Effect of Soil Characteristics and Potassium Application Rate on the Plant–Absorbable Potassium Forms and Transport Mechanisms in Soil

• Mori Yuki

  Laboratory of Environmental Geochemistry, Division of Bioproduction Environmental Sciences, Department of Agro–Environmental Sciences, Faculty of Agriculture, Kyushu University

• Yoshida Minako

  Laboratory of Environmental Geochemistry, Division of Bioproduction Environmental Sciences, Department of Agro–Environmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University

• Wada Shin-ichiro

  Laboratory of Environmental Geochemistry, Division of Bioproduction Environmental Sciences, Department of Agro–Environmental Sciences, Faculty of Agriculture, Kyushu University

Abstract

Although the demand for saving potassium (K) fertilizer application is increasing, the evaluation of available K by exchangeable K that is operationally defined as 1 M ammonium acetate–extractable K has limitations. In order to investigate the contribution of soil K forms and transport mechanisms for K uptake, pot experiment was performed using two soils with varying K application rate. The spinach grown in vermiculite–rich soil absorbed considerable amount of K from nonexchangeable fraction and the transport mechanism was mainly by diffusion, whereas the plant cultivated in volcanic ash soil, which contain less vermiculite, mostly absorbed exchangeable K and the contribution of mass flow was substantially high. Exchangeable K and soil solution K in vermiculite–rich soil did not much increased at the high rate of K application. A part of applied K might become readily absorbable–nonexchangeable K. To evaluate K supplying capacity of soil, it is necessary to quantify not only exchangeable K but also the K fixation and the amount of K released from nonexchangeable sites. In soil whose K fixation capacity is low, the transport of K from soil might be modeled by solute transport and cation exchange.

Journal

• Journal of the Faculty of Agriculture, Kyushu University

  Journal of the Faculty of Agriculture, Kyushu University 57 (2), 485-488, 2012-09-20

  Faculty of Agriculture, Kyushu University

Keywords

• diffusion
• exchangeable K
• mass flow
• nonexchangeable K
• potassium

Details

• CRID: 1390290699660618624
• NII Article ID: 120004756205
• NII Book ID: AA00247166
• DOI: 10.5109/25210
• HANDLE: 2324/25210
• ISSN: 00236152
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles