All biomass is derived from photosynthesis. This provides us with food fuel, as well as fibre. This process involves conversion of solar energy, via photochemical reactions, into chemical energy. In plants and cyanobacteria, carbon dioxide and water are converted into carbohydrates and oxygen. It is the best studied research area of plant biology. We expect that this area will assume much greater importance in the future in view of the depleting resources ofthe Earth's fuel supply. Furthermore, we believe that the next large increase in plant productivity will come from applications of the newer findings about photosynthetic process, especially through manipulation by genetic engineering. The current book covers an integrated range of subjects within the general field of photosynthesis. It is authored by international scientists from several countries (Australia, Canada, France, India, Israel, Japan, Netherlands, Russia, Spain, UK and USA). It begins with a discussion of the genetic potential and the expression of the chloroplast genome that is responsible for several key proteins involved in the electron transport processes leading to O evolution, proton release and the production of 2 NADPH and A TP, needed for CO fixation. The section on photosystems discusses 2 how photosystem I functions to produce NADPH and how photosystem II oxidizes water and releases protons through an "oxygen clock" and how intermediates between the two photosystems are produced involving a "two electron gate".

Sulphur (S) plays a pivotal role in various plant growth and development processes being a constituent of sulphur-containing amino acids, cysteine and methionine, and other metabolites viz., glutathione and phytochelatins, co-factor of enzymes which contribute to stress repair and amelioration of heavy metal toxicity. Besides, a number of S-containing components are biologically active and, thus, a source for use as medicinal value. The basic global issue before the agricultural scientist and world community is to evolve cultivars and develop methodologies for efficient use of inputs to enhance agricultural productivity. This is particularly true of the developing countries which are going to see maximum rise in population with changing food demands and declining availability of land. Amongst the inputs, nutrients play a crucial role. The major requirement is for N, P and K followed by several micro-nutrients. In this context reports of world-wide S deficiency in the agricultural systems are relevant. The reasons are many. Broadly speaking reduction inS emission, use of S-free N, P and K fertilizers and higher biomass production contributed the maximum. Despite the need for sulphur as an essential plant nutrient and the substantial returns expected from its use, very little attention has been given to fill the gap between supply and demand of S.

Sulphur (S) plays a pivotal role in various plant growth and development processes being a constituent of sulphur-containing amino acids, cysteine and methionine, and other metabolites viz., glutathione and phytochelatins, co-factor of enzymes which contribute to stress repair and amelioration of heavy metal toxicity. Besides, a number of S-containing components are biologically active and, thus, a source for use as medicinal value. The basic global issue before the agricultural scientist and world community is to evolve cultivars and develop methodologies for efficient use of inputs to enhance agricultural productivity. This is particularly true of the developing countries which are going to see maximum rise in population with changing food demands and declining availability of land. Amongst the inputs, nutrients play a crucial role. The major requirement is for N, P and K followed by several micro-nutrients. In this context reports of world-wide S deficiency in the agricultural systems are relevant. The reasons are many. Broadly speaking reduction inS emission, use of S-free N, P and K fertilizers and higher biomass production contributed the maximum. Despite the need for sulphur as an essential plant nutrient and the substantial returns expected from its use, very little attention has been given to fill the gap between supply and demand of S.

The Indian Nitrogen Assessment: Sources of Reactive Nitrogen, Environmental and Climate Effects, and Management Options and Policies provides a reference for anyone interested in Reactive N, from researchers and students, to environmental managers. Although the main processes that affect the N cycle are well known, this book is focused on the causes and effects of disruption in the N cycle, specifically in India. The book helps readers gain a precise understanding of the scale of nitrogen use, misuse, and release through various agricultural, industrial, vehicular, and other activities, also including discussions on its contribution to the pollution of water and air. Drawing upon the collective work of the Indian Nitrogen Group, this reference book helps solve the challenges associated with providing reliable estimates of nitrogen transfers within different ecosystems, also presenting the next steps that should be taken in the development of balanced, cost-effective, and feasible strategies to reduce the amount of reactive nitrogen.

This volume illuminates the disciplinary character of photosynthesis, which spans (bio)physics to agronomy. The book will help provide students with the necessary conceptual outlook for integrating information from the bioenergetic and enzymatic angles, obtained at the molecular level, with the physiology of chloroplasts, leaves and eventually crops. It therefore serves the larger interests of both students and researchers in the areas of agriculture, biotechnology, biochemistry, biophysics, plant physiology, and molecular biology, who are engaged in studying not only the basic aspects of photosynthesis, a major process determining biomass production, but also its relationship to plant productivity.

Nitrogen fertilizers are the inescapable necessity to enhance agricultural production and to sustain food security. However, their inefficient use accrues from inherent limitations of the crop plants as well as the manner in which N fertilizers are formulated, applied and managed. Excessive accumulation of N in the environment leads to soil acidification, pollution of groundwater and eutrophication of surface water, posing a public health problem as well as ecosystem imbalance. Moreover, the ozone layer depletion and greenhouse effects of NOx gases have global implications. Agricultural Nitrogen Use: Environmental Implications provides a comprehensive, interdisciplinary description of problems related to the efficient use of nitrogen in agriculture, in the overall context of the nitrogen cycle, its environmental and human health implications, as well as various approaches to improve N use efficiency. The book is presented in six sections: N Use, Flows and Cycling in Agricultural Systems; N Use Efficiency in Crop Ecosystems; Management Options and Strategies for Enhancing N Use Efficiency; Plant Physiological and Molecular Aspects of Enhancing N Use Efficiency; Role of Legumes and Biofertilizers in Agricultural N Economy; and Environmental and Human Health Implications.