Dry deposition of ammonia around paddy fields in the subtropical hilly area in southern China

Yuchen Yi,Chaodong Yang,Jinshui Wu,Jianlin Shen,Juan Wang,Yong Li

doi:10.1080/16742834.2020.1738208

Abstract

This study measured the ammonia (NH3) concentration and dry deposition within 100 m around paddy fields (0.6 ha) with double rice cropping in the subtropical hilly area in southern China, with the ...

Highlights

Ammonia (NH3), which mainly comes from NH3 volatilization from nitrogen (N) fertilizer application in farmland and livestock manure (Kang et al 2016), is the most abundant alkaline gas in the atmosphere
Ammonia and ammonium in the atmosphere can be returned to the surface through wet and dry deposition, which are the main components of atmospheric N deposition, and usually account for more than 50% of the total N deposition (Pan et al 2012; Shen et al 2013; Xu et al 2015)
The results showed that the average concentration of NH3 at 100 m in the downwind area was still high within 15 days after applying basal fertilizer, which was 5.0–5.2 times that at the background site, but it had dropped by 65%–81% compared with that at 0 m

Summary

Introduction

Ammonia (NH3), which mainly comes from NH3 volatilization from nitrogen (N) fertilizer application in farmland and livestock manure (Kang et al 2016), is the most abundant alkaline gas in the atmosphere. Studies on NH3 deposition around animal farms in Europe, America, and Australia have shown that there were high NH3 deposition rates around the sources of NH3 emissions (Fowler et al 1998; Walker et al 2008; Shen et al 2016) Measures such as planting trees around the sources were proposed to increase the near-source deposition of NH3, and to reduce the long-distance transportation of NH3, so as to reduce its environmental hazards (Bealey et al 2016). Paddy and vegetable fields are mainly distributed in the valleys, tea plantations and orchards are distributed in the mountains and hills, and animal farms are often built near the mountains and hills This pattern of distribution of croplands or animal farms accompanying the surrounding natural ecosystems may result in a higher near-source deposition ratio of NH3 in the subtropical hilly region than that in the plain areas. Recent observations showed that the concentration of NH3 in the subtropical hilly areas of China was not very high (Liu et al 2019), which indirectly indicates that there may be a high near-source deposition of NH3 in the subtropical hilly areas, but there is no direct experimental evidence

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Discussion

Conclusion