Optimized fertigation maintains high yield and mitigates N2O and NO emissions in an intensified wheat–maize cropping system

doi:10.1016/j.agwat.2018.09.045

Agricultural Water Management

Volume 211, 1 January 2019, Pages 26-36

https://doi.org/10.1016/j.agwat.2018.09.045 Get rights and content

Highlights

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Optimized fertigation significantly increased water and fertilizer N efficiencies.
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Optimized fertigation significantly reduced N₂O and NO emissions at a higher yield.
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Nitrifier denitrification was higher in flood fertigation and in summer season.

Abstract

Agricultural soil is a major source of N₂O and NO. In this study, we tested whether optimized N fertigation and water-saving irrigation methods could improve nutrient and water use efficiency while maintaining productivity in the intensified farmed winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) cropping system of northern China. A field experiment was conducted to test different flood irrigation (FN600, conventional N fertilization of 600 kg N ha⁻¹ yr⁻¹ and flood irrigation; FN0, no N input and flood irrigation) and drip fertigation (N0, no N input and drip irrigation; N420, optimized N fertilization of 420 kg N ha⁻¹ yr⁻¹ and drip irrigation; N600, conventional N fertilization of 600 kg N ha⁻¹ yr⁻¹ and drip irrigation) treatments. Compared with the FN600 treatment, the N600 treatment reduced water use by 62.5% (wheat season) and 36.4% (maize season). The N600 treatment significantly reduced N₂O emissions (by 19.9%) during the maize season, but not during the wheat season. The N600 treatment increased NO emissions by 20.9% and 11.0% during the wheat and maize seasons, respectively. Compared with the N600 treatment, the N420 treatment significantly decreased N₂O and NO emissions by 21.8% and 29.8%, respectively, during the wheat season, and by 31.5% and 41.6%, respectively, during the maize season, while achieving higher crop yield. The direct emission factors (ratio of the cumulative N₂O or NO emissions of fertilized treatment minus CK to N rate) of N₂O and NO were 0.19%–0.25% and 0.21%–0.27% for the wheat season and 0.38%–0.63% and 0.34%–0.42% for the maize season, respectively. Optimal fertilization (N420) significantly increased the water use efficiency, intrinsic water use efficiency, partial factor productivity, and apparent nitrogen use efficiency in both the wheat and the maize seasons. In addition to nitrification, nitrifier denitrification contributed to the generation and diffusion of N₂O and NO, especially during the summer maize season. Considering the higher productivity, more efficient use of irrigation water and nitrogen, and lower N₂O and NO emissions, drip irrigation combined with optimized N fertilization is recommended in northern China.

Graphical abstract

Introduction

Globally, agricultural soils contribute approximately 67% and 18% of total anthropogenic N₂O and NO emissions, respectively (Reay et al., 2012; Gaihre et al., 2015). Total fertilized cropland annually emits 1.7–4.8 Tg of N₂O-N and 1.6–8.9 Tg of NO-N (IPCC, 2007; Cui et al., 2012; Yao et al., 2017). Accordingly, it is important to mitigate N₂O and NO emissions through optimized farming practices in agricultural sectors.

Drip irrigation combined with dissolved N fertilizer (fertigation), which provides an appropriate amount of N and water to crop roots in a more precise and timely manner than does broadcast fertilization, has been confirmed to be an efficient method of irrigation and fertilization (Abalos et al., 2014; Farneselli et al., 2015). Many studies have shown that drip fertigation can decrease N losses (Badr et al., 2012; Koocheki et al., 2014) and reduce transformable N to N₂O and/or NO (Maris et al., 2015). Wang et al. (2016a) reported a significant reduction (14.6%) of N₂O in the winter wheat season under drip irrigation, compared with flood irrigation. However, Tian et al. (2016) found that drip fertigation reduced N₂O emissions by 7.7%, but increased NO emissions by 21.7% during the summer maize season. These findings indicated that edaphic properties, climate conditions, and farming practices may exert different effects on soil N₂O and NO emissions (Barnard et al., 2005; Deppe et al., 2016; Zhou et al., 2017).

