Synergistic effect on soil health from combined application of biogas slurry and biochar

Xiaoyang Liang; Chuanjuan Wang; Haitao Wang; Xuefeng Qiu; Hongxu Ji; Hui Ju; Jiandong Wang

doi:10.1016/j.chemosphere.2023.140228

Synergistic effect on soil health from combined application of biogas slurry and biochar

Chemosphere. 2023 Dec:343:140228. doi: 10.1016/j.chemosphere.2023.140228. Epub 2023 Sep 22.

Authors

Xiaoyang Liang¹, Chuanjuan Wang¹, Haitao Wang², Xuefeng Qiu², Hongxu Ji³, Hui Ju⁴, Jiandong Wang⁵

Affiliations

¹ Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, Xinjiang, 831100, China; Key Laboratory of Low-carbon Green Agriculture in North China, Ministry of Agriculture and Rural Affairs, China.
² Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Key Laboratory of Low-carbon Green Agriculture in North China, Ministry of Agriculture and Rural Affairs, China.
³ Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China.
⁴ Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
⁵ Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Key Laboratory of Low-carbon Green Agriculture in North China, Ministry of Agriculture and Rural Affairs, China. Electronic address: wangjiandong@caas.cn.

PMID: 37742761
DOI: 10.1016/j.chemosphere.2023.140228

Abstract

Biogas slurry and biochar, as typical by-products and derivatives of organic waste, have been applied in agricultural production to improve the soil carbon (C) pool. However, whether the combined application of biogas slurry and biochar produces synergistic effects on the soil C pool and soil health requires quantitative clarification. In this study, we performed a pot experiment to analyze the changes of soil organic carbon (SOC), potassium permanganate-oxidized carbon (POXC), mineralizable carbon (MC), soil β-glucosidase (S-β-GC), and soil protein (SP) in different treatments at the flowering and fruit-setting stages, and full fruit stage of tomato by establishing two base fertilizer modes (base fertilizer N and base biogas slurry N), three topdressing modes (topdressing chemical fertilizer N, topdressing 50% biogas slurry N + 50% chemical fertilizer N, and topdressing biogas slurry N), and two biochar levels (no addition and 3% biochar addition). During the full fruit period, the SOC content of bottom applications of biogas slurry and topdressings of biogas slurry significantly increased by 9.92-15.52% and 13.02-18.26%, respectively (P < 0.05), when compared to chemical fertilizer bottom applications and topdressings of chemical fertilizer. When compared to non-biochar treatment, the SOC content of the biochar considerably increased by 52.56-58.94% (P < 0.05). Moreover, biogas slurry treatment increased the MC, steady-state C, and C pool index, and decreased the S-β-GC, C pool efficiency, C pool activity, and C pool activity index. Application of biogas slurry initially reduced POXC, SP, the C pool management index, and the soil quality index; nonetheless, these indicators eventually recovered or even exceeded the result of single application chemical fertilizer. Overall, the combined application of biogas slurry and biochar strongly increases the soil C pool, improves soil health, and reduces the short-term negative effects of using only biogas slurry.

Keywords: Biochar; Biogas slurry; Soil carbon pool; Soil health.