How effective are soil and water conservation measures (SWCMs) in reducing soil and water losses in the red soil hilly region of China? A meta-analysis of field plot data

Jia Chen; Haibing Xiao; Zhongwu Li; Cheng Liu; Ke Ning; Chongjun Tang

doi:10.1016/j.scitotenv.2020.139517

How effective are soil and water conservation measures (SWCMs) in reducing soil and water losses in the red soil hilly region of China? A meta-analysis of field plot data

Sci Total Environ. 2020 Sep 15:735:139517. doi: 10.1016/j.scitotenv.2020.139517. Epub 2020 May 19.

Authors

Jia Chen¹, Haibing Xiao², Zhongwu Li³, Cheng Liu⁴, Ke Ning⁵, Chongjun Tang⁶

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Science, Beijing 100049, China.
² College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
³ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China; College of Resources and Environmental Sciences, Hunan Normal University, Changsha 410081, China; College of Environmental Science and Engineering, Hunan University, Changsha 410082, China. Electronic address: lizw@hnu.edu.cn.
⁴ International Research and Training Center on Erosion and Sedimentation, Beijing 100044, China.
⁵ College of Resources and Environmental Sciences, Hunan Normal University, Changsha 410081, China; College of Environmental Science and Engineering, Hunan University, Changsha 410082, China.
⁶ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Science, Beijing 100049, China; Jiangxi Institute of Soil and Water Conservation, Jiangxi Provincial Key Laboratory of Soil Erosion and Prevention, Nanchang 330029, China.

PMID: 32470675
DOI: 10.1016/j.scitotenv.2020.139517

Abstract

Anthropogenic pressure coupled with high rainfall and diverse heterogeneous landscapes (e.g., land use and topography) has resulted in severe water erosion in the red soil hilly region (RSHR) of China. Soil and water conservation measures (SWCMs) have been extensively implemented, and their effects on runoff and sediment control have been widely tested at plot scales. However, it is difficult to gain an overview of the efficiency of SWCMs due to the difficulty of directly upscaling field observations to regional scales. We conducted a meta-analysis of 498 field plots covering 53 sites in the RSHR to evaluate the efficiency of different SWCMs and identify optimal conservation practices. The results were as follows: (i) SWCMs involving erosion control (92%) had a greater efficiency than those focusing on runoff reduction (73%). (ii) The implementation of combined measures was more effective than single measures for reducing runoff and soil loss. (iii) All thirty SWCMs showed a significant effect with respect to runoff and sediment control, except for contour tillage effect on reduction of soil loss. (iv) The maximum and minimum ratios between runoff and sediment reduction were found in orchard and cropland, respectively. (v) Six measures, mulching, tree crop + grass, tree crop + hedgerows, tree crop + grass cover + terrace, tree crop + hedgerows + terrace and hedgerows + contour tillage, can be recommended as high effective SWCMs in the RSHR. This study provides a systematic overview quantifying the factors controlling the effectiveness of SWCMs in the RSHR and can serve as a scientific foundation enabling decision makers to implement suitable SWCMs in mitigating land degradation due to water erosion.

Keywords: Meta-analysis; Runoff plots; Runoff reduction; Soil and water conservation measures; Water erosion control.