Integrated assessment of the impact of enhanced-efficiency nitrogen fertilizer on N2O emission and crop yield
Introduction
Synthetic nitrogen (N) fertilizer has played a key role in enhancing crop production to feed 40% of the world’s population since the Haber-Bosch process was invented in the 20th century (Crews and Peoples, 2004). Over the next 40 years, global N fertilizer for crop production is estimated to increase 1.4 fold to meet the projected food demand for 9 billion populations in 2050 (Tilman et al., 2001, Faostat, 2014). However, the increasing use of N fertilizer in crop production has been identified as a main contributor to the rising levels of atmospheric N2O, which is a long-lasting greenhouse gas that significantly contributes to stratospheric ozone depletion and global climate change (Ravishankara et al., 2009). N2O emission is positively correlated with N application rates in linear or nonlinear relationships in agro-ecosystems (Shcherbak et al., 2014). Consequently, any further increase in N fertilizer application to ensure food security might further stimulate N2O emissions (Popp et al., 2010, Van Beek et al., 2010). Therefore, it is essential to mitigate N2O emission by improving N use efficiency (NUE).
Enhanced-efficiency nitrogen fertilizer (EENF) is designed to reduce potential N loss to the environment and to improve N use efficiency (Halvorson et al., 2014). The main EENF products are slow- or control-releasing fertilizer (S/CRF) and normal N sources treated with nitrification inhibitors (NI) and/or urease inhibitors (UI; Dell et al., 2014). Many reviews (Smith et al., 1997, Oenema et al., 2001, Akiyama et al., 2010, Decock, 2014, Halvorson et al., 2014) and IPCC reports (Smith et al., 2007, Smith et al., 2014) have suggested these products as mitigation options for N2O emission from cropland soils. However, increasing evidence from field experiments showed that the performances of EENF were highly variable across studies. Some studies reported that EENF significantly mitigated N2O emissions compared with normal N fertilizer (Halvorson et al., 2010), and others no significant difference (Chu et al., 2007), or even significantly higher N2O emissions (Hu et al., 2013) with EENF. Furthermore, EENF affects both N2O emission and crop yield. The integrated effect of EENF on N2O emission and crop yield is still uncertain. Reduced N2O emission with either significantly increased (Ma et al., 2013), decreased (Asgedom et al., 2014), or unchanged (Halvorson and Del Grosso, 2013) crop yield has been observed in previous studies. These contradictory results indicate the highly complex nature of the effect of EENF on N2O emission and crop yield.
The mechanisms underlying the effects of EENF on N2O emission are mainly through limiting the substrate pools available for the microbial process of N2O production (Malla et al., 2005, Halvorson et al., 2014). For example, S/CRF can reduce the rate of N release to better match crop uptake; while NI delays the oxidation of ammonia (NH4+) to nitrite (NO2−) and then nitrate (NO3−); and UI prevents the transformation of urea to NH4+ (Trenkel, 2010). However, these effects on subsurface processes might be affected by climate, soil properties, or agronomical practices. Soil pH might affect the retention time and the effect of NI (Hendrickson and Keeney, 1979, Xue et al., 2012). Meanwhile, agronomical practices might indirectly affect nutrient release from EENF by changing soil properties. For instance, compared with conventional tillage, no-tillage can increase soil bulk density and moisture (De Vita et al., 2007), which in turn may weaken the effect of S/CRF on delay N release from fertilizer. Furthermore, management practices also directly affect N source competition of N2O production and plant uptake by adjusting fertilizer application rates and timings (Drury et al., 2012). Therefore, a better understanding of the impacts of these factors on the effects of EENF will provide good guidelines for the application of EENF in order to mitigate N2O emission with increased crop yield.
