Ozone pollution influences soil carbon and nitrogen sequestration and aggregate composition in paddy soils

• Published in: Plant and soil Vol. 380; no. 1/2; pp. 305 - 313
• Main Authors: Kou, Taiji, Wang, Lirui, Zhu, Jianguo, Xie, Zubin, Wang, Yanling
• Format: Journal Article
• Language: English
• Published: Cham Springer 01.07.2014; Springer International Publishing; Springer Nature B.V
• Subjects: Aggregates; Agricultural soils; Agrology; Agronomy. Soil science and plant productions; Air pollution; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Carbon content; Carbon cycle; Cell aggregates; China; chronic exposure; Clay; Clay soils; Ecology; elevated atmospheric gases; Environmental aspects; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Life Sciences; Nitrogen; Nitrogen content; Organic soils; Oryza sativa; Ozone; paddy soils; Physical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant growth; Plant Physiology; Plant Sciences; pollution; Regular Article; Rice; Rice fields; Silt; Soil aggregates; Soil aggregation; Soil chemistry; soil organic carbon; Soil organic matter; Soil pollution; Soil quality; Soil research; Soil science; Soil Science & Conservation; Soil sciences; Soil structure; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Structure, texture, density, mechanical behavior. Heat and gas exchanges; Terrestrial ecosystems; Triticum aestivum; Wheat; China; China, People's Rep., Jiangsu Prov; Free-air ozone enrichment (O; Carbon cycle; Soil aggregate; FACE; Environment change; Ozone pollution; Monocotyledones; Cultivated soil; Property of soil; Environmental factor; Ozone; Soil structure; Stimulating environment; Physical properties; Carbon sequestration; Pollution; Nitrogen cycle; Oryza; Gramineae; Angiospermae; Spermatophyta; Paddy field; Aggregate; Soil plant relation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-014-2096-7

Background and aims Much attention has focused on the effects of tropospheric ozone (O₃) on terrestrial ecosystems and plant growth. Since O₃ pollution is currently an issue in China and many parts of the world, understanding the effects of elevated O₃ on soil carbon (C) and nitrogen (N) sequestration is essential for efforts to predict C and N cycles in terrestrial ecosystems under predicted increases in O₃. Thus the main objective of this study was to determine whether an increases in atmospheric O₃ concentration influenced soil organic C (SOC) and N sequestration. Methods A free-air O₃ enrichment (O₃-FACE) experiment was started in 2007 and used continuous O₃ exposure from March to November each year during crop growth stage in a rice (Oryza sativa L.)—wheat (Triticum aestivum L.) rotation field in the Jiangsu Province, China. We investigated differences in SOC and N and soil aggregate composition in both elevated and ambient O₃ conditions. Results Elevated atmospheric O₃ (18-80 nmol mol⁻¹ or 50% above the ambient) decreased the SOC and N concentration in the 0-20 cm soil layer after 5 years. Elevated O₃ significantly decreased the SOC concentration by 17% and 5.6% in the 0-3 cm and the 10-20 cm layers, respectively. Elevated O₃ significantly decreased the N concentration by 8.2-27.8% in three layers at the 20 cm depth. In addition, elevated O₃ influenced the formation and transformation of soil aggregates and the distribution of SOC and N in the aggregates across soil layer classes. Elevated O₃ significantly decreased the macro-sized aggregate fraction (16.8%) and associated C and N (0.5 g kg⁻¹ and 0.32 g kg⁻¹, respectively), and significantly increased the silt+clay-sized aggregate fraction (61%) and associated C (1.7 g kg⁻¹) in the 0-3 cm layer. Elevated O₃ significantly decreased the macro-sized aggregate fraction (9.6%) and associated C and N (1.4 g kg⁻¹ and 0.35 g kg⁻¹, respectively), and significantly increased the silt+clay-sized aggregate fraction (41.8%) and decreased the corresponding associated N (0.14 g kg⁻¹) in the 3-10 cm layer. Elevated O₃ did not significantly effect the formation and transformation of aggregates in the 10-20 cm layer, yet it did significantly increase the C concentration in the macro-sized fraction (1 g kg⁻¹) and decrease the N concentration in the macro-and micro-sized fractions (0.24 g kg⁻¹ and 0.16 g kg⁻¹, respectively). Conclusion Long-term exposure to elevated atmospheric O 3 negatively affected the physical structure of the soil and impaired soil C and N sequestration.