Spatial variations in soil and plant nitrogen levels caused by ammonia deposition near a cattle feedlot. (March 2018)

• Record Type: Journal Article
• Authors: Shen, Jianlin; Chen, Deli; Bai, Mei; Sun, Jianlei; Lam, Shu Kee; Mosier, Arvin; Liu, Xinliang; Li, Yong
• Is Part Of: Atmospheric environment. Volume 176(2018)
• Page Start: 120
• Page End: 127
• Publication Date: 2018-03
• Subjects: Nitrogen deposition -- Soil nitrogen -- Leaf nitrogen -- Stable isotope 15N; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2017.12.022
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Cattle feedlots are significant ammonia (NH3 ) emission sources, and cause high NH3 deposition. This study was conducted to investigate the responses of soil mineral nitrogen (N), percent cover of plant species, leaf N content, and leaf δ 15 N to NH3 deposition around a 17, 500-head cattle feedlot in Victoria, Australia. Soil samples were collected in May 2015 at 100-m intervals along eight downwind transects, and plant samples were collected in June 2015 from five sites at 50- to 300-m intervals along a grassland transect within 1 km downwind of the feedlot. NH3 deposition was also monitored at five sites within 1 km downwind of the feedlot. The estimated NH3 -N deposition rates ranged from 2.9 kg N ha −1 yr −1 at 1 km from the feedlot to 203 kg N ha −1 yr −1 at 100 m from the feedlot. The soil mineral N content was high (22–98 mg kg −1, mainly nitrate), significantly decreased with increasing distance from the feedlot, and significantly increased with increasing NH3 -N deposition. With increasing NH3 -N deposition, the percent cover of the herb species Cymbonotus lawsonianus increased significantly, but that of the grass species Microlaena stipoides decreased significantly. The leaf total N contents of the grass and herb species were high (>4%), and were linearly, positively correlated with the NH3 -N deposition rate. Leaf δ 15 N values were linearly, negatively correlated with the N deposition rate. These results indicate that the leaf N contents and δ 15 N values of C. lawsonianus and M. stipoides may be bioindicators of N deposition. Highlights: NH3 deposition decreased with distance from a 17, 500-head cattle feedlot. Soil mineral N level was high and decreased with distance from the feedlot. Percent plant cover showed significant variation with distance from the feedlot. Plant leaf N content was linearly, positively correlated with NH3 deposition. Plant leaf δ 15 N value was linearly, negatively correlated with NH3 deposition.