Northern China, one of the most intensified agricultural regions in China, produced 67% and 28% of the nation’s wheat (Triticum aestivum L.) and maize (Zea mays L.), respectively, in 2014 (NBSC, 2015). Various sound farming practices have been implemented to reduce fertilizer N and water inputs and maintain the high crop yield in this region since the 1990s (Zhang et al., 2011). The fertilizer N efficiency in the region has been reported to be <30% for maize and wheat (Miao et al., 2011). The reported proportions of N losses from applied fertilizers via nitrification and denitrification range from 0.9% to 10.9% (Zhang et al., 2008; Ju et al., 2009). Such gaseous N losses (including NH₃) exert potential pressure on the aquatic environment (Chien et al., 2009) and air quality (Xu et al., 2016), and contribute to regional and global greenhouse gas emissions (Zhang et al., 2017). In northern China, agriculture is dependent on pumping deep groundwater for irrigation, and irrigation water accounts for 80% of total water use in the region (Deng et al., 2006). As a result, the groundwater level is declining rapidly at a rate of 0.8 m yr⁻¹ in this region (Fang et al., 2010). Heavy irrigation has also increased NO₃⁻ leaching from cropland (Deng et al., 2006), resulting in the entry of NO₃⁻ to deeper profiles, after which it infiltrates groundwater or is permanently lost from the system (Currell et al., 2012). Optimizing fertilization and irrigation by methods such as sprinkling and drip irrigation has been suggested as a priority farming measure and is being expanded in the region. Currently, these processes are applied to >1 million ha of maize and >0.3 million ha of wheat agricultural areas, with a target of total 2.7 million ha in China by 2020 (the “Promotion of Implementation of Fertigation” policy; MOA, 2016).

In this study, we hypothesized that drip fertigation would substantially decrease N₂O emissions but increase NO production because of higher oxidation of N₂O to NO during drip fertigation than during flood irrigation. To test this hypothesis, we monitored the N₂O and NO losses, crop production, and soil conditions in northern China under flood and drip irrigation with different N rates in the typical winter wheat–summer maize cropping system of the region. We aimed to analyze the effects of optimized fertilization and irrigation on crop production and N₂O and NO emissions. The overall aim of this research is to develop appropriate practices to mitigate the production of greenhouse gases and improve resource use while maintaining high land productivity.

Section snippets

Study area

We initiated the field experiment in 2015 at the Huantai Experimental Station of China Agricultural University, Shandong province (36°51′50″–37°06′00″N, 117°50′00″–118°10′40″E). The region has a typical continental monsoon climate, with an annual average temperature of 12.5 °C (Chen et al., 2010). Rainfall occurs mainly in June, July, and August. The annual precipitation is 542.8 mm and the annual frost-free season is about 198 days (Liao et al., 2015). The soil parent materials are mainly

Climate and soil conditions

During the study period, the higher frequencies of fertilization/irrigation events in drip irrigation (11 times) than in flood irrigation (four times) treatments caused the mean soil temperature to be 13.9 °C (wheat season) and 25.2 °C (maize season) in the flood irrigation treatments (FN600 and FN0). These values were significantly higher than those in the drip irrigation (N600, N400, and N0) treatments (by 9.4% and 5% in wheat and maize season, respectively; Table 1, Fig. 1, Fig. 2). Soil

N₂O and NO generation and diffusion in alkaline agricultural soils

Both N₂O and NO are produced through the microbial processes of nitrate dissimilation (denitrification and nitrate ammonification) and nitrification (ammonia oxidation and nitrifier denitrification) and through abiotic chemo-denitrification reactions (Baggs, 2008; Kool et al., 2011; Zhu et al., 2013). In previous studies, the NO emissions from agricultural fields were mainly ascribed to nitrification, whereas the N₂O emissions were ascribed to both nitrification and denitrification (Maljanen et

Conclusions

Drip fertigation and flood irrigation with synthetic N fertilizer in a winter wheat–summer maize cropping system in northern China resulted in different N₂O and NO emissions. Drip fertigation (at the same N level as FN600) significantly reduced N₂O emissions by 19.9% during the maize season but did not significantly affect significant N₂O emissions during the wheat season, and increased the NO emissions in the wheat and maize seasons by 20.9% and 11.0%, respectively, when compared with flood

Acknowledgements

This study was supported by the State's Key Project of Research and Development Plan (2016YFD0800104 and 2017YFD0800605). We thank the anonymous reviewers for their valuable comments, which greatly improved the manuscript. We thank Jeremy Kamen, MSc, and Jennifer Smith, PhD, from Liwen Bianji, Edanz Group China (www.liwenbianji.cn/ac), for editing the English text of drafts of this manuscript.

