Priming effect of the addition of maize to a Japanese volcanic ash soil and its temperature sensitivity: a short-term incubation study

• Published in: Soil science and plant nutrition (Tokyo) Vol. 65; no. 5; pp. 444 - 450
• Main Authors: Iimura, Yasuo, Tabara, Issei, Izumitsu, Kosuke, Fujitake, Nobuhide
• Format: Journal Article
• Language: English
• Published: Kyoto Taylor & Francis 03.09.2019; Taylor & Francis Ltd
• Subjects: C4 plants; Carbon dioxide; Carbon dioxide emissions; Climate change; Corn; Emissions control; Global warming; greenhouse gas emissions; labile carbon; leaves; microbial biomass; Microorganisms; Mineralization; Organic matter; Priming; priming effect; Sensitivity analysis; Soil organic matter; Soil temperature; Soils; SOM; stable isotopes; Substrates; Temperature; temperature sensitivity; Volcanic ash; Volcanic ash soil; volcanic ash soils; Volcanic soils; Zea mays
• ISSN: 0038-0768; 1747-0765; 1747-0765
• DOI: 10.1080/00380768.2019.1665969

The response of soil organic matter (SOM) to global warming is a crucial subject. However, the temperature sensitivity of SOM turnover remains largely uncertain. Changes in the mineralization of native SOM, i.e., priming effect (PE) may strongly affect the temperature sensitivity of SOM turnover in the presence of global warming. We investigated the direction and magnitude of the PE in a Japanese volcanic ash soil at different temperatures (15°C, 25°C, and 35°C) using a natural 13 C tracer (C4-plant, maize leaf) in a short-term (25 days) incubation study. In addition, we evaluated the temperature sensitivity expressed as Q 10 value with and without the addition of maize to the soil and their relations to PE. We found that positive PE occurred at each temperature condition and tended to increase with decreased temperature, and these PE results were consistent with the microbial biomass at the end of the incubation period. CO 2 emission from control soil (without maize) increased with increasing temperature (Q 10 = 2.6), but CO 2 emission from the soil with added maize did not significantly change with increasing temperature (Q 10 = 1.0). This was caused by the suppression of CO 2 emission from the soil with increasing temperature (Q 10 = 0.9). On the other hand, soil-originated CO 2 emission clearly increased with increasing temperature (Q 10 = 3.4) when Q 10 values were calculated on the assumption that the temperature and substrate supply increase at the same time (from 25°C). These results suggest that not only the temperature increase but also the labile carbon supply may be important for the temperature sensitivity of Japanese volcanic ash soil.