Nitrogen Cycle Sustainability and Sustainable Technologies for Nitrogen Fertilizer and Energy Management

Abstract

Nitrogen (N) is necessary for all forms of life and a crucial component in the increased production of food to feed the continuously increasing human and animal populations. In many ecosystems on land and sea, the supply of nitrogen controls the nature and diversity of plant life, the population dynamics of both grazing animals and their predators, and vital ecological processes such as plant productivity and the cycling of carbon and soil minerals. Since the beginning of the last century, mankind has injected increasing amounts of reactive nitrogen into the environment, intentionally as fertilizer and unintentionally as a by-product of combusting fossil fuels. As a result, nitrogen cycle is being altered causing possible grave impacts on biodiversity, global warming, water quality, human health, and even the rate of population growth in several parts of the world. The key N management technology for sustainable and profitable crop production is the synchronization of N supply with crop demand. Aiming at improving N-use efficiency in high-input cropping systems, the focus should be on higher yield with less fertilizer N. In low-input systems, additional use of N fertilizer may be required to increase yield level and yield stability. Realigning the time and rate of N application with help of modern tools, like SPAD meter, LCC, Green seeker, Simulation modeling, GIS and remote sensing as per spatial-indigenous nutrient supply capacity and temporal variability of soil enhances the synchronization between N supply and plant demand. Site specific N application with balanced fertilization and integration of locally available organic manures further improves the N use efficiencies in cropping system. Sustainable strategies for N management in energy sector are the development of technologies that either increases efficiency of fuel combustion or removes N oxides from the exhaust stream. The complete solutions, however, are closely linked to the development of non-polluting alternative energy sources. Research and development efforts needs to be strengthened to find out more effective technological solutions and try to balance them against cost and efficiency.