Abstract
This study was to evaluate the difference in greenhouse gas (GHG) emissions from 3 contrasting integrated crop and livestock
production systems in Gansu of China from 1991 to 2016 using the life cycle assessment technique. The three systems were
located in different regions: Hexi Oasis (dry arid, intensive crop/livestock production), Loess Plateau (semi-arid/semi-humid,
dominated by extensive crop production) and Qinling Bashan Mountains (moist-subtropical, extensive crop/livestock
production). The data used were collated from 525 farms (35 farms/county and 5 counties/region) thorough official statistical
records and farm survey. The ANOVA analysis of average data from 2012 to 2016 indicated that Loess Plateau had a higher
CO2 equivalent (CO2-eq) emission factor per kg DM product of maize and flaxseed than other 2 regions (P< 0.05), while a
lower rate per kg beef carcass weight. Qinling Bashan Mountains had a lower emission factor for producing 1 ¥ of crop products
than other 2 regions (P< 0.05). The evaluation of change in GHG emissions from 1991 to 2016 indicated that CO2-eq per kg
carcass of pork, beef, and lamb in the 3 production systems generally declined during this period, but emissions per kg DM of
potato, rapeseed, and maize increased. However, CO2-eq per ¥ of crop and livestock products tended to decrease from 1991 to
2016, driven mainly by market price and productivity. The present results provide the benchmark information for local policy
makers and agricultural industries to make informed decisions for mitigation of GHG emissions from agricultural production
in Gansu of China.
