High nitrate accumulation in the Vadose Zone after land-use change from croplands to orchards

Gao, Jingbo; Wang, Shimao; Li, Zhiqin; Wang, Lei; Chen, Zhujun; Zhou, Jianbin. 2021 High nitrate accumulation in the Vadose Zone after land-use change from croplands to orchards. Environmental Science & Technology, 55 (9). 5782-5790. https://doi.org/10.1021/acs.est.0c06730

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Official URL: http://dx.doi.org/10.1021/acs.est.0c06730

Abstract/Summary

Additional evidence indicates that the nitrate stored in the deep soil profile has an important role in regulating the global nitrogen (N) cycle. This study assessed the effects of land-use changes from croplands to intensive orchards (LUCO) on N surplus, nitrate accumulation in deep soil, and groundwater quality in the kiwifruit belt of the northern slope region of the Qinling Mountains, China. LUCO resulted in comparatively high N surplus in orchards (282 vs 1206 kg ha–1 yr–1, respectively). The average nitrate accumulation within the 0–10 m profiles of orchards was 7113 kg N ha–1, which was equal to approximately the total N surplus of 6 years of the orchards. The total nitrate stock within 0–10 m soil profiles of the kiwifruit belt was 266.5 Gg N, which was 3.5 times higher than the total annual N input. The nitrate concentrations of 97% of groundwater samples exceeded the WHO standard. The LUCO resulted in large nitrate storage in the vadose zone and caused serious contamination of groundwater. Our study highlights that nitrate accumulation in the vadose zone of an intensive land-use system is one of the main fates of surplus N and also a hotspot of nitrate accumulation.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1021/acs.est.0c06730
ISSN:	0013-936X
Additional Keywords:	GroundwaterBGS, Groundwater
Date made live:	27 Jul 2021 10:30 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/530798

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1021/acs.est.0c06730

ISSN:

0013-936X

Additional Keywords:

GroundwaterBGS, Groundwater

Date made live:

27 Jul 2021 10:30 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/530798