Details
| Original language | English |
|---|---|
| Pages (from-to) | 35-47 |
| Number of pages | 13 |
| Journal | BIOGEOCHEMISTRY |
| Volume | 160 |
| Issue number | 1 |
| Early online date | 14 May 2022 |
| Publication status | Published - Aug 2022 |
Abstract
Phytolith is widely known as a silica structure in numerous silicon (Si) accumulator plants, e.g., rice, and it contains various nutrients and other beneficial elements. When rice straw is returned to paddy fields, the silica structure of phytolith can be dissolved, thereby releasing its occluded nutrients. While the intrinsic characteristics and dissolution properties of phytoliths under the effect of solution chemistry have been intensively studied, the effect of gas phases, especially CO2, on phytolith stability and the implications for nutrient release are not fully known. Here, dissolution properties of phytolith ashes obtained from dry ashing of rice straw at 400, 600 and 800 °C were investigated by quantifying Si release together with other nutrients under two atmospheric conditions, i.e., without and with CO2 support (aeration). In a time span of 6 days, the releases of nutrients (K, P, Ca, Mg) showed high dependence on the overall dissolution of the phytolith ashes. CO2 significantly reduced the dissolution rate of the phytolith ashes but increased the release rates of cationic as well as anionic nutrients. The aeration of CO2 shifted the carbonate equilibrium (H2CO3, HCO3− and CO32−) towards H2CO3, reducing solution pH, thereby decreasing the dissolution rate of phytoliths. Following this, intensification of H+ exchange promoted nutrient releases from the phytolith ashes. This indicates contrasted responses of phytoliths and their occluded nutrients to CO2, and provides a better insight on the fate of soil phytoliths and the tendency of nutrient budgets from rice straw phytoliths in soils.
Keywords
- Ashes, CO effects, Nutrient release, Phytolith, Rice straw
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Environmental Science(all)
- Water Science and Technology
- Earth and Planetary Sciences(all)
- Earth-Surface Processes
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In: BIOGEOCHEMISTRY, Vol. 160, No. 1, 08.2022, p. 35-47.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - The regulatory role of CO2 on nutrient releases from ashed rice straw phytoliths
AU - Nguyen, Anh T.Q.
AU - Nguyen, Anh M.
AU - Nguyen, Muu T.
AU - Nguyen, Hue T.
AU - Duong, Lim T.
AU - Dinh, Van M.
AU - Nguyen, Phuong M.
AU - Dultz, Stefan
AU - Nguyen, Minh N.
PY - 2022/8
Y1 - 2022/8
N2 - Phytolith is widely known as a silica structure in numerous silicon (Si) accumulator plants, e.g., rice, and it contains various nutrients and other beneficial elements. When rice straw is returned to paddy fields, the silica structure of phytolith can be dissolved, thereby releasing its occluded nutrients. While the intrinsic characteristics and dissolution properties of phytoliths under the effect of solution chemistry have been intensively studied, the effect of gas phases, especially CO2, on phytolith stability and the implications for nutrient release are not fully known. Here, dissolution properties of phytolith ashes obtained from dry ashing of rice straw at 400, 600 and 800 °C were investigated by quantifying Si release together with other nutrients under two atmospheric conditions, i.e., without and with CO2 support (aeration). In a time span of 6 days, the releases of nutrients (K, P, Ca, Mg) showed high dependence on the overall dissolution of the phytolith ashes. CO2 significantly reduced the dissolution rate of the phytolith ashes but increased the release rates of cationic as well as anionic nutrients. The aeration of CO2 shifted the carbonate equilibrium (H2CO3, HCO3− and CO32−) towards H2CO3, reducing solution pH, thereby decreasing the dissolution rate of phytoliths. Following this, intensification of H+ exchange promoted nutrient releases from the phytolith ashes. This indicates contrasted responses of phytoliths and their occluded nutrients to CO2, and provides a better insight on the fate of soil phytoliths and the tendency of nutrient budgets from rice straw phytoliths in soils.
AB - Phytolith is widely known as a silica structure in numerous silicon (Si) accumulator plants, e.g., rice, and it contains various nutrients and other beneficial elements. When rice straw is returned to paddy fields, the silica structure of phytolith can be dissolved, thereby releasing its occluded nutrients. While the intrinsic characteristics and dissolution properties of phytoliths under the effect of solution chemistry have been intensively studied, the effect of gas phases, especially CO2, on phytolith stability and the implications for nutrient release are not fully known. Here, dissolution properties of phytolith ashes obtained from dry ashing of rice straw at 400, 600 and 800 °C were investigated by quantifying Si release together with other nutrients under two atmospheric conditions, i.e., without and with CO2 support (aeration). In a time span of 6 days, the releases of nutrients (K, P, Ca, Mg) showed high dependence on the overall dissolution of the phytolith ashes. CO2 significantly reduced the dissolution rate of the phytolith ashes but increased the release rates of cationic as well as anionic nutrients. The aeration of CO2 shifted the carbonate equilibrium (H2CO3, HCO3− and CO32−) towards H2CO3, reducing solution pH, thereby decreasing the dissolution rate of phytoliths. Following this, intensification of H+ exchange promoted nutrient releases from the phytolith ashes. This indicates contrasted responses of phytoliths and their occluded nutrients to CO2, and provides a better insight on the fate of soil phytoliths and the tendency of nutrient budgets from rice straw phytoliths in soils.
KW - Ashes
KW - CO effects
KW - Nutrient release
KW - Phytolith
KW - Rice straw
UR - http://www.scopus.com/inward/record.url?scp=85130113739&partnerID=8YFLogxK
U2 - 10.1007/s10533-022-00938-4
DO - 10.1007/s10533-022-00938-4
M3 - Article
AN - SCOPUS:85130113739
VL - 160
SP - 35
EP - 47
JO - BIOGEOCHEMISTRY
JF - BIOGEOCHEMISTRY
SN - 0168-2563
IS - 1
ER -