Abstract:

【Objective】Based on the statistic data of cultivated area, sown area, crop yield, production value and farmland investment of the crop production in the period of 1993 to 2012, the dynamics, distributions and compositions of carbon footprint (CF) of the crop production were estimated in North China Plain (NCP), which will provide a theoretical support and scientific basis for the development of low-carbon agriculture. 【Method】Based on the historical statistic data of cultivated area, sown area, crop yield, production value and farmland investment of the crop production of 47 prefecture-level cities in 5 provinces and cities (Hebei, Beijing, Tianjin, Shandong and Henan) in North China Plain, and used the theory of carbon footprint and life cycle assessment method in the agricultural sector, CF per unit sown area (CFs), CF per unit cultivated area (CFc), CF per unit yield (CFy) and CF per unit production value (CFv) of the crop production were estimated in North China Plain. The dynamic and distributions of carbon footprint were analyzed briefly. In addition, the proportions of different agricultural inputs in carbon footprint of crop production were explored.【Result】 CFs and CFc of crop production showed an increasing trend in the last twenty years. The CFs of crop production was 4.08 tCO₂eq·ha^-1 in period I (1993-2002) and 4.72 tCO₂eq·ha^-1in period II (2003-2012), respectively; The CFc of crop production was 6.81 tCO₂eq·ha^-1 in period I (1993-2002) and 8.12 tCO₂eq·ha^-1in period II (2003-2012), respectively. CFy and CFv of crop production showed a decreasing trend in the last twenty years. The CFy of crop production was 0.54 tCO₂eq·t^-1 in period I and 0.42 tCO₂eq·t^-1in period II, respectively. The CFv of crop production was 3.91 tCO₂eq·¥10^-4 in period I and 2.51 tCO₂eq·¥10^-4 in period II, respectively. The carbon footprints were different in different regions of the NCP. Most coastal regions (Tangshan, Tianjin and Yantai, etc.) have bigger CFs and CFc and smaller CFy and CFv. On the contrary, most cities of South Henan (Zhumadian, Xinyang, and Pingdingshan, etc.) have smaller CFs and CFc and bigger CFy and CFv. The agricultural inputs per unit sown area and the vegetable crops sown area percentage in high yield region were significantly higher than that in low yield region, respectively. The results presented here indicated that the main components of carbon footprint were electricity for irrigation (30.25%), N fertilizer (23.07%), and direct emissions of N₂O (19.83%).【Conclusion】In the last twenty years, the CFs and CFc of crop production increased, but the CFy and CFvdecreased in North China Plain. Most coastal regions have bigger CFs and CFc and smaller CFy and CFv, but the regions of southern Henan province were the opposite. In addition, the electricity for irrigation and N fertilizer were the major resources of emissions in North China Plain.

Key words: North China Plain, crop production, carbon intensity, carbon footprint