Long-term atmospheric wet deposition of dissolved organic nitrogen in a typical red-soil agro-ecosystem, Southeastern China.

Environmental Science Processes & Impacts View Article Online

Published on 04 February 2014. Downloaded by Universitat Autonoma de Barcelona on 29/10/2014 09:42:51.

PAPER

Cite this: Environ. Sci.: Processes Impacts, 2014, 16, 1050

View Journal | View Issue

Long-term atmospheric wet deposition of dissolved organic nitrogen in a typical red-soil agro-ecosystem, Southeastern China Jian Cui,*ab Jing Zhou,*ab Ying Peng,c Yuan Q. He,ab Hao Yang,d Liang J. Xud and Andy Chane Dissolved organic nitrogen (DON) from atmospheric deposition has been a growing concern in the world and atmospheric nitrogen (N) deposition is increasing quickly in China especially Southeastern China. In our study, DON wet deposition was estimated by collecting and analyzing rainwater samples continuously over eight years (2005–2012) in a typical red-soil farmland ecosystem, Southeast China. Results showed that the volume–weighted–average DON concentration varied from 0.2 to 3.3 mg N L1 with an average of 1.2 mg N L1. DON flux ranged from 5.7 to 71.6 kg N ha1 year1 and averaged 19.7 kg N ha1 year1 which accounted for 34.6% of the total dissolved nitrogen (TDN) in wet deposition during the eight-year period. Analysis of DON concentration and flux, contribution of DON to TDN, rainfall, rain frequency, air temperature and wind frequency and the application of pig manure revealed possible pollution sources.

Received 18th November 2013 Accepted 4th February 2014

Significant positive linear relation of annual DON flux and usage of pig manure (P < 0.0001) suggested

DOI: 10.1039/c3em00613a

that agricultural activities, especially application of pig manure, were the main source of DON in the study area. In conclusion, DON wet deposition was an important part of TDN and would have a possible

rsc.li/process-impacts

effect on N cycle in the red-soil agro-ecosystem in the future.

Environmental impact Dissolved organic nitrogen (DON) in atmospheric wet deposition into a typical agro-ecosystem in Southeast China was investigated experimentally in 2005–2012. Spatiotemporal variability of DON wet deposition in various farmland ecosystems is integrated to estimate the effects of DON deposition on the ecosystem. We estimate its deposition ux and evaluate its contribution to the farmland ecosystem in order to give reliable data for agriculture productivity, such as a valuable parameter for assessing the effect of N deposition on agro-ecosystems and attribute to the understanding of N-cycling and its nutrient management of agroecosystems in China and also around the world.

1. Introduction Over the past century, human activities have more than doubled the global nitrogen (N) ux, which in turn has produced an important effect on plant growth, biodiversity and ecosystem function.1–3 Previous studies on N-deposition mostly focused on forest and aquatic ecosystems but generally neglected agroecosystems due to substantial use of N-fertilizers on

a

Institute of Soil Science, Chinese Academy of Sciences, 71st East Beijing Road, Nanjing, Jiangsu, P.R. China. E-mail: [email protected]; [email protected]

b

National Engineering and Technology Research Center for Red Soil Improvement, Red Soil Ecological Experiment station, Chinese Academy of Sciences, Liujiazhan plantation, Yingtan Jiangxi, P.R. China

c Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73st East Beijing Road, Nanjing, Jiangsu, P.R. China d

College of Geography Science, Nanjing Normal University, 1st Wenyuan Road, Nanjing, Jiangsuu, P.R. China

e

Division of Environment, University of Nottingham Malaysia Campus, Semenyih 43500, Selangor, Malaysia

1050 | Environ. Sci.: Processes Impacts, 2014, 16, 1050–1058

farmlands.4,5 In fact, it had been discovered that N wet deposition ranged from 10 to 94 kg N ha1 year1,6,7 which was signicantly greater than the global average of 3.5 N kg ha1 year1.8 Moreover, there have been only a few reports on dissolved organic N (DON) deposition for its different chemical families, low concentrations and instability aer collection (Cape et al., 2011; Cornell, 2011; Zhang et al., 2012).9–11 In fact, DON is of similar bioavailability to inorganic N and plays an important role in N-deposition with a signicant fraction (33 19%) of TDN deposition.11,12 Excluding DON will underestimate the TDN deposition and hence an improved quantitative understanding of DON in the agro-ecosystem is needed to complement our knowledge of DIN and TDN. In China, N-deposition increased by approximately 8 kg N ha1 year1 between the 1980s and 2000s,3 while China and other economies are facing a continuous challenge to reduce nitrogen emission, deposition and their negative effects on human health and the environment.1,3,10 However, current research on DON deposition is mainly focused on Europe and

