Portal de Periódicos da CAPES

Measurement of Si adsorption and “Active Si” in a soil amended with slag fertilizers by using stable isotope 30 SP

1997; Taylor & Francis; Volume: 43; Issue: 3 Linguagem: Inglês

10.1080/00380768.1997.10414788

1747-0765

Naoto Kato, Kazuyoshi Yanagisawa, Naoto Owa,

Aluminum toxicity and tolerance in plants and animals

Abstract The silicic acid adsorption by a soil (Eutric Gleysols) where slag fertilizers were applied was measured by the addition of a silicic acid solution labelled with 30Si after soil incubation, in order to study the effect of slag application on the specific Si adsorption by the soil and to estimate the amount of Si in the soil solid phase which can easily enter the soil solution. It was evident that the application of slags increased the ability of soil to adsorb Si. It was also shown that the 30Si added was diluted with not only the Si present in the soil solution but also the Si dissolved from the soil solid phase. We proposed the use of the term "active" for Si in soil which can take part in the isotopic dilution within 1 h. The amount of active Si in the soil solid and liquid phases (D 60 - value) was calculated from the 30Si content in the soil solution and compared with the amount of Si taken up by rice plant (Oryza sativa L.), which was determined in our previous study. The buffering capacity of the soil for Si, which can reflect the ability of soil to maintain the Si concentration in the soil solution constant when Si is added to or removed from the soil, was also determined. The D 60 - value and the Si buffering capacity of the soil increased by slag application. These increases were large when the alkalinity of the applied slags was high. The correlation study revealed that the D 60 - value was a better index of Si availability of the soil than the amount of Si dissolved from the soil solid phase during the incubation when the slags were previously applied. Key Words: adsorptionavailable Siisotopic dilutionsiliconslag A part of this study was reported at the Meeting of the Japanese Society of Soil Science and Plant Nutrition, Matsudo, 1991. A part of this study was reported at the Meeting of the Japanese Society of Soil Science and Plant Nutrition, Matsudo, 1991. Notes A part of this study was reported at the Meeting of the Japanese Society of Soil Science and Plant Nutrition, Matsudo, 1991.