Aggravation of nitrogen losses driven by agriculture and livestock farming development on the Qinghai-Tibet Plateau. (15th January 2023)

• Record Type: Journal Article
• Authors: Wang, Fangfang; Liu, Shiliang; Liu, Hua; Liu, Yixuan; Yu, Lu; Wang, Qingbo; Dong, Yuhong; Sun, Jian; Tran, Lam-Son Phan; Li, Weiqiang
• Is Part Of: Journal of environmental management. Volume 326:Part B(2023)
• Publication Date: 2023-01-15
• Subjects: N losses -- Agriculture and livestock husbandry -- Crop-livestock systems -- Driving force -- Qinghai-tibet plateau; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.116795
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Nitrogen (N) losses from crop-livestock production is a major threat to the environment and human health at regional, national and global scales. A comprehensive understanding of the sources, spatiotemporal distribution and drivers of N losses is of great significance for mitigating its negative impacts and promoting N sustainable management. Here, we used the county-scale N flow model to quantitatively analyze the N losses and their driving forces of crop-livestock production on the Qinghai-Tibet Plateau (QTP). Between 2000 and 2018, the total N losses increased for more than 79% of counties on the QTP. The hotspot areas accounted for over 80% of total N losses, expanding from the east and south to the north and west of the QTP. NH3 was the main source of atmospheric N losses (over 80%) while the direct discharge of manure was the main source of water N losses. Structural equation modeling (SEM) showed that chemical fertilizer caused the largest driving effect on atmospheric N losses, and the total output value of agriculture and forestry was the main driver of water N losses. Uneven distribution of crop production and livestock contributed to the aggravation of N losses. Over 70% of counties had grater manure N excretion than crops could take up, and large proportion of manure could not be returned to the field. More than 90% of the counties used grater amount of chemical fertilizer N than crops could take up, indicating that livestock manure has not yet fully replaced chemical fertilizer N. The results provide effective guidance and support for N utilization and management of livestock in agricultural and pastoral areas. Highlights: N losses on the Qinghai-Tibet Plateau was first quantified at county scale. Most hotspots were found in the NH and the HDMZ in 2000 and 2018. NH3 and direct discharge of manure were the main source to the N losses. Chemical fertilizer and agricultural output value were the main drivers of N losses. Uneven distribution of crop production and livestock also contributed to N losses.