This journal is © The Royal Society of Chemistry 2014

View Article Online


Paper

Environmental Science: Processes & Impacts

America.10,13,14 In China, the studies of N deposition including DON deposition are still at the initial stage and focus on forest and aquatic ecosystems.15–17 There are only a few reports on DON deposition with the study periods limited to one-to-two years,7,10,14 especially in agricultural ecosystems. This has affected the consistency and reliability of data of DON deposition. It is necessary to estimate DON deposition and assess its contribution to TDN in a long-term observation especially in Chinese agro-ecosystems. Southeastern China also has some of the highest N deposition in the world, with rates similar to those of central Europe and eastern North America.18 Moreover, the red soils in context are highly leached soils usually designated under the orders of Oxisols, Ultisols, occasionally Alsols, Mollisols and even Inceptisols.19 The red soils of China are highly weathered and inherently infertile, dominated by low mountains and hills, and are typical of similar red soils that occur throughout (sub-) tropical South America, Africa, South and East Asia and other regions. Red soils are generally acidic in nature and decient in most essential nutrients.19 Larger amounts of organic matter and nutrients are also lost from the cultivated land,20 making the agro-ecosystems fragile. Moreover, the red soil regions of China are typically located in the acid rain zone. N deposition including DON deposition might have a great ecological effect on, for example, the yields, acidication and alteration of nutrient balances of agricultural ecosystems. Along this line, the characteristics and effects of DON deposition on red soil agro-ecosystems is still unclear, especially in the long term. In the current study, we focused on a typical agro-ecosystem in the red soil region, Southeastern China: (1) to quantify DON wet deposition, and (2) to characterize the sources of DON using correlation analysis with various meteorological factors (rainfall, rain frequency, air temperature, wind direction) through long-term observation (2005–2012). These results not only give a more comprehensive assessment of DON in atmospheric N-deposition, but also supply a valuable parameter for assessing the effect of N deposition on agro-ecosystems and attribute to the understanding of N-cycling and its nutrient management of red-soil agro-ecosystems in China and also around the world.

2. 2.1

Materials and methodologies Study site

Yingtan city lies in the northern part of Jiangxi province, Southeast China (116 350 -117 300 E, 27 350 -28 410 N), and covers a total area of 3556.7 km2 (Fig. 1). The primary soil is red soil. Geomorphologically, the city consists of hills, basins and high, steep, clustered mountains in its northern, central and southern areas. Its ground elevation varies from 16 to 1541 m above the sea level. Subtropical humid monsoon climate prevails in the city, with an annual mean air temperature of 18 C, abundant annual rainfall (1750 mm), and a leading southwest wind direction during June to August while that of east and northeast in the other nine months. Atmospheric precipitation in the present study was collected at the Red Soil Ecological Experiment Station (116 550 E, 28 120 N), Chinese Academy of Sciences (CAS) in the northeast of


Yingtan city, usually known as Yingtan Station (YTS) (Fig. 1). YTS is a typically hilly region of red soil in subtropical China with a typical monsoon climate and detailed meteorological factors during the sampling period were provided in Fig. 2 and Fig. 3a–c. YTS has been selected as a long-term agro-ecosystem monitoring site by CAS, as well as a global environment-climate observation station. It covers a total area of 120 ha, and is composed of 75% farmland, 15% forestland, 10% other land such as water bodies, roads and residential areas. The crops, including peanut and rice, were mainly planted in April, June and July. Usually, chemical N-fertilizers (urea, ammonium bicarhonate and compound fertilizers) with 120–480 kg N ha1 year1 were applied in regional elds and pig manure (20 kg N) was transported into a eld (0.07 ha) near the sampling site during November to December and applied in March and April every year. In addition, the application of pig manure (about 300 kg N) was conducted in the elds on April 28th 2006, August 25th 2006 and March 13th 2007, respectively. There are three pig farms within 50 km2 area. One pig farm is located in the direction of north-northwest to north and the other two are in the east-southeast to east in the sample site, respectively.

2.2

Sample collection and analysis

Eight-year observation was established to determine DON wet deposition in a typical red soil agroecosystem during 2005– 2012. The auto precipitation and dust sampler (ASP-2, Wuhan Tianhong Inc., China) was employed to collect wet-only N deposition. During rain events, a wetness detector was triggered to open the lid of the wet deposition bucket. Once the rain stopped, the lid closed and sealed the bucket to prevent evaporation and contamination of the sample. The samples were collected immediately aer each rain event during 2003–2004 and 2010–2012, whereas those were obtained at a 4 week interval during 2005–2009. To eliminate the effects of microbial activities on rainwater chemical compositions during the 4 week intervals, some doses of methyl-propyl phenol (analytically pure) were added to rainwater samples at the base of the rainfall aer every event (ratio of methyl-proyl phenol to rainwater sample ¼ 450 mg to 1 L).21 Polyethylene collection bottles were carefully cleaned with acid washed with 10% HCl solution and deionised water.22 DON in wet deposition consists of a variety of compounds, such as urea, amino acid, amines and so on. In this study, rather than identifying the specic compositions of DON, we would quantify the importance of DON in wet deposition and thus we only determine the bulk DON concentrations in our rainwater samples. Because of low or trace concentration of nitrite N (NO2–N) in regional rainwater samples,23,24 DON concentrations in the samples were dened as the difference between the total dissolved nitrogen (TDN) and the dissolved inorganic nitrogen (DIN), i.e. DON ¼ TDN DIN ¼ TDN (NH4+–N + NO3–N). Samples were shaken for 2–3 min to agitate the sunken particles at the bottom of these containers and then were ltered through 0.45 mm-cellulose membrane lters in the laboratory and frozen prior to subsequent chemical analyses.

