Examination of the forms of soil phosphorus in relation to soil formation factor

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660051
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Plant nutrition/Soil science
• Research Institution: National Institute for Agro-Environmental Sciences
• Principal Investigator: Wagai Rota 国立研究開発法人 農業環境技術研究所, その他部局等, 上級研究員 (80456748)
• Co-Investigator(Kenkyū-buntansha): HASHIMOTO Yohei 東京農工大学, 生物システム応用科学府, 准教授 (80436899)
• Co-Investigator(Renkei-kenkyūsha): HIRADATE Shuntaro 農業環境技術研究所, 生物多様性研究領域, 上席研究員 (60354099)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: リン / 物質循環 / 熱帯林 / 土壌化学

Outline of Final Research Achievements

Phosphorus (P) is one of the most common limiting nutrients for plants. Better understanding on the amounts and chemical forms of soil P as well as controlling factors behind them is critical. Using 31P-NMR and other chemical techniques, we studied a series of soils developed on two contrasting parent materials along an elevation gradient from 700 to 3100 m on the slope of Mt. Kinabalu, Borneo. At the lowest elevation sites where soil is most chemically weathered and decomposition is most rapid, we found that inorganic P (phosphate) sorbed onto soil minerals is the major form. At higher elevation sites where microbial decomposition of organic matter is slower due to cooler climate and lower litter quality, organic forms of P (mono-ester > di-ester) became more dominant. We also found that polyphosphate tended to be greater in proportion in Fe-rich ultrabasic soils compared to sedimentary soils.

Free Research Field

土壌学、生物地球化学