improved severe saline-alkali cotton field by this schedule in Karamay agricultural development area as an example. Based on in-situ observations of soil water potential, soil water content and stable isotopes in water during different cotton growth periods, we studied water movement characteristics through an unsaturated zone. The results show that under water and salt regulation by drip irrigation schedules, 0~60 cm in the improved severe saline-alkali cotton field is influenced by infiltration and evapotranspiration, and soil water content varies with time. 60~220 cm is less influenced by infiltration compared with 0~60 cm, along with comparatively stable dynamics in soil water content, soil water potential and isotopic compositions of soil water. 220~260 cm is obviously affected by groundwater, along with more stable dynamics of soil water content, soil water potential and isotopic compositions of soil water compared with 60~220 cm. Precipitation and irrigation water account for about 22% and 78% of soil water at 120cm and 150cm, respectively, accounting for 40% and 60% of soil water at 100cm and 180cm, respectively and 46% and 54% of soil water at 260cm. Irrigation water has no significant impacts on groundwater. Water table changes during this experiment period mainly came from lateral groundwater recharge.

Key words: arid zone, saline-alkali soil, stable, drip irrigated isotopes cotton fields, stable, unsaturated zone, groundwater recharge, Karamay agricultural development area