Environ. Sci.: Processes Impacts, 2014, 16, 1050–1058 | 1051

View Article Online



Fig. 1

The study site in Yingtan city, Jiangxi Province, China.

TDN was measured by an alkaline potassium peroxydisulphate oxidation method (APOM).25,26 The concentrations of NO3–N and NH4+–N were performed following a standard procedure with a continuous ow analyser AutoAnalyzer 3 (Bran-Luebbe Inc., Germany). In some samples, NH4+–N was analyzed using the indophenols blue method followed by colorimetry at a wavelength of 625 nm, whereas NO3–N was directly calculated by the absorbance difference at wavelengths of 220 and 275 nm.27,28 Method detection limits (MDL) were 0.01, 0.02 and 0.05 mg L1 N for NH4+–N, NO3–N and TDN, respectively. The

Fig. 2

Paper

average concentrations of the N species in the eld blanks were well below the MDL, thereby indicating that no signicant contamination of the samples occurred during the sampling, handling, ltration or measurement steps. Moreover, the recoveries of NH4+–N and NO3–N spiked to rainwater were determined by the AutoAnalyzer 3. NH4+–N and NO3–N standard solutions were both set at eight levels: 0.2, 0.4, 0.6, 0.8, 1.2, 1.6, 2.4 and 3.2 mg N L1. The recoveries of NH4+- and NO3–N ranged from 90.3 to 101.8% and from 91.9 to 100.7%, respectively.

Monthly wind frequency rose during the sampling period.



View Article Online


Paper


Fig. 4 Correlation of annual DON flux and usage of pig manure in the

sampling years. Data of pig manure came for our investigations and records in the YTS.

2.3

Data analysis

Wet deposition was calculated using eqn (1) and (2) X n n X Cw ¼ ðCi Pi Þ Pi i¼1

Fig. 3 Monthly average rainfall, rain frequency, air temperature, and monthly concentrations, deposition fluxes and contributions in the study ((a) rainfall; (b) rain frequency; (c) air temperature; (d) volumeweighted DON concentrations; (e) DON deposition fluxes; (f) contributions of DON to TDN).

where Cw is the precipitation-weighted mean concentration (mg N L1) calculated from n valid samples within one year, and the concentration of an individual valid sample Ci is weighted by the amount Pi of rain height for each sample. Fw ¼ PtCw/100

Correlations of monthly DON concentration (y) with monthly rainfall (x1), rain frequency (x2) and air temperature (x3) (n ¼ 96) Table 1

Rainfall (x1) Rain frequency (x2) Air temperature (x3)

Table 2

Equation

r2

P

y ¼ 0.008x1 + 0.544 y ¼ 0.131x2 0.032 y ¼ 0.0234x3 + 1.337

0.1034 0.0473 0.0042

0.0014 0.0334 0.5286

(1)

i¼1

(2)

where Fw is the wet-deposition ux (kg N ha1), Pt is the total rainfall (mm), and 100 is a percentage conversion factor. Descriptive statistics were used to characterize the monthly wet DON deposition during the sampling period (2005–2012). Wind directions (0–360 ) were divided into 16 equal parts: north (0 /360 ), north-northeast (22.5 ), northeast (45 ), east-northeast (67.5 ), east (90 ), east-southeast (112.5 ), southeast (135 ), south-southeast (157.5 ), south (180 ), south-southwest (202.5 ),

Annual means in rain fall, rain frequency, Cw(DON), Fw(DON) and contributions of DON to DIN and TDN during 2005–2012a Contribution (%)

2005 2006 2007 2008 2009 2010 2011 2012 Mean a

Rainfall (mm)

Rain frequency (d)

Cw(DON) (mg L1 N)

Fw(DON) (kg ha1 year1 N)

DON to DIN

DON to TDN

1659.6 b 1932.6 ab 1392.8 b 1493.2 b 1303.5 b 2615.9 a 1470.3 b 2624.7 a 1811.6

164 abc 145 c 158 abc 152 bc 143 c 193 ab 167 abc 197 a 165

1.1 bc 3.3 a 1.8 b 1.2 bc 1.0 bc 0.2 c 0.6 c 0.8 bc 1.2

11.0 b 71.6 a 28.9 b 9.6 b 9.1 b 6.3 b 5.7 b 15.5 b 19.7

52.3 bc 169.5 a 76.4 bc 77.6 bc 26.9 bc 16.8 c 24.6 bc 85.9 b 66.2

44.7 b 64.8 a 48.6 b 21.0 b 26.4 b 13.2 b 18.2 b 39.6 b 34.6

Note: the letters following the data stand for the different signicant differences at 5% level in the same column.



View Article Online

Environmental Science: Processes & Impacts Table 3

Paper

Comparison of wet N deposition fluxes in the farmland regions in China


Fluxes (kg ha1 year1 N) Site/Region

Collection year

Rainfall (mm)

DON

DIN

TDN

Ref.

