Net anthropogenic nitrogen input from human activities and its impacts from parameters in Henan Province

In order to explore the characteristics of net nitrogen input of human activities and the influence of its parameters on the estimation results in the main grain producing areas of plain area. The county-level statistical data from 1990 to 2015 in Henan province was collected and the relevant parameters of NANI model were selected and defined. The characteristics of temporal and spatial distribution, change trend and the influence of parameters on the estimation results of NANI were analyzed. The results show that: (1) From 1990 to 2015, the NANI of Henan province showed an increasing trend. The NANI of 1990, 1995, 2000, 2005, 2010 and 2015 were 14347, 19146, 21466, 24251, 23711 and 26156kg/(km2•a), respectively. For spatial variation, the counties with higher NANI were mainly distributed in the central and eastern plain areas, while the counties in the western hilly areas had lower NANI. (2) Among the input components of NANI model, the net nitrogen input of food/feed was the most affected by the parameters. Compared with the calculation and estimation results of selecting appropriate parameters, the variation range of this parameter was-23.1%~71.3%, the variation range of crop nitrogen fixation was -31.2%~41.2%%, and the variation range of fertilizer nitrogen input was -2.8%~4.5%. © 2021, Editorial Board of China Environmental Science. All right reserved.