生态环境学报 ›› 2023, Vol. 32 ›› Issue (8): 1507-1515.DOI: 10.16258/j.cnki.1674-5906.2023.08.016

• 研究论文【环境科学】 • 上一篇    下一篇

沼液还田下不同种植模式的重金属风险评价及安全消纳量分析

刘炳妤1(), 王一佩1, 姚作芳2, 杨钙仁1,3,*(), 徐晓楠1, 邓羽松1,3, 黄钰涵1,3   

  1. 1.广西大学林学院,广西 南宁 530004
    2.中国科学院科技创新发展中心,北京 100190
    3.广西大学林学院/广西森林生态与保育重点实验室,广西 南宁 530004
  • 收稿日期:2023-02-21 出版日期:2023-08-18 发布日期:2023-11-08
  • 通讯作者: *杨钙仁。E-mail: yanggr@gxu.edu.cn
  • 作者简介:刘炳妤(1998年生),女,硕士研究生,从事自然保护地管理与生态修复技术研究。E-mail: 549540424@qq.com
  • 基金资助:
    广西重点研发计划项目(桂科AB22080103);广西创新驱动发展项目(桂科AA17204078-3);广西创新驱动发展项目(桂科AA17204087-8)

Risk Assessment and Safe Consumption Analysis of Heavy Metals under Different Planting Patterns of Biogas Slurry

LIU Bingyu1(), WANG Yipei1, YAO Zuofang2, YANG Gairen1,3,*(), XU Xiaonan1, DENG Yusong1,3, HUANG Yuhan1,3   

  1. 1. College of Forestry, Guangxi University, Nanning 530004, P. R. China
    2. Scientific and Technological Innovation and Development Center, Beijing 100190, P. R. China
    3. Guangxi Key Laboratory of Forest Ecology and Conservation/College of Forestry, Guangxi University, Nanning 530004, P. R. China
  • Received:2023-02-21 Online:2023-08-18 Published:2023-11-08

摘要:

为探讨沼液中重金属对土壤质量、农林作物安全生产的影响,评价施用沼液对土壤环境与农林作物污染的风险,以及提出不同种植模式的沼液适宜用量,在广西壮族自治区主要生猪养殖区,选择蔬菜、果树、牧草、用材林等不同类型的耕地13个,采集0-20 cm和20-40 cm土层土壤样品以及部分植物的根系、茎秆、叶片、果实等,测定上述样品的Cu、Zn、Pb、Cd、Cr等元素的含量,分析和评价土壤、农林作物的污染状况。结果显示:13个样点中,0-20 cm和20-40 cm土壤的Cu、Zn污染样点比例相同,分别为46.2%和38.5%,高于Pb、Cd、Cr;0-20、20-40 cm土壤的Cu、Zn污染指数,以及0-20 cm土壤内梅罗综合污染指数与沼液浇灌总量呈显著正相关,而与年均浇灌量相关性不显著;耕地土壤5种元素的沼液消纳容量大小为Cr>Pb>Zn>Cu>Cd。9个可供食用的植物样点中,Pb含量超标的样点数最多,其次是Cr,占比分别为66.7%和44.4%;内梅罗综合污染指数处于污染的样点比例为88.9%。杂交象草((Pennisetum americanum×P. purpureumP. durpureum schum cv. Guimu No.1)各项污染指数比较小,污染程度较轻。施用沼液对土壤的主要污染风险是Cu和Zn,主要位于0-20 cm土层;对叶类蔬菜和木本水果的主要污染风险是Pb,其次是Cr,浇灌沼液对杂交象草的重金属污染风险较小。不同耕地类型对沼液的消纳容量大小为杂交象草>速生用材树>叶类蔬菜>木本果树。

关键词: 沼液还田, 重金属, 土壤污染, 农林作物污染, 污染评价

Abstract:

This study investigates the impact of heavy metals present in biogas slurry on soil health and the secure cultivation of agricultural and forestry crops. By evaluating potential risks to soil and crop health due to biogas slurry utilization, we aim to suggest suitable quantities of biogas slurry for various planting methods. To this end, we selected 13 different types of cultivated lands, including vegetable farms, fruit orchards, grasslands, and timber forests, in primary pig farming regions of the Guangxi Zhuang Autonomous Region. We measured the levels of Cu, Zn, Pb, Cd, and Cr in soil layers (0?20 cm and 20?40 cm) and in plant components such as roots, stems, leaves, and fruits. Next, we analyzed and evaluated soil and crop contamination levels and recommended a safe absorption capacity for biogas slurry in cultivated land. The findings revealed that the contamination proportions of Cu and Zn in both soil layers were identical, at 46.2% and 38.5%, respectively, surpassing Pb, Cd, and Cr. Notably, the pollution indices for Cu and Zn in both soil layers and the overall pollution index of the 0?20 cm soil layer were positively correlated with the total biogas slurry irrigation. Yet, there was no significant correlation with the average annual irrigation amount. In terms of the absorption capacity of biogas slurry in cultivated soil, the order was Cr>Pb>Zn>Cu>Cd. Among nine edible plant samples, Pb was the most prevalent heavy metal, followed by Cr, accounting for 66.7% and 44.4%, respectively. The contamination index of hybrid elephant grass (Pennisetum americanum×P. purpureum×P. purpureum schum, cv. Guimu No.1) was smaller, indicating lighter pollution. The most significant pollution risks from biogas slurry application to soil were Cu and Zn, primarily found in the 0?20 cm soil layer. The primary contamination risk for leaf vegetables and woody fruits was Pb, followed by Cr. Hybrid elephant grass exhibited a lower risk of heavy metal pollution when irrigated with biogas slurry. In conclusion, the capacity to consume biogas slurry varies across different types of cultivated land, with the order being: hybrid elephant grass > fast-growing timber tree > leafy vegetables>woody fruit tree.

Key words: returning biogas slurry to the field, heavy metals, soil pollution, contamination of agricultural and forestry crops, pollution assessment

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