The present site The whole China Shanghai Beijing Changshu, Jiangsu Wuxi, Jiangsu Shenyang, Liaoning Jurong, Jiangsu Yulin, Shanxi Yucheng, Shandong Luancheng, Hebei Xi'an, Shanxi Fengqiu, Henan Jiangle, Fujian

2005–2012 1993 1998–2003 1999–2004 2003–2005 2003–2005 2004–2008 2007–2008 2007–2008 2007–2010 2007–2010 2008 2009–2010 2010–2011

1811.6 — — 449.6 1222 1180 532.1 — 379 566 517 586

19.7

29.6 9.9 58.1 30.6 27.9 26.3 14.4 26.9 22.2 22.1 24.8 13.1 32.2 11.8

49.3 — — — — — 18.9 32.1 — — — — 40.3 17

— 40 41 11 and 42 43

1197

southwest (225 ), west-southwest (247.5 ), west (270 ), westnorthwest (292.5 ), northwest (315 ), north-northwest (337.5 ). One-way Analysis of Variance (ANOVA) was performed to demonstrate annual variations in wet DON deposition.

3. 3.1

Results and discussions Monthly variations

Monthly Cw(DON), Fw(DON) and the contribution of Fw(DON) to Fw(TDN) were in the ranges of 0.01–6.13 mg N L1, 0.01–16.93 kg N ha1 and 0.5–82.2% during 2005–2012, respectively (Fig. 3d–f). Higher Cw(DON) and Fw(DON) were mostly found in the application period (March–June) and transportation period (November–December) of fertilizers especially for pig manure in

7

4.5 5.2 — — — — 8.1 5.2

31 44 45 7 46 26 33

the study region. At times, higher levels of Cw(DON) and Fw(DON) also appeared in August and September when straws of peanut and early rice were oen burnt in open air. The agricultural activities above led to higher monthly Fw(DON), further to higher monthly contributions of DON to TDN (Fig. 3d–f). Furthermore, meteorological factors and distributions of pig manure also affected DON deposition in the study region. Monthly Fw(DON) had a positive linear relation with monthly rainfall, rain frequency and air temperature (Table 1). Signicant correlations were found between monthly Fw(DON) and rainfall, Fw(DON) and rain frequency (p < 0.05). During the months from March to June, the sum of rainfall and rain frequency ranged from 775.9 to 1333.6 mm and from 59 to 197 d

Fig. 5 Correlations of DON with NH4+–N, NO3–N, TDN during 2005–2012 ((a) monthly DON concentration vs. monthly NH4+–N concentration; (b) monthly DON concentration vs. monthly NO3–N concentration; (c) monthly DON concentration vs. monthly TDN concentration).



View Article Online


Paper

(Fig. 3a and b), and averaged 1047.8 mm and 70 d, which accounted for 57.8 and 42.5% of their annual cumulants, respectively. Thus, the rain condition was an important factor that led to higher Fw(DON) in the application period (Fig. 3a, b and e). Fig. 2 shows that the predominant wind direction is from north-northwest to north during the two months (November and December) and southeast-east to east in June, mostly maintaining the very consistent layouts of pig farms in the study site. Thus, the wind from the two pig farms in the direction of north-northwest to north and one in the direction of southeast-east brought more DON compounds, which was another factor to initiate higher Fw(DON) in the three months (June, November and December).

3.2

Annual variations

In the study farmland region, annual Fw(DON) ranged from 5.7 to 71.6 kg N ha1 with average values of 19.7 kg N ha1 during the eight-year period (Table 2), which approached 23.4 kg N ha1 year1 in an adjacent farmland ecosystem of Eastern China,3 higher than 10.1 kg N ha1 year1 in Central Japan29 and even higher than 1.2 to 5.7 kg N ha1 year1 in Central, Western and North China.3,30,31 It was also higher than 5.2 to 11.5 kg N ha1 year1 in adjacent forest ecosystems32–34 and similar to 17.8 kg N ha1 year1 in Dinghushan Biosphere Reserve of Guangdong province, one of greatest economical centers in China with heavy air N pollution.35,36 The results above suggested that DON wet deposition was an important part of TDN and would play a role in N balance of agricultural regions in southern China. Table 2 also shows that annual Cw(DON) ranges from 0.20 to 1.15 mg N L1 and averages 1.2 mg N L1 during 2005–2012, which is slightly higher than 0.8 to 1.5 mg N L1 in the adjacent terrestrial ecosystems of China.34–37 Both Cw(DON) and Fw(DON) in 2006 were signicantly higher than other seven years though there were not the maximum rainfall and rain frequency in 2006, indicating that there was another important factor for DON wet deposition in the red soil agroecosystem. Fig. 4 shows that annual Fw(DON) has a signicantly positive correlation with the usage of pig manure. Organic fertilizers of 600 and 300 kg N pig manure were additionally applied in the study region in 2006 and 2007, which led to the highest Fw(DON) and Cw(DON) in 2006 and higher values in 2007, respectively (Table 2). The results above indicated that application of pig manure was the main factor for DON wet deposition, which was in good agreement with the referring result.11 During 2005 to 2012, annual contributions of DON to DIN varied from 16.8 to 169.5%, whereas those of DON to TDN ranged from 13.2 to 64.8% (Table 2), indicating that DON is an important contributor to N deposition in the red soil farmland ecosystem again. Table 2 also shows that DON accounts for 34.6% of their TDN wet deposition on average, approaching that in the adjacent agroecosystem (31.5% (ref. 37)) and forest ecosystem (40% (ref. 36)) but higher than that in northern China (23–28% (ref. 11 and 31)). Moreover, the average contribution (34.6%) was also in the range of 23–41% in other regions, such as North America, Southeast Asia and Europe