References (56)

D. Abalos et al.
Management of irrigation frequency and nitrogen fertilization to mitigate GHG and NO emissions from drip-fertigated crops
Sci. Total Environ.
(2014)
A.D. Al-Qurashi et al.
Growth, yield, fruit quality and nutrient uptake of tissue culture-regenerated ‘Barhee’ date palms grown in a newly established orchard as affected by NPK fertigation
Sci. Hortic. Amsterd.
(2015)
M.A. Badr et al.
Yield and water use efficiency of potato grown under different irrigation and nitrogen levels in an arid region
Agric. Water Manage.
(2012)
S. Chen et al.
The effects of land use change and irrigation water resource on nitrate contamination in shallow groundwater at county scale
Ecol. Complex.
(2010)
S. Chien et al.
Recent developments of fertilizer production and use to improve nutrient efficiency and minimize environmental impacts
Adv. Agron.
(2009)
Z. Cui et al.
On-farm evaluation of an in-season nitrogen management strategy based on soil N min test
Field Crop. Res.
(2008)
F. Cui et al.
Annual emissions of nitrous oxide and nitric oxide from a wheat–maize cropping system on a silt loam calcareous soil in the North China Plain
Soil Biol. Biochem.
(2012)
X.P. Deng et al.
Improving agricultural water use efficiency in arid and semiarid areas of China
Agric. Water Manage.
(2006)
M. Deppe et al.
Impact of CULTAN fertilization with ammonium sulfate on field emissions of nitrous oxide
Agric. Ecosyst. Environ.
(2016)
W. Ding et al.
Nitrous oxide emissions from an intensively cultivated maize-wheat rotation soil in the North China Plain
Sci. Total Environ.
(2007)

Q.X. Fang et al.

Water resources and water use efficiency in the North China Plain: current status and agronomic management options

Agric. Water Manage.

(2010)

M. Farneselli et al.

High fertigation frequency improves nitrogen uptake and crop performance in processing tomato grown with high nitrogen and water supply

Agric. Water Manage.

(2015)

Y.K. Gaihre et al.

Impacts of urea deep placement on nitrous oxide and nitric oxide emissions from rice fields in Bangladesh

Geoderma

(2015)

B. Gao et al.

The impact of alternative cropping systems on global warming potential, grain yield and groundwater use

Agric. Ecosyst. Environ.

(2015)

J. Holst et al.

Crop evapotranspiration, arable cropping systems and water sustainability in southern Hebei, P.R. China

Agric. Water Manage.

(2014)

X.K. Hu et al.

Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes

Environ. Pollut.

(2013)

T. Huang et al.

Effect of fertilizer N rates and straw management on yield-scaled nitrous oxide emissions in a maize-wheat double cropping system

Field Crop. Res.

(2017)

X. Ju et al.

Processes and factors controlling N₂O production in an intensively managed low carbon calcareous soil under sub-humid monsoon conditions

Environ. Pollut.

(2011)

D.M. Kool et al.

Nitrifier denitrification as a distinct and significant source of nitrous oxide from soil

Soil Biol. Biochem.

(2011)

L. Liang et al.

Structural change and carbon emission of rural household energy consumption in Huantai, northern China

Renew. Sust. Energ. Rev.

(2013)

M. Maljanen et al.

Fluxes of nitrous oxide and nitric oxide from experimental excreta patches in boreal agricultural soil

Soil Biol. Biochem.

(2007)

S.C. Maris et al.

Effect of irrigation, nitrogen application, and a nitrification inhibitor on nitrous oxide, carbon dioxide and methane emissions from an olive (Olea europaea L.) orchard

Sci. Total Environ.

(2015)

A. Meijide et al.

Nitrogen oxide emissions from an irrigated maize crop amended with treated pig slurries and composts in a Mediterranean climate

Agric. Ecosyst. Environ.

(2007)

L. Sanchezmartin et al.

Influence of drip and furrow irrigation systems on nitrogen oxide emissions from a horticultural crop

Soil Biol. Biochem.

(2008)

G. Wang et al.

Mitigated CH₄ and N₂O emissions and improved irrigation water use efficiency in winter wheat field with surface drip irrigation in the North China Plain

Agric. Water Manage.

(2016)

Y. Wang et al.

CH₄, NH₃, N₂O and NO emissions from stored biogas digester effluent of pig manure at different temperatures

Agric. Ecosyst. Environ.

(2016)

M.W. Wolff et al.

Effects of drip fertigation frequency and N-source on soil N₂O production in almonds

Agric. Ecosyst. Environ.

(2017)

N. Wrage et al.

Role of nitrifier denitrification in the production of nitrous oxide

Soil Biol. Biochem.

