Agricultural systems as well as other ecosystems generate ecosystem services, i.e., societal benefits from ecological processes. These services include, for example, nutrient reduction that leads to water quality improvements in some wetlands and climatic regulation through recycling of precipitation in rain forests. While agriculture has increased ‘provisioning' ecosystem services, such as food, fiber and timber production, it has, through time, substantially impacted other ecosystem services. Here we review the trade-offs among ecosystem services that have been generated by agriculture-induced changes to water quality and quantity in downstream aquatic systems, wetlands and terrestrial systems. We highlight emerging issues that need urgent attention in research and policy making. We identify three main strategies by which agricultural water management can deal with these large trade-offs: (a) improving water management practices on agricultural lands, (b) better linkage with management of downstream aquatic ecosystems, and (c) paying more attention to how water can be managed to create multifunctional agro-ecosystems. This can only be done if ecological landscape processes are better understood, and the values of ecosystem services other than food production are also recognized.

Agriculture is central to the food security and economic growth of developing countries, providing the main source of livelihood for three out of four of the world's poor. Yet it is the poorest farmers who are most vulnerable to the impacts of climate change. This paper briefly reviews the potential impact of climate change on food crops in the context of the wider debate on future food and water security in the developing world. The authors ask whether we should wait or act now to tackle the anticipated future problems.

This book with 33 chapters divided into five parts is a compendium of selected papers from the conference that can be broadly categorized as land and water management, fisheries and aquaculture and rice-based agriculture systems. Intensification of aquaculture and rice-based agriculture frequently produces negative effects that range from environmental degradation to social conflict; managing these impacts in a sustainable manner is imperative to protect the social and ecological foundations of tropical deltaic systems. New approaches to the intensification and diversification of rice-based production systems are presented in this book, which could impact positively on the livelihoods of millions who inhabit the deltaic areas of South, South East and East Asia if implemented on a large scale. More importantly, these innovations could begin to reverse man's current exploitive behaviour and ensure the preservation of critical ecosystems. A significant section of the compendium is devoted to the intensification of marine shrimp aquaculture production. Negative impacts associated with shrimp production are well recognized, and several innovative approaches to waste management are presented. Further critical questions are raised over the introduction of exotic shrimp species and the long-term impact this could have on native species, which suggests a cautionary approach to future development. A clear consensus emerged from the conference that highlighted the importance of social mobilization and the role of communities in decision making.

Coastal deltas represent one of the most diverse biophysical regions in the tropical developing world. These regions are also home to large human populations and are significant areas of agricultural production and industrialization. Tropical deltas currently face a number of environmental pressures stemming from their intensive use and rapid development, and new threts are emerging as a result of global climate change and expected sea-level rise. | Focusing on the developing countries of Asia, Africa and South America, chapters explore the impact of development strategies and existing land and water management practices on delta environments. New management techniques are also explored, which address conflicts between rice-based agriculture, aquaculture, fisheries, and the emerging threat of climate change. Illustrating the current key management challenges involved in protecting tropical deltaic systems in the face of environmental change, this book will be an essential reference for students, researchers and policy makers in agriculture, environmental science and aquaculture. --Book Jacket.

Culture-independent techniques were used for the detection of pathogenic bacteria in drinking water at potentially critical control points along the production lines at a German dairy company and a Spanish dry cured ham company. Denaturing gradient gel electrophoresis (DGGE) was used to describe bacterial population shifts indicating biological instability in the drinking water samples. Autochthonous bacteria were identified by sequencing the excised DGGE DNA bands. More specifically, real-time PCR was applied to detect a number of pathogenic bacteria, i.e. Listeria monocytogenes, Mycobacterium avium subsp. paratuberculosis, Campylobacter jejuni, Enterococcus spp., Salmonella spp, Escherichia coli, and Pseudomonas aeruginosa. Due to the detection limits of the real-time PCR method, a specific protocol was established in order to meet the technical detection requirements and to avoid unwanted polymerase inhibitions. Autochthonous bacterial populations were found to be highly stable at most of the sampling points. Only one sampling point exhibited population shifts at the German dairy company. Enterococci and P. aeruginosa were detected in some water samples from these companies by molecular biology detection methods, but not by conventional culturing methods. Some opportunistic bacteria as Enterobacter sp., Acinetobacter, Sphingomonas sp. and non-pathogenic Bacillus, were also detected after DNA sequencing of DGGE bands.

This Medium Term Plan (MTP) describes the CPWF’s second Phase (2009-2013). The Plan is developed as a distinct set of activities, with supportive procedures and staffing, while clearly acknowledging full integration into the future CGIAR Consortium Research Program (CRP) 5 on “Land, Water and Ecosystems” led by IWMI. It describes the process adopted by the CPWF to capture lessons from its Phase 1 and the design of the research strategy based on six Basin Development Challenges (BDC) and Topic Working Groups (TWG) through which CPWF works in its Phase 2.

North Africa is one of the driest regions in the world. Consequently, all countries in the region depend mainly on agricultural imports to achieve the food security. The present study endeavor to estimate: firstly, the national and the global water saving achieved through the North African international cereal trade by using the concept of virtual water trade. Secondly, the relation between the imports of cereal trade, as endogenous variable, and the available water resources availability with other important factors as exogenous variables. The results showed that, at the national level, all North African countries achieved water saves to the extent that exceed the endowment total fresh water resources in Libya, Algeria, and Tunisia. Importing of maize and wheat is the most important player of the saving national water imports of among the cereal crops. All countries in the North Africa region achieved water saving except Egypt. The model results has shown statistically significant coefficients of factors affecting the total imports of cereal crops such as, per-capita fresh water resources, the area of irrigated water, the area of Arable land . the negative sing of per-capita fresh water resources indicates that the importing cereals using intensive water is not optional decision but due to the shortage of the available of water resources . Negative signs of irrigated area and of arable land are consistent indicating that the increasing of the irrigated area and the arable land will intuitively reduce the importing of cereals.

The authors of the recently completed Comprehensive Assessment of Water Management in Agriculture (CA) concluded that there are sufficient water resources to produce food for a growing population but that trends in consumption, production and environmental patterns, if continued, will lead to water crises in many parts of the world. Only if we act to improve water use will we meet the acute fresh water challenge. Recent spikes in food prices, partially caused by the increasing demand for agricultural products in non-food uses, underline the urgent need to invest in agricultural production, of which water management is a crucial part. The world experienced similar pressure on per capita food supplies and food prices in the 1960s and 1970s, but the challenges now are different than those we experienced 50 years ago. The world's population is substantially larger, there are many more people living in poverty, and the costs of many agricultural inputs are much higher. The current situation and the long-term outlook require a fresh look at approaches that combine different elements such as the importance of access to water for the poor, providing multiple ecosystem services, rainwater management, adapting irrigation to new needs, enhancing water productivity, and promoting the use of low-quality water in agriculture. This special issue highlights the analysis behind a number of policy options identified by the CA, a five-year multi-disciplinary research program involving 700 scientists. This introductory article sets the background and context of this special issue, introduces the key recommendations from the CA and summarizes the papers in this issue.