(23%).13 Otherwise, the largest contribution of DON to TDN was found in 2006 when a similar phenomenon was found in the contribution of NH4+–N to DIN due to pig manure being applied in the study region on April 28th 2006, August 25th 2006,6 suggesting pig manure was the possible source of DON again. According to Table 2, DIN wet deposition was in the range of 26.4–39.0 kg N ha1 year1 and averaged 29.6 kg N ha1 year1. This is far higher than 2.2 to 2.9 kg N ha1 year1 measured at two background sites located in remote areas.38,39 It is also much higher than an average value estimated previously for the whole of China in a mapping exercise (Table 3), and was approximately 6-times greater than the values reported by CASTNET, EMEP and EANET.47 However, Fw(DON) in this study was similar to those in other regional agroecosystems of China, such as Beijing, Jiangsu and Henan province, and lower than that in Shanghai with high N pollution (Table 3). In turn, TDN wet deposition arrived 39.1 kg N ha1 year1 on average during the study years excluding the two years (2006 and 2007) when additional pig manure was applied in the study region. When dry N deposition was taken into account and assuming that dry deposition is 25 to 100% of wet deposition,5,7,35,48 the bulk N deposition (dry + wet N deposition) may approach 48.9 to 78.2 kg N ha1 year1, similar to that in the terrestrial ecosystem of northern China (60.6 kg N ha1 year1 (ref. 7)) and that in the adjacent forest ecosystem (49.5 kg N ha1 year1 (ref. 36)), but further exceeded the critical loads of N deposition in southern China (40 kg N ha1 year1 (ref. 49)). The results above suggest that DIN deposition cannot be used alone to determine TDN wet deposition, because TDN wet deposition may be underestimated if DON is not considered. Such high N deposition in the study area indicates that regional N deposition has been intensively inuenced by human activities, particularly agricultural activities such as tillage and fertilization, especially pig manure. Consequently, N deposition should be taken into account when calculating N fertilizer requirements of crops in the study area and its vicinity. And the regional red soil agricultural ecosystem and its vicinity have been susceptible to being affected by these stresses.

3.3

Relations of DON, NH4+–N, NO3–N and TDN

Although shis in the sources of atmospheric N have been reported for NH4+–N and NO3–N in Asian countries that have multiple diffuse sources,42,50 little attention has been paid to DON sources.51 The annual contribution of DON to TDN was 34.6% during the period of study, which also indicated that identifying the source of DON was critical to understanding of local N cycles. Statistically signicant, positive linear regressions between monthly Cw(DON) and Cw(NH4+–N), Cw(DON) and Cw(TDN) were observed (Fig. 5a and c). There was also positive linear regression between monthly Cw(DON) and Cw(NO3–N), but no signicant correlation was observed (Fig. 5b). The results above suggested that the origin of DON was more closely related to NH4+–N than to NO3–N. i.e. to reduced rather than oxidised organic N compounds, which was in good agreement with other regional reports in China.11,14 Zhao et al.52 found NH4+–N and DON loss accounted for 38 and Environ. Sci.: Processes Impacts, 2014, 16, 1050–1058 | 1055

View Article Online



59% of TDN loss of pig manure composting, which also suggested that pig manure was an important source of DON deposition. Hence application of pig manure was the main source of DON deposition in the red soil agro-ecosystem.

4. Conclusion DON wet deposition uxes ranged from 5.7 to 71.6 kg N ha1 year1, with an average value of 19.7 kg N ha1 year1, accounting for 34.6% of TDN. There was a signicant positive relation between annual DON ux and usage of pig manure and about 600 kg N pig manure applied led to the highest DON ux. The origin of DON was more closely related to NH4+–N than to NO3–N. i.e. to reduced rather than oxidised organic N compounds. Our results revealed that: (1) DON deposition showed the higher degree of annual variability, and so longterm monitoring was needed. (2) DON was a signicant part of deposited TDN and agricultural activities, especially applications of organic fertilizers and pig production were the main sources of DON. Further research such as direct measurements of DON species emitted from pig manures is required to conrm our ndings and better understand the effects of DON deposition on the red soil farmland ecosystem.

Acknowledgements This work was supported by the National Natural Science Fund of China (41201206, 41273102), the National Key Technology Research and Development Program of China (2011BAD41B01) and the Key Project of National Natural Science Fund of China (41030751). Thanks are given to the Chinese Ecosystem Research Network, especially to Benhua Chen and Youjun Guan employed in the YTS for their help in collecting the samples.

