Mitigation of N2O and CH4 Emission from Rice and Wheat Cropping Systems Using Dicyandiamide and Hydroquinone

Abstract

Agriculture contributes considerably to the emission of greenhouse gases, such as N 2 O and CH 4 . Here we summarize results from previous pot experiments assessing the effectiveness of urease and nitrification inhibitors reducing both N 2 O and CH 4 emissions from wheat and rice cropping systems fertilized with urea (U). For the wheat cropping system, using a cambisol, we observed that the application of U with hydroquinone (HQ, a urease inhibitor), U with dicyandiamide (DCD, a nitrification inhibitor) and U with HQ plus DCD decreased the N 2 O emissions by 11.4, 22.3 and 25.1%, respectively. For the rice copping system, using a luvisol, we found that the application of U with HQ, U with DCD and U with HQ plus DCD decreased N 2 O emissions by 10.6, 47.0 and 62.3%, respectively, and CH 4 emissions by 30.1, 53.1 and 58.3%, respectively. In terms of total global warming potential (GWP) a reduction of 61.2% could be realized via the combined addition of HQ and DCD. The addition of wheat straw reduced the activity of HQ and DCD in the rice cropping experiments. In terms of total GWP only a reduction of 30.7% could be achieved. In general, both in upland and flooded conditions, the application of HQ and DCD alone was less effective than HQ in combination with DCD, but not significantly for U plus DCD treatment. Our observations may be further constrained, however, by practical, economic or social problems and should therefore be tested at the scale of a region (e.g. a watershed) and related to an integrated abatement of agricultural N losses.

The combined effects of nitrification inhibitor and biochar incorporation on yield-scaled N<sub>2</sub>O emissions from an intensively managed vegetable field in southeastern China

“…A two-way ANOVA indicated that seasonal N 2 O emissions during the vegetable-growing periods were significantly affected by nitrapyrin application (Table 4, p < 0.001), in agreement with previous results (Ma et al, 2013;Xiong et al, 2013;Zhang et al, 2015). Different types of NI that were effective in reducing N 2 O have been reported by previous studies (Xu et al, 2000;Boeckx et al, 2005;Zaman et al, 2008Zaman et al, , 2009; Zaman and Blenner- DF -degrees of freedom; SS -sum of squares; F -ratio of mean squares of two independent samples; P -index of differences between the control group and the experimental group. If p < 0.05 and p < 0.001, significant differences exists between the control group and the experimental group.…”

A 2-yr field assessment of the effects of chemical and biological nitrification inhibitors on nitrous oxide emissions and nitrogen use efficiency in an intensively managed vegetable cropping system

“…Maintaining a high soil NH 4 + content for a longer time by regulating the rapid conversion of soil N can effectively alleviate NO 3 À accumulation and leaching losses, in addition to reducing N 2 O emissions Fangueiro et al, 2009). Thus, a large number of studies have shown that N fertilizers with NIs are more environmentally friendly (Xu et al, 2000;Boeckx et al, 2005;Zaman et al, 2008Zaman et al, , 2009Zaman and Blennerhassett, 2010;Ding et al, 2011). In the present study, we observed that the application of CP and BNI increased soil NH 4 + content and slightly decreased soil NO 3 À content.…”

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).…”