| 摘要: |
| 【目的】明确砂田表层土壤微生物生物量与酶活性对连作的生态响应规律及其退化演替特征。【方法】通过收集整理330组中国西北旱区连作砂田的田间取样或野外调查数据，借助Meta-analysis方法进行整合定量研究，定量分析覆砂1~3 a农田与其他连作砂田（4~6、7~9、10~12、13~15 a）在表层土壤微生物生物量与酶活性方面的差异效应，系统阐释连作砂田表层土壤微生物活性与养分因子间的协同变化关系，进而从生境土壤微生物的角度综合评估其土壤健康水平。【结果】与短期覆砂（1~3 a）相比，长期覆砂（4~15 a）对砂田表层土壤微生物生物量各项指标与多种酶活性均具有不同程度的抑制效果，其中，细菌数量、真菌数量、放线菌数量、微生物总量、细菌与真菌的数量比值、微生物生物量碳、微生物生物量氮、微生物生物量碳氮比以及脲酶、磷酸酶、蔗糖酶活性的整体降幅分别可达39.35%、12.99%、58.34%、42.13%、30.11%、56.43%、25.45%、32.75%、40.77%、18.42%、32.89%，且这种负向效应伴随种植年限的增加而愈加强烈（P＜0.05）；而土壤过氧化氢酶活性则同比增加1.27%（P＜0.05）。【结论】连作显著增加砂田表层土壤微生物活性的长期变异性，连作4~6 a时其退化状态初显，连作10~12 a时，土壤微生物活性的衰退过程则愈加严重。 |
| 关键词: 砂田；连作；土壤微生物活性；退化；中国西北旱区；整合分析 |
| DOI：10.13522/j.cnki.ggps.2024380 |
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| Impact of continuous cropping on microbial biomass and enzyme activities in the surface layer of gravel-sand mulched soils in arid Northwest China: A Meta-analysis |
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XUE Yinmin, JIA Zhenjiang, MA Dongxiang, WU Yangyang, HUANG Yahao,HE Xuezhong,WU Xiu,LI Wangcheng
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1. Ningxia Zhongwei Water Conservancy Survey and Design Institute, Zhongwei 755000, China;
2. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China; 3. Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions, Ministry of Education, Yinchuan 750021, China;
4. State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China, Yinchuan 750021, China;
5. Key Laboratory of the Internet of Water and Digital Water Governance of the Yellow River in Ningxia, Yinchuan 750021, China
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| Abstract: |
| 【Objective】Soil microorganisms and enzymes play crucial roles in nutrient cycling and maintaining soil health, and their activities are influenced by various abiotic and biotic factors. This study uses meta-analysis to investigates the impact of long-term continuous cropping on microbial biomass and enzyme activities in the surface layer of gravel-sand mulched soils in arid regions of Northwestern China.【Method】Microbial indicators extracted from the literature included total bacterial count (TBC), total fungal count (TFC), total actinomycetes count (TAC), total microbial count (TMC), the bacteria-to-fungi ratio (TBC∶TFC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and the MBC∶MBN ratio. Enzymatic indicators extracted from the literature were activities of catalase (CAT), urease (URE), phosphatase (PHO), and sucrase (SUR). Fields mulched with gravel for 1-3 years served as the control (CK). Pearson correlation analysis was used to examine the relationships between microbial activity and soil nutrient factors such as soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and available potassium (AK).【Result】Compared to the control, long-term continuous cropping (4-15 years) significantly (P＜0.05) reduced TBC, TFC, TAC, TMC, TBC∶TFC, MBC, MBN, MBC∶MBN, and the activities of URE, PHO, and SUR by 39.35%, 12.99%, 58.34%, 42.13%, 30.11%, 56.43%, 25.45%, 32.75%, 40.77%, 18.42%, and 32.89%, respectively. These negative effects intensified with increasing cropping duration. In contrast, continuous cropping increased CAT activity by an average of 1.27% (P＜0.05), likely due to the changes in soil nutrients.【Conclusion】Continuous cropping for 4-6 years significantly affects topsoil microbial activity in gravel-sand mulched fields, leading to early signs of soil degradation. These findings highlight the need for optimized cropping strategies and improving soil management to sustain microbial function and soil fertility in arid and semi-arid agricultural systems in Northwestern China. |
| Key words: gravel-sand mulched field; continuous cropping; soil microbial activity; degradation; arid regions of Northwest China; Meta-analysis |
