Wet and Dry Atmospheric Depositions of Inorganic Nitrogen during Plant Growing Season in the Coastal Zone of Yellow River Delta

Abstract

The ecological problems caused by dry and wet deposition of atmospheric nitrogen have been widespread concern in the world. In this study, wet and dry atmospheric depositions were monitored in plant growing season in the coastal zone of the Yellow River Delta (YRD) using automatic sampling equipment. The results showed that SO4 2− and Na+ were the predominant anion and cation, respectively, in both wet and dry atmospheric depositions. The total atmospheric nitrogen deposition was ~2264.24 mg m−2, in which dry atmospheric nitrogen deposition was about 32.02%. The highest values of dry and wet atmospheric nitrogen deposition appeared in May and August, respectively. In the studied area, NO3 −–N was the main nitrogen form in dry deposition, while the predominant nitrogen in wet atmospheric deposition was NH4 +–N with ~56.51% of total wet atmospheric nitrogen deposition. The average monthly attribution rate of atmospheric deposition of NO3 −–N and NH4 +–N was ~31.38% and ~20.50% for the contents of NO3 −–N and NH4 +–N in 0–10 cm soil layer, respectively, suggested that the atmospheric nitrogen was one of main sources for soil nitrogen in coastal zone of the YRD.

Five-year changes in soil organic carbon and total nitrogen in coastal wetlands affected by flow-sediment regulation in a Chinese delta

“…The electrical conductivity (EC) and NH 4 + -N contents in the top 10 cm soils were significantly higher in 2007 than those in 2012 ( p < 0.05), but no significant differences in the TN, TN density (TND) and nitrate nitrogen (NO 3 − -N) contents were observed ( p > 0.05). Higher nitrogen deposition levels, i.e., ~2264.24 mg /m 2 in this region 28 29 , might have supplemented the nitrogen loss during the study period. Additionally, a decrease in NH 4 + -N content from 2007 to 2012 ( p < 0.05) might be explained by the fact that plant uptake or ammonia volatilization under medium alkaline environment in this region as well as the conversion to NO 3 − -N through nitrification, although nitrate could be leached into deeper soils 30 31 .…”

Overall supply level, not the relative supply of nitrogen and phosphorus, affects the plant community composition of a supratidal wetland in the Yellow River Delta

“…The Atmospheric nitrogen deposition of the study area is about 2.26 g m −2 in the growing seasons (Yu et al, 2014). Considering nitrogen deposition in non-growing seasons and the input of nitrogen from other sources, we defined 5 g m −2 y −1 as the annual supply of N for low supply level with basic N:P supply ratio (15:1 L).…”

“…The Yellow River Delta wetland, the most extensive early successional wetland ecosystem in China, has significant ecological value due to its important overwintering stopover and breeding function for migrating birds (Li et al, 2019). In recent years, this area is undergoing increasing inputs of N and P caused by atmospheric deposition (Yu et al, 2014), water-sediment regulation (Li et al, 2017) and regional land use change (Yu et al, 2016). However, the response of the plant community to N and P supply situation variations remains unclear.…”

Soil quality assessment of coastal wetlands in the Yellow River Delta of China based on the minimum data set

“…Both NO 3 --N and TN showed significantly higher average levels in spring than in autumn (p<0.05) and slightly lower levels in summer (p>0.05). Higher dry nitrogen deposition in the Yellow River Delta in spring could contribute to elevating N levels in the top 10 cm soils (Yu et al, 2014), and higher wet nitrogen deposition in summer could offset some soil nitrogen loss due to plant assimilation in summer and autumn. Additionally, no significant differences in pH, SOM, AP, TC and TK were observed among the three sampling seasons (p>0.05), suggesting these indicators had no significant seasonal variations in this region.Compared with TFR soils, the average contents of SWC, TK and TS were significantly lower in STFR soils (Table 3, p<0.05) and slightly lower in SFR soils (p>0.05), which could be attributed to tidal flooding of sea water twice a day in the TFR.…”