(2001)

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Sub-surface drip irrigation reduced N<inf>2</inf>O emissions via inhibiting denitrification pathways in northern China
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Water-saving irrigation has become an important method for alleviating water scarcity in semi-arid regions. However, the lack of knowledge about the effects of different water-saving irrigation techniques on soil nitrogen conversion limits the understanding of the underlying mechanisms involved in soil N₂O emissions. To determine the effects of different irrigation methods on N₂O emissions, we conducted a two-season experiment under four different irrigation methods (DI, surface drip irrigation; SDI, sub-surface drip irrigation; PRI, partial rootzone irrigation; FP, flood irrigation). Also, we studied the dynamics of nitrifier and denitrifier community structures and compositions and their associations and effects on N₂O emissions. The results showed that seasonal N₂O emissions were affected by irrigation practices and significantly correlated with the amount of irrigation and soil moisture. Drip irrigation significantly reduced N₂O emissions, with 38–45 % (DI), 51–59 % (SDI), and 64–68 % (PRI) decreases compared to FP treatment. Under SDI, the copy numbers of ammonia-oxidizing archaea amoA significantly decreased and nirK displayed an increase compared to FP. The abundance of unclassified_Proteobacteria dominant among nirK-type denitrifiers under FP was observed to be strongly and positively correlated with N₂O emissions, and the dominant bacteria shifted to Bosea under drip irrigation. Irrigation practices had a strong effect on the Shannon and ACE indexes of five key genes. PRI showed a similar effect under SDI treatment on nitrifier and denitrifier community structures. Furthermore, PRI, with only a 38 % reduction of irrigation water consumption, produced a 4.4–11.3 % lower yield than SDI. Therefore, SDI treatment can inhibit the denitrification process led by nirS-type denitrifiers and reduce the abundance of the dominant genus of nirK and promote nosZ abundance, thus decreasing N₂O emissions. Our findings indicate that (i) drip irrigation increased ammonia-oxidizing bacteria amoA abundance and diversity but decreased nirS abundance, which led to N₂O mitigation and (ii) SDI might be the best method for maintaining high crop yield with lower N₂O emissions in intensively farmed fields.
Improving potential of reactive nitrogen and carbon footprint of intensified greenhouse cucumber-tomato production with optimized drip irrigation with nitrogen reduction strategies
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Guaranteeing a robust supply of vegetables is a significant public welfare endeavor. However, the implementation of irrational water and fertilizer regimes in greenhouse vegetable fields (GVF) has resulted in adverse environmental impacts. Therefore, it is crucial to develop water and fertilizer regimes to maintain the productivity of greenhouse vegetables with less carbon (C) and reactive nitrogen (Nr) footprint. A four growing seasons experiment involving the cultivation of cucumbers and tomatoes was conducted in the suburbs of Beijing. The experiment comprised three treatments: flood irrigation with a conventional urea-N application (FN), drip fertigation with a conventional urea-N application (DN), and drip fertigation with a 50% reduction of urea-N application (DRN). The results showed that about 70% of annual N inputs in GVF were surplus, posing a high risk of loss. For the FN treatment, the N budget, Nr loss, Nr footprint per unit of vegetable yield (NrF_Y), Nr footprint per unit of net return (NrF_R), greenhouse gas (GHG) emissions, C footprint per unit of vegetable yield (CF_Y), C footprint per unit of net return (CF_R) were respectively quantified as follows: 1653 kg N ha⁻¹ yr⁻¹, 776 kg N ha⁻¹ yr⁻¹, 4.39 kg N t⁻¹ yr⁻¹, 24.48 kg N ¥10000⁻¹ yr⁻¹, 46548 kg CO₂-eq ha⁻¹ yr⁻¹, 262.98 kg CO₂-eq t⁻¹ yr⁻¹ and 1467.58 kg CO₂-eq ¥10000⁻¹ yr⁻¹. Compared with FN, DN significantly reduced Nr loss (25%), NrF_Y (24%), NrF_R (22%), GHG emissions (6%), CF_Y (4%), while it increased N surplus (9.7%) and produced lower farmers' net return (¥ 13486 ha⁻¹ yr⁻¹). Concurrently, DRN significantly reduced the N surplus, Nr loss, NrF_Y and NrF_R by ∼35%, decreased the GHG emissions, CF_Y and CF_R by ∼20%, and improved farmers' net return by ¥ 674 ha⁻¹ yr⁻¹ compared to FN treatment. Therefore, this study highlighted that an integrated water and fertilizer regulation strategy (drip irrigation replacing flood irrigation coupled with a 50% reduction in chemical N application) can simultaneously achieve environmental and economic benefits in the context of high N inputs. This contributes to the sustainable development of intensive vegetable cultivation systems.
