The six-year biochar retention interacted with fertilizer addition alters the soil organic nitrogen supply capacity in bulk and rhizosphere soil

Di Wang; Yu Lan; Wenfu Chen; Xiaori Han; Suying Liu; Dianyun Cao; Xiaoyi Cheng; Qingyang Wang; Zengyi Zhan; Wanying He

doi:10.1016/j.jenvman.2023.117757

The six-year biochar retention interacted with fertilizer addition alters the soil organic nitrogen supply capacity in bulk and rhizosphere soil

J Environ Manage. 2023 Jul 15:338:117757. doi: 10.1016/j.jenvman.2023.117757. Epub 2023 Mar 28.

Authors

Di Wang¹, Yu Lan², Wenfu Chen³, Xiaori Han⁴, Suying Liu¹, Dianyun Cao¹, Xiaoyi Cheng¹, Qingyang Wang¹, Zengyi Zhan¹, Wanying He¹

Affiliations

¹ Agronomy College, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, PR China, Shenyang, 110866, China.
² Agronomy College, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, PR China, Shenyang, 110866, China. Electronic address: lanyu312228@syau.edu.cn.
³ Agronomy College, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, PR China, Shenyang, 110866, China. Electronic address: 1979500003@syau.edu.cn.
⁴ Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, PR China, Shenyang, 110866, China; Land and Environment College, Shenyang Agricultural University, Shenyang, 110866, China.

PMID: 36996567
DOI: 10.1016/j.jenvman.2023.117757

Abstract

Nitrogen fractions in soil, like organic nitrogen, mineral nitrogen, and free amino acids, are sensitive pointers to the soil nitrogen pools involved in nutrient cycling. As a potential improvement measure, biochar might improve soil fertility and nutrient availability. However, few studies have focused on the long-term effects of biochar retention on the soil nitrogen supply capacity of bulk and rhizosphere soil in brown earth. Therefore, a six-year field experiment was conducted in 2013, concentrating on the impact of biochar retention on soil nitrogen fractions. Four biochar rates were tested: no biochar amendment (CK); 15.75 t ha^-1 of biochar (BC1); 31.5 t ha^-1 of biochar (BC2); 47.25 t ha^-1 of biochar (BC3). Our results showed that the elevated application rates significantly enhanced soil organic matter (SOM), and total nitrogen (TN), and improved pH in both bulk and rhizosphere soils. Acid-hydrolyzable nitrogen (AHN) content in biochar treatments was higher than that of CK in bulk and rhizosphere soil. The content of non-hydrolyzable nitrogen (NHN) was increased in 47.25 t ha^-1 of biochar retention. Ammonium nitrogen (AN) and amino sugar nitrogen (ASN) contents were higher in bulk soil than in rhizosphere soil. Neutral amino acid contents were the highest both in bulk and rhizosphere soil. Principal component analysis (PCA) showed that soil organic nitrogen was significantly influenced by BC3 treatment in bulk soil, and largely influenced by other treatments in rhizosphere soil. Partial least square path modeling (PLSPM) revealed that NH₄⁺-N was mainly derived from amino acid nitrogen (AAN) and AN in bulk soil and AAN and ASN in rhizosphere soil. These results indicate that different biochar retention rates contributed to improve soil nutrients. Amino acid nitrogen was the prominent nitrogen source of NH₄⁺-N in bulk and rhizosphere soils.

Keywords: Biochar retention; Free amino acid; Long-term location experiment; Rhizosphere; Soil organic nitrogen fractions.

MeSH terms

Amino Acids
Charcoal
Fertilizers / analysis
Nitrogen / analysis
Rhizosphere*
Soil* / chemistry

Substances

Soil
Fertilizers
Nitrogen
biochar
Charcoal
Amino Acids