References 1 J. N. Galloway, F. J. Dentener, D. G. Capone, E. W. Boyer, R. W. Howarth, A. P. Seitzinger, G. P. Asner, C. C. Cleveland, P. A. Gree, E. A. Holland, D. M. Karl, A. F. Michaels, J. H. Porter, A. R. Townsend and C. J. Vorosmarty, Nitrogen cycle: Past, present and future, Biogeochemistry, 2004, 70, 153–226. 2 L. Rodr´ıguez and F. Mac´ıas, Eutrophication trends in forest soils in Golicia (NW Spain) caused by the atmospheric deposition of nitrogen compounds, Chemosphere, 2006, 63, 1598–1609. 3 X. J. Liu, Y. Zhang, W. X. Han, A. Tang, J. L. Shen, Z. L. Cui, P. Vitousek, J. W. Erisman, K. Goulding, P. Christie, A. Fangmeier and F. S. Zhang, Enhanced nitrogen deposition over China, Nature, 2013, 494, 459–462. 4 S. C. Pryor, R. J. Barthelmie and M. Carreiro, Nitrogen deposition to and cycling in a deciduous forest. In: Optimizing Nitrogen Management in Food and Energy Production and Environmental Protection: Proceeding of the 2nd International Nitrogen Conference on Science and Policy, Sci. World, 2001, 1(S2), 245–254.


Paper

5 J. Cui, J. Zhou, H. Yang, J. N. Liang and X. L. Liu, Quantitative input of atmospheric nitrogen to an agro-ecosystem in a typical red soil region, Environ. Sci., 2009, 30(8), 2221–2226. 6 J. Cui, J. Zhou, Y. Peng, Y. Q. He and A. Chan, Atmospheric inorganic nitrogen in wet deposition to a red soil farmland in southeast China, Plant Soil, 2012, 359, 387–395. 7 Y. P. Pan, Y. S. Wang, G. O. Tang and D. Wu, Wet and dry deposition of atmospheric nitrogen at ten sites in Northern China, Atmos. Chem. Phys., 2012, 12, 6515–6535. 8 G. K. Phoenix, W. K. Hicks, S. Cinderby, J. C. I. Kuylenstierna, W. D. Stock, F. J. Dentener, K. E. Giller, A. T. Austin, R. D. B. Lefroy, B. S. Gimeno, M. R. Ashmore and P. Ineson, Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts, Global Change Biol., 2006, 12, 470–476. 9 J. N. Cape, S. E. Cornell, T. D. Jickells and E. Nemitz, Organic nitrogen in the atmosphere – Where does it come from? A review of sources and methods, Atmos. Res., 2011, 102(1–2), 30–48. 10 S. Cornell, Atmospheric nitrogen deposition revisiting the question of the invisible organic fraction, Procedia Environ. Sci., 2011, 6, 96–103. 11 Y. Zhang, L. Song, X. J. Liu, W. Q. Li, S. H. Lv, L. X. Zheng, Z. C. Bai, G. Y. Cai and F. S. Zhang, Atmospheric organic nitrogen deposition in China, Atmos. Environ., 2012, 46, 195–204. 12 J. C. Neff, E. A. Holland, F. J. Dentener, W. H. McDowell and K. M. Russell, The origin, composition and rates of organic nitrogen deposition: a missing piece of the nitrogen cycle?, Biogeochemistry, 2002, 57/58, 99–136. 13 S. Cornell, T. D. Jickells, J. N. Cape, A. P. Rowland and R. A. Duce, Organic nitrogen deposition on land and coastal environments: a review of methods and data, Atmos. Environ., 2003, 37, 2173–2191. 14 J. Li, Y. T. Fang, M. Yoh, X. M. Wang, Z. Y. Wu, Y. W. Kuang and D. Z. Wen, Organic nitrogen deposition in precipitation in metropolitan Guangzhou city, Atmos. Res., 2012, 113, 57–67. 15 J. H. Shi, H. W. Gao and J. Zhang, Atmospheric organic nitrogen deposition and signicance in marine ecosystem, Adv. Earth Sci., 2006, 21(7), 721–729. 16 C. Q. L¨ u, H. Q. Tian and Y. Huang, Ecological effects of increased nitrogen deposition in terrestrial ecosystems, J. Plant Ecol., 2007, 31(2), 205–218. 17 X. J. Liu, L. Duan, J. M. Mo, E. Z. Du, J. L. Shen, X. K. Lu, Y. Zhang, X. B. Zhou, C. N. He and F. S. Zhang, Nitrogen deposition and its ecological impact in China: An overview, Environ. Pollut., 2011, 159, 2251–2264. 18 C. Y. Du, G. M. Zeng, G. Zhang, L. Tang, X. D. Li, D. L. Huang, L. Huang and Y. M. Jiang, Input-output budgets for inorganic nitrogen under acid rain in a subtropical evergreen mixed forest in central-south China, Water, Air, Soil Pollut., 2008, 190(1–4), 1171–1181. 19 V. C. Baliger, N. K. Fageria, H. Eswaran, M. J. Wilson and Z. L. He, Nature and properties of red soils of the world, in The red soils of China: their nature, management and utilization, ed. M. J. Wilson, Z. L. He and X. E. Yang,


