Chin J Plant Ecol ›› 2018, Vol. 42 ›› Issue (10): 1033-1042.DOI: 10.17521/cjpe.2018.0067

• Research Articles • Previous Articles     Next Articles

Characteristics of soil water distribution and evaluation of recharge rate under different grazing history in the Xilin Gol Steppe

LI Jin-Bo1,YAO Nan1,ZHAO Ying1,2,*(),FAN Ting1,ZHANG Jian-Guo1,LAN Zhi-Long1,YI Jun1,SI Bing-Cheng2   

  1. 1 Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Collage of Natural Resource and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China;
    2 School of Resources and Environmental Engineering, Ludong University, Yantai, Shandong 264025, China
  • Received:2018-03-29 Online:2018-10-20 Published:2018-09-26
  • Contact: Ying ZHAO
  • Supported by:
    Supported by the National Natural Science Foundation of China(41371234)

Abstract:

Aims In the Xilin Gol Steppe, human-induced grassland degradation and land desertification are becoming increasingly severe. Critical evaluation of its impact on soil water and recharge rate is important for sustainable management of soil health and water resources in the region.
Methods In order to determine the effect of different grazing history on dynamics of deep soil moisture contents and precipitation infiltration in the Xilin Gol Steppe, three sites with different grazing history (ungrazed since 1979 or UG79, ungrazed since 1999 or UG99, and continuously grazed or CG) were selected with two sampling spots for each site. The precipitation infiltration was estimated using the chloride mass balance method.
Important findings The results showed that: 1) Average soil water content of 0-5 m was 7.1%, 6.9%, and 6.3% for UG79, UG99, and CG, respectively, with no significant difference. In the soil layer of 0-2 m, the soil water content of UG79 was 26.6% and 33.7% higher than that of UG99 and CG, respectively. The soil water content of UG79 was significantly higher than that of UG79 and UG99 (p < 0.05) with no significant difference between UG99 and CG. The soil water storage capacity of UG79 was 87.19 mm higher than UG99 and 82.52 mm higher than CG. In the deep layer of 2-5 m, no significant difference in the soil water content and the water storage among different grazing history. 2) The factors influencing soil water differed among different grazing treatments. The soil water content was mainly affected by the vegetation conditions and soil properties for the 0-2 m soil layer, but by the composition of soil particles for the 2-5 m soil layer. The effect of soil organic matter (SOM) content on soil water increased with time without grazing. Soil water content of the entire soil profile of UG79 was significantly correlated with soil texture and SOM content (p < 0.01). Soil water content of 0-2 m was significantly correlated with SOM content (p < 0.01), soil water content of 2-5 m was significantly correlated with the soil texture (p <0.01), but soil moisture content of UG99 and CG had no significant correlation with SOM content. 3) Annual recharge rate was 5.64, 3.54, and 2.45 mm·a -1 for UG79, UG99 and CG, respectively. The recharge rate increased by 44.5% and 130.2% for the site without grazing for 15 and 35 years, respectively. The recharge rate in the study area ranged from 1.95 to 7.61 mm·a -1, accounting for only 0.55%-2.13% of the precipitation. In summary, ungrazing treatment can increase soil water retention, total water storage capacity, and recharge.

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Key words: soil moisture, recharge rate, steppe, Chloride Mass Balance