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Zhang J, Duan Q, Ma J, Hou F. Nitrogen mineralization in grazed BSC subsoil is mediated by itself and vegetation in the Loess Plateau, China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 336:117647. [PMID: 36905690 DOI: 10.1016/j.jenvman.2023.117647] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Biological soil crust (BSC) exists widely in many kinds of grassland, its effect on soil mineralization in grazing systems has well been studied, but the impacts and threshold of grazing intensity on BSC have rarely been reported. This study focused on the dynamics of nitrogen mineralization rate in biocrust subsoils affected by grazing intensity. We studied the changes in BSC subsoil physicochemical properties and nitrogen mineralization rates under four sheep grazing intensities (i.e., 0, 2.67, 5.33, and 8.67 sheep ha-1) in seasons of spring (May-early July), summer (July-early September), and autumn (September-November). Although this moderate grazing intensity contributes to the growth and recovery of BSCs, we found that moss was more vulnerable to trampling than lichen, which means the physicochemical properties of the moss subsoil are more intense. Changes in soil physicochemical properties and nitrogen mineralization rates were significantly higher under 2.67-5.33 sheep ha-1 than other grazing intensities (Saturation phase). In addition, the structural equation model (SEM) showed that the main response path was grazing, which affected subsoil physicochemical properties through the joint mediation of BSC (25%) and vegetation (14%). Then, the further positive effect on nitrogen mineralization rate and the influence of seasonal fluctuations on the system was fully considered. We found that solar radiation and precipitation all had significant promoting effects on soil nitrogen mineralization rates, the overall seasonal fluctuation has a direct effect of 18% on the rate of nitrogen mineralization. This study revealed the effects of grazing on BSC and the results may enable a better statistical quantification of BSC functions and provide a theoretical basis to formulate grazing strategies in the grazing system of sheep in Loess Plateau even worldwide (BSC symbiosis).
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Affiliation(s)
- Jing Zhang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Lanzhou University, Lanzhou, 730020, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Qianwen Duan
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Lanzhou University, Lanzhou, 730020, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Jie Ma
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Lanzhou University, Lanzhou, 730020, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Fujiang Hou
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Lanzhou University, Lanzhou, 730020, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China.
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Ji C, Huang J, Tian Y, Liu Y, Barvor JB, Shao X, Li Z. Feasibility Study on the Application of Microbial Agent Modified Water-Jet Loom Sludge for the Restoration of Degraded Soil in Mining Areas. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:6797. [PMID: 34202710 PMCID: PMC8296874 DOI: 10.3390/ijerph18136797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/16/2021] [Accepted: 06/16/2021] [Indexed: 11/29/2022]
Abstract
Open-pit mining causes soil damage and affects the health of the ecosystem. In the arid grassland mining areas, the soil is severely sanded, water-starved, and saline, thus making it difficult for plants and microorganisms to survive. Water-jet loom sludge can be used to improve the quality as it contains a lot of clay and is rich in organic matter, which provides a material basis for microorganism activity. To explore the effects of microbial agent-modified water-jet loom sludge on the restoration of degraded soil in grassland mining areas, four pot trials were set up, i.e., for untreated soil, the application of a microbial agent alone, the application of water-jet loom sludge alone, and the combined application of water-jet loom sludge and the microbial agent. The results show that (1) microbial agent-modified sludge can improve soil water-holding capacity and aggregate stability; (2) the nutrient content of the restored soil fraction increased significantly, and the pH of the original saline soil decreased from 9.06 to 7.84; (3) this method significantly increased plant biomass and microbial biomass carbon and enhanced the abundance and diversity of fungi and bacteria. The three treatments had different results in different soil properties, and the effect of the combined water-jet loom sludge and microbial agent treatment on soil remediation was significantly better than the individual application of either.
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Affiliation(s)
- Chuning Ji
- Engineering Research Center of Ministry of Education for Mine Ecological Restoration, China University of Mining and Technology, Xuzhou 221116, China; (C.J.); (Y.T.); (J.B.B.); (X.S.); (Z.L.)
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
| | - Jiu Huang
- Engineering Research Center of Ministry of Education for Mine Ecological Restoration, China University of Mining and Technology, Xuzhou 221116, China; (C.J.); (Y.T.); (J.B.B.); (X.S.); (Z.L.)
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
| | - Yu Tian
- Engineering Research Center of Ministry of Education for Mine Ecological Restoration, China University of Mining and Technology, Xuzhou 221116, China; (C.J.); (Y.T.); (J.B.B.); (X.S.); (Z.L.)
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
| | - Ying Liu
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
- School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China
| | - Joshua Bosco Barvor
- Engineering Research Center of Ministry of Education for Mine Ecological Restoration, China University of Mining and Technology, Xuzhou 221116, China; (C.J.); (Y.T.); (J.B.B.); (X.S.); (Z.L.)
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
| | - Xintong Shao
- Engineering Research Center of Ministry of Education for Mine Ecological Restoration, China University of Mining and Technology, Xuzhou 221116, China; (C.J.); (Y.T.); (J.B.B.); (X.S.); (Z.L.)
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
| | - Zi’ao Li
- Engineering Research Center of Ministry of Education for Mine Ecological Restoration, China University of Mining and Technology, Xuzhou 221116, China; (C.J.); (Y.T.); (J.B.B.); (X.S.); (Z.L.)
- School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China;
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