Considering the balance of food security and greenhouse gas mitigation, increasing numbers of studies have proposed that an integrated assessment of yield-scaled N2O emission will be particularly important for these practices such as EENF affected both N2O emission and crop yield (Van Groenigen et al., 2010, Linquist et al., 2012, Van Kessel et al., 2013). Many previous studies focused mainly on assessing the effects of EENF on either crop yield or area-scaled N2O emission (Chen et al., 2008, Akiyama et al., 2010, Linquist et al., 2013, Abalos et al., 2014, Qiao et al., 2015, Gilsanz et al., 2016, Yang et al., 2016). The integrated effects of EENF on yield-scaled N2O emission and the corresponding key influencing factors are still unclear. Therefore, a meta-analysis based on peer-reviewed studies was conducted to (i) evaluate the effects of EENF on N2O emissions and agronomic performance, compared with conventional nitrogen fertilizer; (ii) evaluate the impacts of climate (aridity), soil properties (soil pH and texture), fertilizer application strategies (application rate, timing and placement), and soil tillage on the efficacy of EENF.
Section snippets
Data collection
A literature survey of peer-reviewed papers published before March 2015 reporting the results of the effects of EENF on N2O emission was carried out using the ISI-Web of Science and Google Scholar. The literature survey mainly focused on N2O emission from upland cropping systems including maize, wheat, and barley; horticulture crops were excluded. Only studies that met the following criteria were included: (i) the measurements were conducted under field conditions; (ii) N2O flux rate must have
Difference among crops and EENF products
On average, EENF significantly reduced area- and yield-scaled N2O emissions by 25.6% and 26.4%, respectively, compared with conventional N fertilizer. The NUE was significantly enhanced 10.2% by EENF (Fig. 1). No significant difference was found in the effects of EENF on N2O emission and crop yield among the crops of maize, wheat, and barley. However, the effects varied significantly among different EENF products. The IS significantly mitigated area-scaled N2O emission by 31.5% and increased
Study limitations
The EENF has many products, such as DCD (nitrification inhibitor), NBPT (urease inhibitor) and PCF (slow release fertilizer). Their pathway controlling the N releasing and transformation were different from each other. Some previous studies (Abalos et al., 2014, Gilsanz et al., 2016, Yang et al., 2016) have evaluated the efficacy of DCD and DMPP on crop yield or N2O emission under specific soil or management conditions. Besides nitrification inhibitors, this study synthetically analyzed the
Conclusion
This meta-analysis formulated two major generalizations regarding the effects of EENF on N2O emission and crop yield. First, IS showed significant effects on the mitigation of N2O emission and enhancement of crop yield; while S/CRF only significantly reduced N2O emission, its effect on crop yield was not significant. In general, S/CRF was less effective than IS on the mitigation of yield-scaled N2O emission. Second, the effects of IS and S/CRF were highly dependent on climate, soil properties,
Acknowledgement
This work was supported by the Innovation Program of Chinese Academy of Agricultural Sciences, the Special Fund for Agro-scientific Research in the Public Interest (201503116-10), and the State Key Program of China (2016YFD0300803).
References (64)
- et al.
Meta-analysis of the effect of urease and nitrification inhibitors on crop productivity and nitrogen use efficiency
Agric. Ecosyst. Environ.
(2014) - et al.
Effectiveness of 3,4-dimethylpyrazole phosphate as nitriflcation inhibitor in soil as influenced by inhibitor concentration, application Form, and soil matric potential1
Pedosphere
(2008) - et al.
NO, N2O, CH4 and fluxes in winter barley field of Japanese Andisol as affected by N fertilizer management
Soil Biol. Biochem.
(2007) - et al.
Legume versus fertilizer sources of nitrogen: ecological trade offs and human needs
Agric. Ecosyst. Environ.
(2004) - et al.
No-tillage and conventional tillage effects on durum wheat yield, grain quality and soil moisture content in southern Italy
Soil Tillage Res.
(2007) - et al.
Development of emission factors and efficiency of two nitrification inhibitors, DCD and DMPP
Agric. Ecosyst. Environ.
