Hydrochar did not reduce rice paddy NH3 volatilization compared to pyrochar in a soil column experiment

• Published in: Scientific reports Vol. 10; no. 1; p. 19115
• Main Authors: Liu, Xiaoyu, Cheng, Yueqin, Liu, Yang, Chen, Danyan, Chen, Yin, Wang, Yueman
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.11.2020; Nature Publishing Group
• Subjects: 704/158/2445; 704/158/2456; Aging; Agriculture; Ammonia; Biomass; Charcoal; Chemical oxygen demand; Crop production; Experiments; Fertilizers; Humanities and Social Sciences; Laboratories; multidisciplinary; Nitrogen; pH effects; Raw materials; Rice; Rice fields; Sawdust; Science; Science (multidisciplinary); Soil columns; Volatilization; Wheat straw
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-76213-z

Pyrochar (PC) is always with high pH value, and improper application might increase rice paddy ammonia volatilization (PAV), which is the main nitrogen loss through air during rice production. Differently, hydrochar (HC) takes the advantages of high productive rate and always with lower pH value compared with PC. However, effect pattern and mechanism of HC on PAV are still unclear. In the present study, soil column experiments were conducted to investigate the effect of PC and HC application on PAV. In total, treatments with four types of biochar (WPC, SPC, WHC and SHC, i.e., PC and HC prepared with wheat straw and sawdust, respectively) and two application rates (0.5% and 1.5%, w/w) were set up and non-biochar application was used as control. Results showed that, application of HC with low pH value could not reduce PAV compared with PC. Total PAV increased significantly as the increase of HC application rate (especially for WHC). The increment of PAV under high rate HC application might be due to the strong buffer capacity of soil, the aging of biochar, the high nitrogen from HC. The results indicated that HC should be pretreatment before utilization in agricultural environment considering PAV reduction.