Effects of grazing and enclosure management on soil physical and chemical properties vary with aridity in China's drylands

Wenxin Zhou; Changjia Li; Shuai Wang; Zhuobing Ren; Lindsay C Stringer

doi:10.1016/j.scitotenv.2023.162946

Effects of grazing and enclosure management on soil physical and chemical properties vary with aridity in China's drylands

Sci Total Environ. 2023 Jun 15:877:162946. doi: 10.1016/j.scitotenv.2023.162946. Epub 2023 Mar 21.

Authors

Wenxin Zhou¹, Changjia Li², Shuai Wang¹, Zhuobing Ren¹, Lindsay C Stringer³

Affiliations

¹ State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China; Institute of Land Surface System and Sustainable Development, Faculty of Geographical Science, Beijing Normal University, Beijing, China.
² State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China; Institute of Land Surface System and Sustainable Development, Faculty of Geographical Science, Beijing Normal University, Beijing, China. Electronic address: changjia.li@bnu.edu.cn.
³ Department of Environment and Geography, University of York, York, UK; York Environmental Sustainability Institute, University of York, York, UK.

PMID: 36948320
DOI: 10.1016/j.scitotenv.2023.162946

Abstract

Dryland soils are nutrient-poor and prone to degradation due to aridity, grazing and enclosure. It is essential to examine the effects of grazing and enclosure on aridity-induced soil degradation in dryland ecosystems to optimize land management practices in response to climate change. However, quantitative evaluation on this topic is scarce due to a lack of long-term field monitoring data. This study evaluated the combined effects of aridity and grazing/enclosure using long-term data (2005-2015) from three research stations on soil physical and chemical properties in typical steppes and desert steppes across the semi-arid and hyper-arid areas of China's drylands. Results showed that soil organic matter (OM) content was higher for enclosures (20.50 g/kg) than for grazing (19.06 g/kg). In the semi-arid steppe, enclosures aged 30-33 years had the highest soil total nitrogen (TN) content (1.21 g/kg). Longer enclosures aged 34-36 years showed decreased soil TN content (0.88 g/kg). In the desert steppe, enclosures aged 5-8 years exhibited the highest soil OM (2.44 g/kg) and TN (0.21 g/kg) contents. Grazing enhanced the decrease of OM content (from 4.57 to 2.39 g/kg) with increasing aridity (1 - aridity index) from 0.35 to 1. These findings indicate that enclosures can improve soil fertility, but prolonged enclosures may have negative effects. Grazing had a synergistic effect on the decrease of OM with aridity. Results can be used in response to climate changes to formulate sustainable land management strategies, such as reducing the enclosure period in wetter and restored areas, and diminishing the grazing intensity in areas with higher aridity.

Keywords: Desert steppe; Fence off; Land use; Rangeland; Semi-arid steppe; Soil characteristic.