Comparing combined application of biochar and nitrogen fertilizer in paddy and upland soils: Processes, enhancement strategies, and agricultural implications

Xiaomai Yuan; Xiaoyan Gu; Run Liang; Guichen Ban; Li Ma; Tieguang He; Ziting Wang

doi:10.1016/j.scitotenv.2024.173160

Comparing combined application of biochar and nitrogen fertilizer in paddy and upland soils: Processes, enhancement strategies, and agricultural implications

Sci Total Environ. 2024 May 11:933:173160. doi: 10.1016/j.scitotenv.2024.173160. Online ahead of print.

Authors

Xiaomai Yuan¹, Xiaoyan Gu², Run Liang¹, Guichen Ban¹, Li Ma¹, Tieguang He³, Ziting Wang⁴

Affiliations

¹ State Key Laboratory for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi University, Nanning 530004, Guangxi, PR China; College of Agronomy, Guangxi University, Nanning 530004, Guangxi, PR China; Guangxi Key Laboratory of Sugarcane Biology, Nanning 530004, Guangxi, PR China.
² Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, Hunan, PR China.
³ Agricultural Resources and Environmental Research Institute, Guangxi Academy of Agricultural Sciences/Guangxi Key Laboratory of Arable Land Conservation, Nanning 530007, Guangxi, PR China.
⁴ State Key Laboratory for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi University, Nanning 530004, Guangxi, PR China; College of Agronomy, Guangxi University, Nanning 530004, Guangxi, PR China; Guangxi Key Laboratory of Sugarcane Biology, Nanning 530004, Guangxi, PR China. Electronic address: zitingwang@gxu.edu.cn.

PMID: 38735324
DOI: 10.1016/j.scitotenv.2024.173160

Abstract

Recently, biochar and N fertilizers have been used to tackle low N use efficiency (NUE) in crops across diverse environmental conditions. The coupling of biochar and N fertilizer may impact crop N utilization through different pathways in various soil types. However, there is currently a lack of comprehensive assessment of how coupling effects specifically influence N utilization in paddy and upland crops. We conducted a meta-analysis of 175 peer-reviewed studies to assess the responses of soil properties and crop traits in paddy and upland fields under coupling effects. The results indicate that NUE (+26.1 %) and N uptake (+15.0 %) in paddy fields increase more than in upland fields (+23.7 % and +8.0 %, respectively), with the coupling effect providing NH₄⁺ predominantly for rice and NO₃^- for upland crops. NH₄⁺ increases in paddy fields (+6.9 %) but decreases in upland fields (-0.7 %), while microbial biomass carbon (MBC) decreases in paddy fields (-2.9 %) and increases in upland fields (+36.0 %). These findings suggest that coupling effects supply soil inorganic nutrients in paddies and affect microbes in uplands, thereby positively affecting crop N utilization. Specifically, the greatest increase in paddy crop yield and N use efficiency occurs when the ratio of N fertilizer to biochar exceeds 1.5 %, and in uplands, it manifests when applying 10-20 t·ha^-1 of biochar and <150 kg·ha^-1 N fertilizer. In conclusion, this meta-analysis explores the differential effects of biochar and N fertilizer coupling in different arable land types, offering novel insights into the utilization strategies of biochar in agricultural fields.

Keywords: Biochar; N fertilizer; N use efficiency; Paddy; Upland.