(2016) - et al.
A bioassay to determine the effect of organic matter and pH on the effectiveness of nitrapyrin (N-Serve) as a nitrification inhibitor
Soil Biol. Biochem.
(1979) - et al.
Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes
Environ. Pollut.
(2013) - et al.
Short-term competition between crop plants and soil microbes for inorganic N fertilizer
Soil Biol. Biochem.
(2010) - et al.
Linear and nonlinear dependency of direct nitrous oxide emissions on fertilizer nitrogen input: a meta-analysis
Agric. Ecosyst. Environ.
(2013)
Enhanced efficiency nitrogen fertilizers for rice systems: Meta-analysis of yield and nitrogen uptake
Field Crop. Res.
Dicyandiamide and 3,4-dimethyl pyrazole phosphate decrease N2O emissions from grassland but dicyandiamide produces deleterious effects in clover
J. Plant Physiol.
Nitrite intensity explains N management effects on N2O emissions in maize
Soil Biol. Biochem.
Mitigating nitrous oxide and methane emissions from soil in rice-wheat system of the Indo-Gangetic plain with nitrification and urease inhibitors
Chemosphere
Food consumption, diet shifts and associated non-CO2 greenhouse gases from agricultural production
Glob. Environ. Change
Advances in controlled-release fertilizers
Adv. Agron.
Feeding the world’s increasing population while limiting climate change impacts: linking N2O and CH4 emissions from agriculture to population growth
Environ. Sci. Policy
Evaluation of effectiveness of enhanced-efficiency fertilizers as mitigation options for N2O and NO emissions from agricultural soils: meta-analysis
Glob. Change Biol.
Nitrous oxide emissions from a clay soil receiving granular urea formulations and dairy manure
Agron. J.
Nitrous oxide emissions in Midwest US maize production vary widely with band-injected N fertilizer rates, timing and nitrapyrin presence
Environ. Res. Lett.
Nitrogen losses from fertilizers applied to maize, wheat and rice in the North China Plain
Nutr. Cycl. Agroecosys.
Prospects of improving efficiency of fertiliser nitrogen in Australian agriculture: a review of enhanced efficiency fertilisers
Soil Res.
Mitigating nitrous oxide emissions from corn cropping systems in the Midwestern U.S.: potential and data gaps
Environ. Sci. Technol.
Nitrous oxide emissions with enhanced efficiency nitrogen fertilizers in a rainfed system
Agron. J.
Nitrogen source, application time, and tillage effects on soil nitrous oxide emissions and corn grain yields
Soil Sci. Soc. Am. J.
Influence of urease and nitrification inhibitors on N losses from soils fertilized with urea
Biol. Fertil. Soils
Nitrogen release from environmentally smart nitrogen fertilizer as influenced by soil series, temperature, moisture, and incubation method
Commun. Soil Sci. Plant Anal.
Nitrogen source and placement effects on soil nitrous oxide emissions from no-till corn
J. Environ. Qual.
Nitrogen placement and source effects on nitrous oxide emissions and yields of irrigated corn
J. Environ. Qual.
Nitrogen source effects on nitrous oxide emissions from irrigated no-till corn all rights reserved
J. Environ. Qual.
Enhanced-efficiency nitrogen fertilizers: potential role in nitrous oxide emission mitigation
Agron. J.
Cited by (69)
Enhanced nitrogen fertilizer combined with straw incorporation can reduce global warming potential with higher carbon sequestration in a summer maize-winter wheat rotation system
2024, Agriculture, Ecosystems and EnvironmentOptimizing potassium and nitrogen fertilizer strategies to mitigate greenhouse gas emissions in global agroecosystems
2024, Science of the Total EnvironmentInnovative nitrogen management strategy reduced N<inf>2</inf>O emission while maintaining high pepper yield in subtropical condition
2023, Agriculture, Ecosystems and Environment