View Article Online

Paper


20

21

22

23

24

25

26

27

28 29

30

31

32

33

Kluwer Academic Publishers, The Netherlands, 2004, pp. 7– 27. Z. L. He, X. E. Yang and V. C. Baligar, Increasing nutrient utilization and crop production in the red soil regions of China, Commun. Soil Sci. Plant Anal., 2001, 32(7–8), 1251– 1263. B. H. Sun, Z. Y. Hu, J. L. Lv, L. N. Zhou and C. K. Xu, Dynamic changes of wet nitrogen deposition in a typical hilly agricultural area in Yingtan, Jiangxi, J. Northwest Sci-Tech University of Agriculture and Forestry, 2006, 34(10), 118–192. K. A. Anderson and J. A. Downing, Dry and wet atmospheric deposition of nitrogen, phosphorus and silicon in an agricultural region, Water, Air, Soil Pollut., 2006, 176, 351– 374. T. J. Wang, Q. Liu, H. Zhao, J. Zhou and J. L. Fan, Atmospheric nitrogen deposition in agrecosystem in red soil region of Jiangxi province, Acta Pedologica Sin., 2008, 45(2), 280–287. W. C. Keene, J. A. Montag, J. R. Maben, M. Southwell, J. Leonard, T. M. Church, J. L. Moody and J. N. Galloway, Organic nitrogen in precipitation over Eastern North America, Atmos. Environ., 2002, 36, 4529–4540. M. L. Cabrera and M. H. Beare, Alkaline persulfate oxidation for determining total nitrogen in microbial biomass extracts, Soil Sci. Soc. Am. J., 1993, 57, 1007–1012. P. Huang, J. B. Zhang, A. N. Zhu, X. L. Xin, C. Z. Zhang and D. H. Ma, Atmospheric deposition as an important nitrogen load to a typical agroecosystem in the Huang-Huai-Hai Plain. 1. Measurement and preliminary results, Atmos. Environ., 2011, 45, 3400–3405. Soil physical and chemical analysis and description of soil proles, ed. G. S. Liu, N. H. Jiang and L. D. Zhang, Standards Press of China, Beijing, 1996. R. K. Lu, Analysis methods in soil agrochemistry, Agricultural Science Press, Beijing, 2000, pp. 129–133. Y. Ham and S. Tamiya, Contribution of dissolved organic nitrogen deposition to total dissolved nitrogen deposition under intensive agricultural activities, Water, Air, Soil Pollut., 2006, 178, 5–13. J. L. Shen, Y. Li, X. J. Liu, X. S. Luo, H. Tang, Y. Z. Zhang and J. S. Wu, Atmospheric dry and wet nitrogen deposition on three contrasting land use types of an agricultural catchment in subtropical central China, Atmos. Environ., 2013, 67, 415–424. C. M. Jiang, W. T. Yu, Q. Ma, Y. G. Xu, H. Zou, S. C. Zhang and W. P. Sheng, Atmospheric organic nitrogen deposition: Analysis of nationwide data and a case study in Northeast China, Environ. Pollut., 2013, 182, 430–436. H. B. King, C. P. Liu, Y. J. Hsia and J. L. Hong, Interactions of the Fushan hardwood forest ecosystem and the water chemistry of precipitation, Taiwan J. For. Sci., 2003, 18(4), 363–373. D. L. Tian, W. H. Xiang and W. H. Yang, Nutrient characteristics of hydrological process in yong second rotation Chinese r plantations, Acta Ecol. Sin., 2002, 22(6), 859–865.



34 E. P. Liu, G. S. Liu and J. J. Lei, Study on wet deposition of atmospheric nitrogen in orchard ecosystem of northern Fujian, Acta Agri. Jiangxi, 2012, 24(7), 115–117. 35 Y. T. Fang, P. Gundersen, R. D. Vogt, K. Koba, F. S. Chen, X. Y. Chen and M. Yoh, Atmospheric deposition and leaching of nitrogen in Chinese forest ecosystems, J. Forest Res., 2011, 16(5), 341–350. 36 Y. T. Fang, P. Gundersen, J. M. Mo and W. X. Zhu, Input and output of dissolved organic and inorganic nitrogen in subtropical forests of South China under high air pollution, Biogeosciences, 2008, 5, 339–352. 37 X. Z. Zheng, Y. S. Zhang, H. Ding and J. N. Chen, Nitrogen wet-deposition in agro-ecosystem of northwestern Fujian province, J. Soil Water Conserv., 2012, 26(3), 127–130. 38 J. Tang, H. S. Xue, H. B. Cheng, X. B. Xu, X. C. Zhang and J. Ji, The preliminary study on chemical characteristics of precipitation at Mt. Waliguan, Acta Sci. Cricums, 2000, 20, 420–425. 39 J. Y. Jia, Y. Zhang, X. B. Cai and X. J. Liu, A dynamic changes of wet deposition of nitrogen in southeast Tibet: taking Linzhi experiment station as an example, Acta Ecol. Sin., 2009, 29, 1907–1913. 40 C. Q. Lv, H. Q. Tian and Y. Huang, Ecological effects of increased nitrogen deposition in terrestrial ecosystems, J. Plant Ecol., 2007, 31(2), 205–218. 41 X. Y. Mei and X. F. Zhang, Nitrogen in the atmospheric wet deposition and its effects in agro-ecosystems of Shanghai region, Chin. J. Eco-Agric., 2007, 15(1), 16–18. 42 X. J. Liu, X. T. Ju, Y. Zhang, C. He, J. Kopsch and F. S. Zhang, Nitrogen deposition in agroecosystems in the Beijing area, Agric. Ecosyst. Environ., 2006, 113, 370– 377. 43 Y. X. Xie, Z. Q. Xiong, G. X. Xing, X. Y. Yan, S. L. Shi, G. Q. Sun and Z. L. Zhu, Source of nitrogen in wet deposition to a rice agroecosystem at Tai lake region, Atmos. Environ., 2008, 42, 5182–5192. 44 R. Yang, K. Hayashi, B. Zhu, F. Y. Li and X. Y. Yan, Atmospheric NH3 and NO2 concentration and nitrogen deposition in an agricultural catchment of Eastern China, Sci. Total Environ., 2010, 408, 4624–4632. 45 Y. Wei, Y. A. Tong, M. Duan, L. Qiao, H. W. Tian, X. Y. Lei and W. J. Ma, Atmospheric dry and wet nitrogen in typical agricultural areas of North Shanxi, Chin. J. Appl. Ecol., 2010, 21(1), 255–259. 46 Y. Wei, Y. A. Tong, L. Qiao, X. J. Liu, M. Duan and J. Li, Preliminary estimate of the atmospheric nitrogen in different ecological regions of Shanxi Province, J. AgroEnviron. Sci., 2010, 29(4), 795–800. 47 T. Endo, H. Yagoh, K. Sato, K. Matsuda, K. Hayashi, I. Noguchi and K. Sawada, Regional characteristics of dry deposition of sulfur and nitrogen compounds at EANET sites in Japan from 2003 to 2008, Atmos. Environ., 2010, 45, 1259–1267. 48 L. Granat, Principles in network design for precipitation chemistry measurements, in First Specialty Symp. On Atmospheric Contribution to the Chemistry of Lake Water, ed. D. H. Matheson and F.C. Elder, Int. Assoc. Great Lakes


