关键词: 氮素形态, 专用型小麦, 根系, 氮素利用率

Abstract: Ecological footprint (EF), as a kind of biophysical indicator in measuring the humanity’s use extent of natural resources, is considered as one of the
 most successful methods to assess the sustainable development, and has gained much attention on national and international level since it was first used by Wackernagel and Rees in 1996. Production coefficient is an important parameter in EF model, and directly affects the reliability of the results. In order to make c
omparisons among different regions in China, production coefficient was introduced to relate the regional primary productivities of different land types (i.e.,
cropland, pasture, forest land, and fishing ground) to the integrated average primary biomass productivity of the corresponding land type. Aimed to analyze the
ecological footprint of different areas in regional scale, this paper calculated the production coefficient on national level and provincial level based on the
net primary productivity (NPP) from MODIS data with 1-km resolution in 2001. On national level, the production coefficient of cropland, forest land, pasture, a
nd fishing ground was 1.74, 0.86, 0.51, and 0.74, respectively, which meant that the cropland productivity in China was bigger than the global average one. On provincial level, the production coefficient differed with provinces, because the NPP of different land use types in different regions was varied.

Key words: Nitrogen form, Wheat with specialized end-uses, Root system, N use efficiency