NAN HA, TIL FEIKE, HANS BACK, ENNO BAHRS
University of Hohenheim, Inst. of Farm Management, Germany
Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Inst. for Strategies and Technology Assessment, Germany
Overuse of nitrogen (N) fertiliser constitutes the major issue of current crop production in China, exerting a substantial effect on global warming through massive emissions of greenhouse gases (GHG). Despite the ongoing efforts, which include the promotion of technologically sophisticated N management schemes, farmers' N rates maintain at excessive rates. Therefore the current study tests two simple and easily to apply N fertiliser recommendation strategies, which could be implemented on large scale through the existing agricultural advisory system of China, at comparatively low cost. Building on a detailed crop production dataset of 65 winter wheat (WW) and summer maize (SM) producing farm households of the North China Plain, scenario analysis is applied. The effects of the two N strategies under constant and changing yield levels on product carbon footprint (PCF) and gross margin (GM) are determined for the production conditions of every individual farm household. The N fixed rate strategy realised a higher improvement potential in PCF and GM in WW and SM. The analysis furthermore revealed that improved N management has a significant positive effect on PCF, but only a marginal and insignificant effect on GM. On the other side, a potential 10% yield loss would have only a marginal effect on PCF, but a detrimental effect on farmers' income. With farmers currently applying excessive N rates as a ``cheap insurance'' against potential N limitations, the agricultural advisory system of China requires fundamental changes to successfully overcome the excessive fertiliser use and respective environmental pollution. The study concludes that the indirect subsidisation of N fertilisers needs to be stopped and a N tax should be introduced. Furthermore a cross compliance system should be implemented, which punishes non-compliance with maximum allowed N rates by cutting direct farm payments.
Keywords: China, fertiliser, GHG mitigation, global warming, gross margin, nitrogen