Dinitrogen (N2) fixation is widely recognized as an important

Given the intensity of agriculture and the position of environmental degradation in the country it is necessary to strike balance between fertilizer use and developmental goals for the achievement of economic and environment sustainability. The development could be possible only through judicious management of natural resources without losing much on the pace of the present development.

The International Maritime Organization recently revised the MARPOL Annex VI so regulations are clearer and nitrogen oxides emissions are further reduced.

Here the authors present results of the first multi-decadal experiment to examine the impacts of chronic, experimental nitrogen addition above ambient atmospheric nitrogen deposition. This total input rate is comparable to terrestrial nitrogen deposition in many industrialized nations. The researchers found that this chronic low-level nitrogen addition rate reduced plant species numbers by 17% relative to controls receiving ambient N deposition.

Nitrates enter human body through drinking water, food and air. Ingested nitrates converted to nitrite by microflora lead to methaemoglobinemia, increased free oxide radicals that predispose cells to irreversible damage and effects like cancer, increased infant mortality, abortions, birth defects, recurrent diarrhoea, recurrent stomatitis, histopathological changes in cardiac muscles, alveoli of lungs and adrenal glands, deterioration of immune system of the body.

During the past century through food and energy production, human activities have altered the world's nitrogen cycle by accelerating the rate of reactive nitrogen creation. India has made impressive strides in the agricultural front, in which N fertilizer plays a major role.

Anthropogenic activities are responsible for the enhanced emission of reactive nitrogenous species like nitrous oxide (N2O), oxides of nitrogen (NOx) and ammonia (NH3) into the atmosphere from the biosphere. This article reviews the available estimates of emissions of these reactive nitrogenous species for India.

The coastal and marine nitrogen cycle occupies a complex, central role within the biogeochemical cycles. Human interventions in the earth system have risen to unprecedented levels, strongly influencing the global nitrogen cycle. The nitrogen cycle in the open ocean compared to coastal ecosystems appears to have remained unharmed, although recent observations have shown increasing anthropogenic influence.

The South Asian rivers show a discharge weighted average NO3-N of 2 mg/l and average sediment-bound N, that is mostly organic, of 0.2%. The reported global average for the uncontaminated river system is of the order of about 0.028 mg/l (NO3-N). Hence, our freshwater aquatic systems can no longer be considered natural, at least with respect to nitrogen transport.