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Drip fertigation can synchronize the supply of nutrients and water for crop demand, offering the potential for minimizing negative environmental impacts and sustaining crop productivity. However, there are no comprehensive evaluations on performances of drip fertigation on environmental nitrogen (N) losses and crop productivity, nationwide. Here, a meta-analysis was performed to quantify overall effects of drip fertigation on N losses and crop productivity in Chinese agricultural systems based on 443 observations from 42 field studies. The results showed that drip fertigation significantly increased crop yields by 9.8 % and slightly increased soil NO emission by 13.9 % compared to the traditional irrigation and fertilization practices (e.g. flooding/furrow irrigation and N broadcasting), while significantly decreasing NH₃ volatilization by 14.2 %, soil N₂O emission by 28.1 % and NO₃⁻–N leaching loss by 71.2 %. There were significant mitigation potentials of environmental N losses by drip fertigation for cereal cropping systems, not for horticultural crops in terms of soil NO emission and not for cotton in terms of NH₃ volatilization. Non significant promotion effect on NO emission and significant reduction effects on the other all kinds of environmental N losses by drip fertigation were observed for alkaline soils (pH > 7.3) and coarse-textured soils. In addition, the use of different fertilizer sources and/or soil amendments have shown in popularity as strategies to offset the negative feedback associated with agricultural N losses, no direct synthetic result was shown in drip-fertigated soils. We synthesized 19 studies so as to assess the potential mitigation options for further minimizing N losses in drip fertigation systems, which suggested that deleterious environmental pollution could be further reduced while still achieving high crop yields with a combination of enhanced-efficiency fertilizers (e.g. nitrification or urease inhibitors) or soil amendments (e.g. biochar or straw) to drip fertigation systems.
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Nitrous oxide (N₂O) emissions from agroecosystems are a major contributor to global warming and stratospheric ozone depletion. However, knowledge concerning the hotspots and hot moments of soil N₂O emissions with manure application and irrigation, as well as the underlying mechanisms remain incomplete. Here, a 3-year field experiment was conducted with the combination of fertilization (no fertilizer, F0; 100% chemical fertilizer N, Fc; 50% chemical N + 50% manure N, Fc + m; and 100% manure N, Fm) and irrigation (with irrigation, W1; and without irrigation, W0; at wheat jointing stage) for winter wheat – summer maize cropping system in the North China Plain. Results showed that irrigation did not affect annual N₂O emissions of the wheat-maize system. Manure application (Fc + m and Fm) reduced annual N₂O emissions by 25–51% compared with Fc, which mainly occurred during 2 weeks after fertilization combined with irrigation (or heavy rainfall). In particular, Fc + m reduced the cumulative N₂O emissions during 2 weeks after winter wheat sowing and summer maize top dressing by 0.28 and 0.11 kg ha⁻¹, respectively, compared with Fc. Meanwhile, Fm maintained the grain N yield and Fc + m increased grain N yield by 8% compared with Fc under W1. Overall, Fm maintained the annual grain N yield and lower N₂O emissions compared to Fc under W0, and Fc + m increased the annual grain N yield and maintained N₂O emissions compared with Fc under W1, respectively. Our results provide scientific support for using manure to minimize N₂O emissions while maintaining crop N yield under optimal irrigation to support the green transition in agricultural production.

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Optimized fertigation maintains high yield and mitigates N2O and NO emissions in an intensified wheat–maize cropping system

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Study area

Climate and soil conditions

N2O and NO generation and diffusion in alkaline agricultural soils

Conclusions

Acknowledgements

Sci. Total Environ.

Sci. Hortic. Amsterd.

Agric. Water Manage.

Ecol. Complex.

Adv. Agron.

Field Crop. Res.

Soil Biol. Biochem.

Agric. Water Manage.

Agric. Ecosyst. Environ.

Sci. Total Environ.

Agric. Water Manage.

Agric. Water Manage.

Geoderma

Agric. Ecosyst. Environ.

Agric. Water Manage.

Environ. Pollut.

Field Crop. Res.

Environ. Pollut.

Soil Biol. Biochem.

Renew. Sust. Energ. Rev.

Soil Biol. Biochem.

Sci. Total Environ.

Agric. Ecosyst. Environ.

Soil Biol. Biochem.

Agric. Water Manage.

Agric. Ecosyst. Environ.

Agric. Ecosyst. Environ.

Soil Biol. Biochem.

Optimized fertigation maintains high yield and mitigates N₂O and NO emissions in an intensified wheat–maize cropping system

N₂O and NO generation and diffusion in alkaline agricultural soils