open access

https://hdl.handle.net/2115/86660

Factors impacting soil organic carbon pool in different types of Andosols in Toya, Hokkaido, Japan

英語

soil texture

2021-09-03

Taylor & Francis

Soil science and plant nutrition

67(5)

594-605

Organic matter (OM) application is a possible solution to carbon (C) sequestration. Among the soil pedogenic factors for volcanic ash, time of exposure to weathering affects formation of short-range ordered minerals and soil organic carbon (SOC) accumulation. This study aimed to evaluate the effect of long-term OM application with the vertical infiltration of OM on different ages of Andosols in Hokkaido, Japan. Twelve fields of Vitric Andosols and 22 fields of Silandic Andosols were selected. Vitric and Silandic Andosols are characterized by newly erupted volcanic ash with weak weathering, and formation of short-range ordered minerals by weathering, respectively. The C application rate via OM was determined using questionnaires given to farmers, and soil physicochemical properties in the 0-0.15 m and 0.15-0.30 m layers were analyzed. The average C application rate in Vitric and Silandic Andosols were 1.71 +/- 1.18 and 1.31 +/- 1.28 (Mg C ha(-1) yr(-1)), respectively (mean +/- sd). The sand content was significantly higher in Vitric Andosols (55.7% +/- 4.0%) than in Silandic Andosol (51.2% +/- 2.0%). Although there was no significant difference in micro-porosity, Silandic Andosols had significantly higher total porosity and lower bulk density than Vitric Andosols. These results indicate better soil structure development in Silandic Andosols. The SOC stock in the 0-0.30 m layer in Vitric Andosols [71.5 +/- 15.3 (Mg C ha(-1) 0.30 m(-1))] was significantly lower than in Silandic Andosols [86.4 +/- 12.7 (Mg C ha(-1) 0.30 m(-1))]. The SOC stock in Vitric and Silandic Andosols showed a different response to the OM application. An increased C application rate significantly increased the SOC stock in the 0-0.15 and 0-0.30 m layers in Vitric Andosols, but the relations were not significant in Silandic Andosols. In contrast, in Silandic Adosols, weak trends (p = 0.07) were observed in the 0.15-0.30 m layer. In Silandic Andosols, SOC stock in the 0-0.15 m layer showed a z significant positive correlation with soil micro-porosity, suggesting physical protection of OM inside the aggregate. These results suggest that there are different factors affecting SOC stock between Vitric and Silandic Andosols.

学術雑誌論文

Accepted Manuscript

This is an Accepted Manuscript of an article published by Taylor & Francis in Soil science and plant nutrition on 11 Aug 2021, available online: http://www.tandfonline.com/10.1080/00380768.2021.1959836

0038-0768