@article{fdi:010072457,
  title = {{O}rigin of silica in rice plants and contribution of diatom {E}arth fertilization : insights from isotopic {S}i mass balance in a paddy field},
  author = {{R}iotte, {J}ean and {S}andhya, {K}. and {P}rakash, {N}. {B}. and {A}udry, {S}. and {Z}ambardi, {T}. and {C}hmeleff, {J}. and {B}uvaneshwari, {S}. and {M}eunier, {J}. {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he benefits of {S}i for crops is well evidenced but the biogeochemical cycle of {S}i in agriculture remains poorly documented. {T}his study aims at identifying and quantifying the {S}i sources (primary and secondary soil minerals, amorphous silica, irrigation, {S}i-fertilizer) to rice plants. {F}ield experiments were carried out with and without application of diatomaceous earth ({DE}) under rice and bare conditions to determine the water and dissolved mass balance in paddy fields ({K}arnataka, {S}outhern {I}ndia). {T}he fate of the {S}i brought by irrigation ({DS}i) (uptake by rice, uptake by diatoms, adsorption) was assessed through a solute mass balance combined with silicon isotopic signatures. {A}bove the ground-surface, about one third of the {DS}i flux brought by borewell irrigation (545 mmol {S}i.m(-2)) to bare plots and half of {DS}i in rice plots were removed from solution within minutes or hours following irrigation. {S}uch rate is consistent with the rate of {DS}i adsorption onto {F}e-oxyhydroxides but not with diatom blooms. {I}n rice and rice + {DE} experiments, the isotopic fractionation factor ((30)epsilon) between bore well and stagnant water compositions is close to -1 a{E}uro degrees, i.e. the isotopic fractionation factor known for rice, indicating that above-ground {DS}i removal would be dominated by plant uptake upon adsorption. {W}ithin the soil layer, pore water {DS}i decreases much faster in rice experiments than in bare ones, demonstrating the efficiency of {DS}i rice uptake upon adsorption. {T}otal irrigation-{DS}i to plant-{S}i would then represent 24 to 36% in rice experiments (over 1460 +/- 270 mmol {S}i m(-2) in biomass) and 15 to 23% in rice + {DE} ones (over 2250 +/- 180 mmol {S}i m(-2)). {T}he delta {S}i-30 signature of whole plants was significantly different in the rice + {DE} plot analyzed, 0.99 +/- 0.07 a{E}uro degrees, than in the rice one, 1.29 +/- 0.07 a{E}uro degrees. {A}ccording to these delta {S}i-30 signatures, the main {S}i source from the soil would be the amorphous silica pool ({AS}i). {A} slight contribution of {DE} to the rice plant could be detected from the {S}i isotopic signature of rice. {T}he delta {S}i-30 signatures of the various soil-plant compartments, when associated to {S}i mass balance at soil-plant scale, constitute a reliable proxy of the {S}i sources in paddy fields. {T}he solute {S}i balance is controlled by rice uptake in rice plots and by adsorption in bare ones. {T}he main {S}i sources for the rice plants were soil {AS}i, irrigation {S}i and to a lesser extent {S}i fertilizer when it was applied.},
  keywords = {{R}ice ; {S}ilicon isotopes ; {N}utrients ; {S}ilica mass balance ; {P}lant uptake ; {T}ropics ; {S}outh {I}ndia ; {INDE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{P}lant and {S}oil},
  volume = {423},
  numero = {1-2},
  pages = {481--501},
  ISSN = {0032-079{X}},
  year = {2018},
  DOI = {10.1007/s11104-017-3535-z},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072457},
}