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. - Identifies all significant sources of reactive nitrogen flows and their contribution to the nitrogen-cycle on a national, regional, and global level - Covers nitrogen management across sectors, including the environment, food security, energy, and health - Provides a single reference on reactive nitrogen in India to help in a number of activities, including the evaluation, analysis, synthesis, documentation, and communications on reactive nitrogen

Nitrogen is the most yield-restraining nutrient in crop production globally. Efficient nitrogen management is one of the most important factor for improving nitrogen use efficiency, field crops productivity and profitability. Efficient use of nitrogen for crop production is therefore very important for increasing grain yield, maximizing economic return and minimizing nitrous oxide (N2O) emission from the fields and nitrate (NO3) leaching to ground water. Integrated nitrogen management is a good strategy to improve plant growth, increase yield and yield components, grain quality and reduce environmental problems. Integrated nitrogen management (combined use of chemical + organic + bio-fertilizers) in field crop production is more resilient to climate change.

This book highlights the latest discoveries about the nitrogen cycle in the soil. It introduces the concept of nitrogen fixation and covers important aspects of nitrogen in soil and ecology such as its distribution and occurrence, soil microflora and fauna and their role in N-fixation. The importance of plant growth-promoting microbes for a sustainable agriculture, e.g. arbuscular mycorrhizae in N-fixation, is discussed as well as perspectives of metagenomics, microbe-plant signal transduction in N-ecology and related aspects. This book enables the reader to bridge the main gaps in knowledge and carefully presents perspectives on the ecology of biotransformations of nitrogen in soil.

Overview; Morphology and physiology of rice ratoons; Rice ratooning in practice; Evaluation and potential of rice ratooning; Cultural practices; Genetics and varietal improvement.

During the next 30 years, farmers must produce 70% more rice than the 550 millions tons produced today to feed the increasing population. Nitrogen (N) is the nutrient that most frequently limits rice production. At current levels ofN use efficiency, we will require at least double the 10 million tons of N fertilizer that are currently used each year for rice production. Global agriculture now relies heavily on N fertilizers derived from petroleUIll, which, in turn, is vulnerable to political and economic fluctuations in the oil markets. N fertilizers, therefore, are expensive inputs, costing agriculture more than US$45 billion annually. Rice suffers from a mismatch of its N demand and N supplied as fertilizer, resulting in a 50-70% loss of applied N fertilizer. Two basic approaches may be used to solve this problem One is to regulate the timing ofN application based on needs of the plants, thus partly increasing the efficiency of the plants' use of applied N. The other is to increase the ability of the rice system to fix its own N. The latter approach is a long-term strategy, but it would have enormous environmental benefits while helping resource-poor farmers. Furthermore, farmers more easily adopt a genotype or variety with useful traits than they do crop and soil management practices that may be associated with additional costs.

The steadily increasing cost of nitrogen fertilizer has resulted in more emphasis on basic and applied studies to improve nitrogen use efficiency in lowland rice. The efficiency of fertilizer nitrogen in farmers' fields is shockingly low ~ a luxury resource-scarce farmers in tropical Asia can ill afford. We believe it is critical to quantify the basic transformation processes and develop management practices for higher N use efficiency for two reasons. They are: 1. Nitrogen fertilizer together with water management is a key factor for achieving the yield potentials of modern rices. 2. Fertilizer nitrogen prices are high and most Asian rice farmers are poor. The International Rice Research Institute (IRRI), Philippines; Internation al Fertilizer Development Center (IFDC), USA; Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia; U.S. Universities (Louisiana, Cornell, California, Arkansas and others); and Dr Justus Leibig University in West Germany are actively engaged in individual or collaborative research that addresses basic transformation processes on N gains and losses and management practices to maximize N use efficiency in rice. It is appropriate to update and summarize, in a double issue of Fertilizer Research, the 10 papers presented at the special symposium organized by the American Society of Agronomy (ASA) at the 75th Annual Meeting in Washington, D.C. in 1983. S.K. De Datta, Head of Agronomy Department, IRRI, was chairman of the International Agronomy Division of ASA (A-6) in 1982 and 1983.