LONG-TERM NITROGEN BUDGETS FOR INDIAN AGRICULTURAL LANDSCAPES

Abstract

Established methodology to estimate the Net Anthropogenic Nitrogen Input (NANI) is applied to India at district scale from the year 1966 to 2017. In other words, NANI refers to the amount of nitrogen that is added to the environment due to human activities like fertilizer application, atmospheric deposition of oxidised N due to fossil fuel burning and crop burning and crop production. ICRISAT datasets are utilized to calculate the components of NANI using the software’s like MS-Excel, Arc-GIS and R-Studio. Among all the components of NANI, fertilizer consumption is the highest contributor to NANI followed by agricultural N fixation and NFF. Fertilizer consumption for India is increased to 50% from the year 2000 to 2011 and the major states which are consuming fertilizer at higher rates are Punjab, Haryana, western Uttar Pradesh, Bihar and West Bengal. Atmospheric N deposition is highest in northern states of India because of higher emissions from trucks, automobiles and burning of crop residue. Agricultural N fixation is higher in the central part of India due to the production of N fixing crops like soyabean, groundnut and regionally important crops like chickpea and pigeon pea. NFF is negative for the year 1975, 2011, 2016 and 2017 showing production is higher over consumption. Riverine N flux is calculated from the average linear regression equation obtained which varies from 238 tons N to 727 tons N.