Linking dissolved organic carbon cycling to organic carbon fluxes in rice paddies under different water management practices

Transformation of beech forest litter as a factor that triggers arsenic solubility in soils developed on historical mine dumps

“…Such changes were confirmed in case of two ZS soils by a decrease of A4:A6 index as well as by increase of SUVA 254 after 14 or 28 days of incubation. Similar changes in SUVA were described by Said-Pullicino et al (2016) in submerged soils. The litterderived compounds as well as, most probably, some soilderived substances released in the long term into the pore water have probably a potential to bind arsenates and to be, as such complexes, sorbed onto soil solid phase, contributing in that way to As removal from soil solution.…”

Water Management Options for Rice Cultivation in a Temperate Area: A Multi-Objective Model to Explore Economic and Water Saving Results

“…Notwithstanding, performing water saving techniques in rice-cultivation is a strategy that enables increasing water resource availability for augmented irrigated farmland, mitigates the effects of climate change or prevents them thanks to reduced greenhouse gasses emissions [45,58]. As a further environmental concern, submerged paddy fields and their long-term maintenance have created not only traditional local landscapes, but also agro-environmental habitats with peculiar ecosystem services.…”

Early season N<sub>2</sub>O emissions under variable water management in rice systems: source-partitioning emissions using isotope ratios along a depth profile

“…In the WS treatments we observed a minimized trend of N 2 O reduction compared to the DS-AWD treatment, more scattered high SP values and more values intermediate to the two end-member pools. These results may partially be explained by greater contributions from abiotic hydroxylamine decomposition (SP ∼ 34 ‰-35 ‰; Heil et al, 2014) or fungal denitrification (SP ∼ 35 ‰; Rohe et al, 2014). Zhou et al (2001) showed that fungal denitrification requires minimal oxygen to proceed; similarly Seo and De-Laune (2010) found that fungal denitrification dominated relative to bacterial denitrification at modest reducing conditions to weakly oxidizing conditions (Eh > 250 mV).…”

“…Our SP end-member values (SP den and SP nit ) and N 2 O reduction fractionation factors (ε 18 O red and εSP red ) were taken directly from Lewicka-Szczebak et al (2017) ( Table 2). For 2017; this yielded a mean of 36.5 ‰ (Heil et al, 2014;Sutka et al, 2006Sutka et al, , 2008Frame and Casciotti, 2010;Rohe et al, 2014;Maeda et al, 2015). For δ 18 O-N 2 O den we adjusted the value used in by an estimate of δ 18 O-H 2 O of water for our site rather than recalculating it from the four studies originally referenced by Frame and Casciotti, 2010;Sutka et al, 2006).…”

“…In improving the NUE, a better estimate of N 2 O reduction to N 2 is needed to design strategies that reduce N 2 losses without increasing N 2 O emission. N 2 O is predominately produced (1) as a byproduct during nitrification, where NH + 4 is oxidized to NO − 3 via hydroxylamine (NH 2 OH) (this step of nitrification is sometimes referred to as hydroxylamine oxidation; Schreiber et al, 2012;Hu et al, 2015), or (2) as an intermediate in the denitrification pathway during which NO − 3 is reduced to N 2 (Firestone et al, 1989) or (3) during nitrifier denitrification by specific ammonia-oxidizing bacteria that oxidize NH + 4 to NH 2 OH and then to NO − 2 , with a small fraction of NO − 2 then being reduced to NO and N 2 O (Kool et al, 2010(Kool et al, , 2011Wrage et al, 2001). N 2 O may also be produced from additional biotic and abiotic processes, such as fungal denitrification, coupled nitrification-denitrification, dissimilatory nitrate reduction to ammonium, chemodenitrification or hydroxylamine decomposition (Butterbach-Bahl et al, 2013;Heil et al, 2015;Zhu-Barker et al, 2015).…”