Estimation of soil microbial biomass as the sink and source of base cation nutrients

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K07337
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant nutrition/Soil science
• Research Institution: Nagoya University
• Principal Investigator: Asakawa Susumu 名古屋大学, 生命農学研究科, 教授 (50335014)
• Research Collaborator: YAMASHITA Kohei ; TOKONAMI Yoshiki
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 土壌微生物バイオマス / 塩基類養分

Outline of Final Research Achievements

This research project focused on soil microbial biomass as the sink and source of base cation nutrients for crops. The aim of this project was to reveal the functions of soil microbial biomass quantitatively by estimating amounts of base cations in soluble, exchangeable and biomass fractions and flow of the cations from the biomass fraction to the soluble and exchangeable fractions in soil. Amounts of biomass potassium and their dynamics were estimated in various farmland soils such as in rice paddy, upland, grassland and orchard soils. The conversion factors for estimation of biomass potassium by the chloroform-fumigation extraction method were presented in the paddy and upland soils. In addition, a turnover time of biomass potassium was calculated for the first time.

Free Research Field

土壌微生物学

Academic Significance and Societal Importance of the Research Achievements

土壌中の微生物バイオマスに貯蔵されているカリウム量は，これまで植物へのカリウムの主要な供給源と考えられていた粘土鉱物などに保持されている交換性カリウム量の約3割に相当することや、微生物バイオマス中のカリウムが活発に代謝回転していることを明らかにし，カリウムの貯蔵源・供給源としての土壌微生物バイオマスの重要性を示した。