TY - JOUR
T1 - Long-term effects of gasification biochar application on soil functions in a Mediterranean agroecosystem
T2 - Higher addition rates sequester more carbon but pose a risk to soil faunal communities
AU - Llovet, Alba
AU - Mattana, Stefania
AU - Chin-Pampillo, Juan
AU - Gascó, Gabriel
AU - Sánchez, Sara
AU - Mondini, Claudio
AU - Briones, María Jesús Iglesias
AU - Márquez, Laura
AU - Alcañiz, Josep Maria
AU - Ribas, Angela
AU - Domene, Xavier
N1 - Copyright © 2021 Elsevier B.V. All rights reserved.
PY - 2021/12/20
Y1 - 2021/12/20
N2 - Biochar applications can have important implications for many of the soil functions upon which agroecosystems rely, particularly regarding organic carbon storage. This study evaluated the impacts of adding a highly aromatic gasification biochar at different rates (0, 12 and 50 t ha-1) to a barley crop on the provision of crucial soil functions (carbon sequestration, water content, greenhouse gas emissions, nutrient cycling, soil food web functioning, and food production). After natural ageing in the field for six years, a wide range of soil properties representative of the studied soil functions were measured and integrated into a soil quality index. Results showed that C sequestration increased with biochar rate (23 and 68% higher than in the control for the 12 and 50 t biochar ha-1 treatments, respectively). Water content was enhanced at the 50 t ha-1 treatment depending on the sampling date. Despite biochar additions neither abating nor increasing CO2 equivalent emissions (carbon dioxide plus nitrous oxide and methane), the system shifted from being a methane sink (-0.017 ± 0.01 mg CH4-C m-2 h-1 at the 12 t ha-1 treatment), to a net source (0.025 ± 0.02 mg CH4-C m-2 h-1 at the 50 t ha-1 treatment). In addition, biochar ageing provoked a loss of nitrate mitigation potential, and indeed ammonium production was stimulated at the 50 t ha-1 rate. The 50 t ha-1 treatment also adversely affected nematode and collembolan functional diversity. Lastly, biochar did not affect barley yield. The results of the soil quality index indicated that no biochar treatment provided more benefits to our agricultural soil, and, although the 50 t ha-1 treatment increased C sequestration, this was potentially offset by its harmful effects on soil faunal communities. Therefore, application of this biochar at high rates should be avoided to prevent risks to soil biological communities.
AB - Biochar applications can have important implications for many of the soil functions upon which agroecosystems rely, particularly regarding organic carbon storage. This study evaluated the impacts of adding a highly aromatic gasification biochar at different rates (0, 12 and 50 t ha-1) to a barley crop on the provision of crucial soil functions (carbon sequestration, water content, greenhouse gas emissions, nutrient cycling, soil food web functioning, and food production). After natural ageing in the field for six years, a wide range of soil properties representative of the studied soil functions were measured and integrated into a soil quality index. Results showed that C sequestration increased with biochar rate (23 and 68% higher than in the control for the 12 and 50 t biochar ha-1 treatments, respectively). Water content was enhanced at the 50 t ha-1 treatment depending on the sampling date. Despite biochar additions neither abating nor increasing CO2 equivalent emissions (carbon dioxide plus nitrous oxide and methane), the system shifted from being a methane sink (-0.017 ± 0.01 mg CH4-C m-2 h-1 at the 12 t ha-1 treatment), to a net source (0.025 ± 0.02 mg CH4-C m-2 h-1 at the 50 t ha-1 treatment). In addition, biochar ageing provoked a loss of nitrate mitigation potential, and indeed ammonium production was stimulated at the 50 t ha-1 rate. The 50 t ha-1 treatment also adversely affected nematode and collembolan functional diversity. Lastly, biochar did not affect barley yield. The results of the soil quality index indicated that no biochar treatment provided more benefits to our agricultural soil, and, although the 50 t ha-1 treatment increased C sequestration, this was potentially offset by its harmful effects on soil faunal communities. Therefore, application of this biochar at high rates should be avoided to prevent risks to soil biological communities.
KW - Ageing
KW - Gasification biochar
KW - Greenhouse gas
KW - Nutrient cycling
KW - Soil food web
KW - Soil functions
KW - Carbon Dioxide/analysis
KW - Greenhouse Gases
KW - Methane/analysis
KW - Nitrous Oxide/analysis
KW - Soil
KW - Agriculture
KW - Charcoal
UR - http://www.scopus.com/inward/record.url?scp=85112482386&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.149580
DO - 10.1016/j.scitotenv.2021.149580
M3 - Article
C2 - 34411789
AN - SCOPUS:85112482386
SN - 0048-9697
VL - 801
JO - Science of the total environment
JF - Science of the total environment
M1 - 149580
ER -