Environmental impacts and resource use of milk production on the North China Plain, based on life cycle assessment

Xiaoqin Wang; Stewart Ledgard; Jiafa Luo; Yongqin Guo; Zhanqin Zhao; Liang Guo; Song Liu; Nannan Zhang; Xueqin Duan; Lin Ma

doi:10.1016/j.scitotenv.2017.12.259

Environmental impacts and resource use of milk production on the North China Plain, based on life cycle assessment

Sci Total Environ. 2018 Jun 1:625:486-495. doi: 10.1016/j.scitotenv.2017.12.259. Epub 2017 Dec 29.

Authors

Xiaoqin Wang¹, Stewart Ledgard², Jiafa Luo², Yongqin Guo³, Zhanqin Zhao³, Liang Guo⁴, Song Liu⁴, Nannan Zhang³, Xueqin Duan⁴, Lin Ma⁵

Affiliations

¹ College of Natural Resources and Environment, Northwest Agriculture and Forestry University, Yangling 712100, China. Electronic address: xqwang@nwsuaf.edu.cn.
² AgResearch, Ruakura Research Centre, Hamilton 3240, New Zealand.
³ Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, The Chinese Academy of Sciences, Shijiazhuang 050021, Hebei, China.
⁴ College of Natural Resources and Environment, Northwest Agriculture and Forestry University, Yangling 712100, China.
⁵ Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, The Chinese Academy of Sciences, Shijiazhuang 050021, Hebei, China. Electronic address: malin1979@sjziam.ac.cn.

PMID: 29291563
DOI: 10.1016/j.scitotenv.2017.12.259

Abstract

Life cycle assessment methodology was used to quantify the environmental impacts and resource use of milk production on the North China Plain, the largest milk production area in China. Variation in environmental burden caused by cow productivity was evaluated, as well as scenario analysis of the effects of improvement practices. The results indicated that the average environmental impact potential and resource use for producing 1kg of fat and protein corrected milk was 1.34kgCO₂eq., 9.27gPO₄^3-eq., 19.5gSO₂eq., 4.91MJ, 1.83m² and 266L for global warming potential (GWP), eutrophication potential (EP), acidification potential (AP), non-renewable energy use (NREU), land use (LU) and blue water use (BWU; i.e. water withdrawal), respectively. Feed production was a significant determinant of GWP, NREU, LU and BWU, while AP and EP were mainly affected by manure management. Scenario analysis showed that reducing use of concentrates and substituting with alfalfa hay decreased GWP, EP, AP, NREU and LU (by 1.0%-5.5%), but caused a significant increase of BWU (by 17.2%). Using imported soybean instead of locally-grown soybean decreased LU by 2.6%, but significantly increased GWP and NREU by 20% and 6.9%, respectively. There was no single perfect manure management system, with variable effects from different management practices. The environmental burden shifting observed in this study illustrates the importance of assessing a wide range of impact categories instead of single or limited indicators for formulating environmental policies, and the necessity of combining multiple measures to decrease the environmental burden. For the North China Plain, improving milking cow productivity and herd structure (i.e. increased proportion of milking cows), combining various manure management systems, and encouraging dairy farmers to return manure to nearby crop lands are promising measures to decrease multiple environmental impacts.

Keywords: Acidification; Dairy; Eutrophication; Feed strategy; Global warming; Manure management.

MeSH terms

Animals
Cattle
China
Dairying*
Environment*
Female
Global Warming*
Manure
Milk

Substances

Manure