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.

Nitrogen use efficiency (NUE) in plants is a complex phenomenon that depends on a number of internal and external factors, which include soil nitrogen availability, its uptake and assimilation, photosynthetic carbon and reductant supply, carbon

Safe and sufficient food production is an important issue in India. Development of improved varieties by modern plant breeding is crucial. Nowadays, GM (genetically modified) varieties are emerging as a strong tool and promise.

Cities in the developing countries have multiple modes of human and animal waste treatment and disposal that finally decide the overall impact on the urban ecosystem, and these have been studied for the city of Bangalore. Four modes are found, namely underground sewage systems, decentralized soak pits and septic tanks, open defecation and a miniscule effort at composting. The extent of N released per unit area is high, ranging between 0.44 and 1.4 t ha

The flows of reactive N in terrestrial, aquatic and atmospheric ecosystems in India are being increasingly regulated by inputs, use efficiency and leakages of reactive N from agriculture. In the last three decades, use of reactive N in the form of chemical fertilizers has kept pace with the production of foodgrains, although the consumption is concentrated in certain areas with intensive farming.

Original Source

Reactive nitrogen (Nr) includes the inorganic (NH3, NH4, NOx, HNO3, N2O, NO3) and organic forms (urea, amines, proteins, nucleic acids) that readily participate in various reactions of the global N cycle. Over the last half a century, anthropogenic perturbations of the natural N cycle have led to the increasing accumulation of inorganic Nr in the soil, water and air, intentionally through agriculture and unintentionally through fosill-fuel consumption and other activities, adversely affecting human health, biodiversity, environment and climate change.

Original Source

During January 2008, the author visited Alawa village (population nearly 1000) in Jhalawar District, Rajasthan to study scarcity of irrigation water. Armed with diesel engines, farmers were seen aggressively pumping water from two check dams located in the Ahu River

There are several procedures to control mosquitoes by chemical, mechanical, genetical or biological means. Biological control of mosquito larvae by the application of natural animal products is one of the important techniques, which is cheap, easy-to-use and environment friendly. (Correspondence)

Cotton, as a commercial crop has gone through subsistence, ecological, exploitation, crisis and disaster phases of pest management, with insecticides on focus at the later three stages. Restructuring of pest-management strategies during the last few decades under the banner of Integrated Pest Management (IPM) or Insecticide Resistance Management (IRM)continued to give considerable and selective preference respectively, to the insecticides. Such an approach could only achieve the short-term benefits of reducing the pesticide usage and improving the profit accrued by the farmers.