EVALUATION OF GREENHOUSE GAS EMISSIONS FROM THREE CONTRASTING INTEGRATED CROP AND LIVESTOCK PRODUCTION SYSTEMS DURING 1991-2016 IN GANSU OF CHINA

Abstract

Agricultural production is an important source of greenhouse gas (GHG) emissions, which in general accounts for 10-12% of the global anthropogenic GHG emissions (Herreroet al., 2011; Pishgar-Komlehet al., 2013; Bell et al., 2014). Methane (CH4) and nitrous oxide (N2O) are main GHG emission sources in the agricultural production sector, for example, CH4 and N2O emissions in China account for 50% and 92% of national total emissions, respectively (Donget al., 2013). In China, total GHG emissions from agriculture production grew rapidly from 605 Mt CO2-equivelant (CO2-eq) in 1994 to 686 Mt CO2-eq in 2007, and increased by approximately 80Mt per year since 2010 (Chen and Zhang 2010; Dong et al., 2013). There is evidence indicating that the effect on atmospheric temperature derived by climate change has impacted crop production and water use efficiencies in China (Dong et al., 2013; Guoet al., 2010). Chinese government made commitments in the UN Climate Change Conference in 2009 to reduce carbon emissions per unit gross domestic product by 40-50% in 2020 (Chenget al., 2011). Therefore, there is an urgent need to provide detailed information on GHG emissions from crop and livestock production in different region of China, where the agricultural production systems are influenced by climate and other environmental factors. However, there is little information available on the accurate calculation of GHG emissions from agricultural production systems in Northwest China. The lack of such information could impact policy makers and agricultural industries to make informed decisions for mitigation of GHG emissions from agricultural production. Agricultural production systems in China vary greatly in different regions, mainly due to the variations in climate, landscape and other environmental conditions. Even within Gansu Province, a region located in the centre of Northwest China, agricultural activities are commonly categorised in four contrasting areas: Loess Plateau, Hexi Oasis, Qinling Bashan Mountains and Tibet Plateau, mainly according to the climate variation (Renet al., 2009). The detailed information for the first three regions is presented in Table 1. The objectives of the present study were to evaluate the regional differences (Loess Plateau vs. Hexi Oasis vs. Qinling Bashan Mountains) in Gansu Province in GHG emission factors associated with producing per unit of crop and livestock Pak. J. Agri. Sci., Vol. 56(2), 469-480; 2019 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/19.6147 http://www.pakjas.com.pk