Methane and nitrous oxide emissions from rice paddy soil as influenced by timing of application of hydroquinone and dicyandiamide

Abstract

A pot trial and a field experiment were conducted to study the effect of timing of application of nitrification inhibitor dicyandiamide (DCD) on N 2 O and CH 4 emissions from rice paddy soil. Four treatments including Treatment CK 1 , DCD-1 (application of DCD with basal fertilizer), DCD-2 (DCD with tillering fertilizer) and DCD-3 (DCD with panicle initiation fertilizer), were designed and implemented in pot experiment. Total N 2 O and CH 4 emissions from DCD-treated soils were decreased profoundly when compared with that from urea alone (P \ 0.05). Application of DCD together with basal fertilizer, tillering fertilizer and panicle initiation fertilizer reduced N 2 O emission by 8, 30 and 2%, respectively, while those for CH 4 were 21, 8 and 1%. The field experiment with four treatments was carried out subsequently, and a kind of urease inhibitor hydroquinone (HQ) was also incorporated with DCD simultaneously. The combined use of HQ and DCD with basal fertilizer, tillering fertilizer and panicle initiation fertilizer decreased N 2 O emissions by 24, 56 and 17%, respectively, while those for CH 4 were 35, 19 and 12%. N 2 O emission was effectively reduced by the inhibitor(s) applied with tillering fertilizer before midseason aeration, while CH 4 emission was effectively decreased by the combined use of inhibitor(s) with basal fertilizer before rice transplanting. Furthermore, an increase in rice yield and a reduction of total global warming potential (GWP) of CH 4 and N 2 O could be achieved by using inhibitor(s) in rice paddy field.

Greenhouse gas emissions during the seedling stage of rice agriculture as affected by cultivar type and crop density

“…The average cumulative CH 4 emission during the ricegrowing season using similar management practices to those of this study was 74.5 kg C ha −1 and ranged from 30.0 kg C ha −1 to 206.6 kg C ha −1 Dong et al 2011;Li et al 2009;Ma et al 2009;Xie et al 2010;Zhang et al 2010;Zou et al 2005a,b;Zou et al 2009). By considering the conventional sowing density, the cumulative CH 4 emissions of this study averaged to 95.0 kg C ha −1 over the rice seedling stage (Table 2), which is comparable with the average estimate for the entire rice-growing season (P>0.05).…”

“…However, the seedling stage N 2 O emissions were comparable to those (0.50-0.62 kg N ha −1 ) of the rice-growing season with midseason drainage Zhao et al 2009) and those (0.12 kg N ha −1 ) under continuous waterlogging . The average annual cumulative N 2 O emissions with similar management practices were calculated to be 3.2 kg N ha − 1 and ranged from 0.50 to 11.29 kg N ha −1 Cao et al 1999;Chen et al 2005Chen et al , 2007Li et al 2009;Liu et al 2010;Ma et al 2009;Xu et al 1997;Zhang et al 2010;Zhao et al 2009;Zou et al 2005a, b;Zou et al 2009). The cumulative N 2 O emissions ranged from 0.07 to 0.62 kg N ha −1 over the rice seedling stage in this study and these values were significantly (P<0.05) lower than the cumulative average emission for the entire rice-growing season ( Table 2).…”

Nitrification inhibitors mitigate earthworm-induced N2O emission—a mesocosm study

“…Therefore, we concluded that N 2 O emissions from mesocosms with earthworms (E. fetida) were mitigated by NI application. Our results confirm that the application of NI can enhance N fertilizer efficiency, by decreasing N 2 O emission from soil, which may mean that the agriculture use of NI is likely to increase in the future (Fettweis et al 2001;Boeckx et al 2005;Li et al 2009;Merino et al 2001). However, only one species of earthworm (E. fetida) was applied in this study, and future research is needed to confirm these results under field conditions and with different species of earthworms.…”

“…arable land and grassland, by inhibiting the nitrifying activities of ammonia-oxidizing bacteria in soil (Fettweis et al 2001;Boeckx et al 2005;Li et al 2009). Dicyandiamide (DCD) reduced N 2 O emissions from maize soil by 37 % (Zaman et al 2008) and that 3,4-dimethylpyrazole phosphate (DMPP) reduced N 2 O emissions by 49 % (Azam et al 2001).…”

Impact of dicyandiamide on emissions of nitrous oxide, nitric oxide and ammonia from agricultural field in the North China Plain

“…It has been well in the nitrification process (Kelliher et al, 2008). DCD has been shown to effectively reduce N 2 O emissions from pasture (Zaman et al, 2008;Cameron et al, 2014;Robinson et al, 2014), grassland (Di and Cameron, 2003;Di et al, 2010), paddy fields (Kumar et al, 2000;Li et al, 2009) and upland soil (Majumdar et al, 2002;Vallejo et al, 2005;Meijide et al, 2007). Both NO and N 2 O are important byproducts of nitrification; however, only few studies (Vallejo et al, 2005;Meijide et al, 2007) have investigated the reduction effect of DCD for both N 2 O and NO from agricultural fields.…”