View Article Online



Res. Supplement 1, State University College, Buffalo, 1976, pp. 65–81. 49 J. Y. Kim, Y. S. Ghim, S. B. Lee, K. C. Moon, S. G. Shim, G. N. Bae and S. C. Yoon, Atmospheric deposition of nitrogen and sulfur in the Yellow Sea region: Signicance of long-range transport in East Asia, Water, Air, Soil Pollut., 2009, 205(1–4), 259–272. 50 N. Fukuzaki and H. Hayasaka, Seasonal variations of nitrogen isotopic ratios of ammonium and nitrate in precipitation collected in the Yahiko-Kakuda mountains


Paper

area in Niigata prefecture, Water, Air, Soil Pollut., 2009, 203, 391–397. 51 K. S. Lee, D. S. Lee, S. S. Lim, J. H. Kwak, B. J. Jeon, S. I. Lee, S. M. Lee and W. J. Choi, Nitrogen isotope ratios of dissolved organic nitrogen in wet precipitation in a metropolis surrounded by agricultural areas in southern Korea, Agric. Ecosyst. Environ., 2012, 159, 161–169. 52 Q. Zhao, M. Y. Zhang, Y. Liu, D. Wu and S. P. Yang, Study on the nitrogen transforming regulation during the pig dung compost, Heilongjiang Agri. Sci., 2008, 2, 58–60.


Contribution of atmospheric nitrogen deposition to diffuse pollution in a typical hilly red soil catchment in southern China.

A Review of Spatial Variation of Inorganic Nitrogen (N) Wet Deposition in China.

Inorganic nitrogen wet deposition: Evidence from the North-South Transect of Eastern China.

Composition of dissolved organic nitrogen in rivers associated with wetlands.

Impacts of Cropping Systems on Aggregates Associated Organic Carbon and Nitrogen in a Semiarid Highland Agroecosystem.

Refractory dissolved organic nitrogen accumulation in high-elevation lakes.

Sinks for inorganic nitrogen deposition in forest ecosystems with low and high nitrogen deposition in China.

Reduced nitrogen dominated nitrogen deposition in the United States, but its contribution to nitrogen deposition in China decreased.

CAN Canopy Addition of Nitrogen Better Illustrate the Effect of Atmospheric Nitrogen Deposition on Forest Ecosystem?

Long-term atmospheric deposition of nitrogen, phosphorus and sulfate in a large oligotrophic lake.

Reply to Sun et al.: Deposition of organic nitrogen.

Nitrogen deposition enhances carbon sequestration by plantations in northern China.

Decreased atmospheric sulfur deposition across the Southeastern U.S.: when will watersheds release stored sulfate?

Inorganic nitrogen supply and dissolved organic nitrogen abundance across the US Great Plains.

A global assessment of forest surface albedo and its relationships with climate and atmospheric nitrogen deposition.

Dissolved organic nitrogen and its biodegradable portion in a water treatment plant with ozone oxidation.

Formation and removal of dissolved organic nitrogen (DON) in membrane bioreactor and conventional activated sludge processes.

Deposition of semivolatile organic compounds to spruce needles : I. Calculation of dry and wet fluxes.

Relationship between the concentrations of dissolved organic matter and polycyclic aromatic hydrocarbons in a typical U.K. upland stream.

Changes in the dissolved organic matter leaching from soil under severe temperature and N-deposition.

Deposition of semivolatile organic compounds to spruce needles : I. Calculation of dry and wet fluxes.

Total nitrogen concentrations in surface water of typical agro- and forest ecosystems in China, 2004-2009.

Conditional vulnerability of plant diversity to atmospheric nitrogen deposition across the United States.

Characteristics of nitrogen loading and its influencing factors in several typical agricultural watersheds of subtropical China.