A Technical Advisors Manual Managing Agricultural Irrigation Drainage Water

This book documents the history of irrigated agriculture and drainage in the San Joaquin Valley, and describes the hydrology and biogeochemical processes of salts and selenium, remediation technologies for salts and trace elements and policy and management options. The contents are comprised of fourteen chapter-length independent treatises, each depicting with fresh perspective a distinctive salinity drainage topic. The opening chapters detail the evolution of irrigated agriculture, and depict the geochemical and hydrological processes that define the San Joaquin Valley, including the physics, chemistry, and biology attributes that impact water management policies and strategies. Next, the contributors address the biogeochemistry of selenium, the role of plants in absorbing it from soils, and the processes involved in retaining and concentrating dissolved salts in drainage water. Further chapters describe on-farm and plot-level irrigation provisions to reduce agricultural drainage outputs and examine their effects on plant performance. This volume offers realistic policy analysis of water management options for irrigated agriculture in the Valley and assesses their respective outcomes, if implemented. Also included is an international perspective on the sustainability of irrigated agriculture there.

The world is faced with a growing number of complex and interconnected challenges. Water is among the top 5 global risks in terms of impacts, which would be far reaching beyond socio-economic challenges, impacting livelihoods and wellbeing of the people. As freshwater resources and population densities are unevenly distributed across the world, some regions and countries are already water scarce. Water scarcity is expected to intensify in regions like the Middle East and North Africa (MENA), which has 6% of the global population, but only 1% of the world’s freshwater resources. Climate change adds to this complexity as it is leading to rainfall uncertainty and extended droughts periods, mostly in arid areas. Increasing water scarcity is now recognized as a major cause of conflict, social unrest and migration and at the same time water is increasingly considered as an instrument for international cooperation to achieve sustainable development. Tapping and assessing sustainably every available option in water-scarce areas is needed as pressure continues to build on limited water resources. The stark fact is that conventional water provisioning approaches relying on snowfall, rainfall and river runoff are not enough to meet growing freshwater demand in water-scarce areas. Water-scarce countries need a radical re-think of water resource planning and management that includes the creative exploitation of a growing set of viable but unconventional water resources for food production, livelihoods, ecosystems, climate change adaption, and sustainable development. Unconventional water resources are generated as a by-product of specialized processes; need suitable pre-use treatment; require pertinent on-farm management when used for irrigation; or result from a special technology to collect/access water.

This paper provides the basis for the preparation of manuals necessary for managers and staffs to perform needed activities at the proper time. The guide provides a comprehensive list of issues that should be addressed in operation and maintenance manuals for irrigation and drainage systems, and a listing of published materials and working papers which will assist in the formulation of plans for operation and maintenance. The paper serves as a valuable tool to help improve the performance of irrigation and drainage systems and to assist managers in developing and improving effective organizations to serve water consumers better.

In many countries irrigated agriculture consumes a large proportion of the available water resources, often over 70% of the total. There is considerable pressure to release water for other uses and, as a sector, irrigated agriculture will have to increase the efficiency and productivity of its water use. This is particularly true for manually operated irrigation systems managed by government agencies, which provide water for a large number of users on small landholdings and represent 60% of the total irrigated area worldwide. Drawing on the author's 30 years of experience in some 28 countries, this book offers knowledge of the management of irrigation and drainage systems, including traditional technical areas of systems operation and maintenance, and expanding managerial, institutional and organizational aspects. Chapters provide guidelines to improve management, operation and maintenance processes, which move management thinking out of traditional public-sector mindsets to a more customer-focused, performance-oriented service delivery. As a practical guide to improve efficiency and productivity in irrigated agriculture, this book will be essential reading for irrigation managers and technicians as well as students and policy makers in water management, agriculture and sustainable development.

The irrigation water is considered as the essential input for crop production. Over exploitation of natural water resources has caused a menace for the future human generations. The depletion of underground water table in high productivity areas and under utilization of the water resources in rain fed areas of the country, poor irrigation efficiency and high seepage losses from conveyance system, poor land development and mismanagement of the irrigation water resources has acquired alarming proportions. As the share of water for agriculture in future is going to reduce, there will be tremendous pressure to produce more per drop of water in order to meet the food and other requirements of burgeoning population of the country. The existing irrigation water resources are not utilized judiciously and their mismanagement has lead to problems like low production efficiency, salinization, water logging and degradation of land. To manage these problems and increase the production efficiency of irrigation, it is pertinent to adopt judicious methods of irrigation water use, by efficient on-farm irrigation management based on scientific approach. Therefore, a comprehensive knowledge of available soil moisture and its constants, scheduling and quality of irrigation water and proper drainage techniques is crucial. This manual on irrigation engineering is an attempt to fulfil this urgent need as it covers all major aspects of irrigation water management. Although, manual is meant primarily for the students of agricultural universities, yet it will provide valuable basic information and guide to the scientific community and field functionaries.

Ethanol as an alternative fuel is receiving a lot of attention because it addresses concerns related to dwindling oil supplies, energy independence, and climate change. The majority of the ethanol in the US is produced from corn starch. With the US Department of Energy’s target that 30% of the fuel in the US is produced from renewable resources by 2030, the anticipated demand for corn starch will quickly exceed the current production of corn. This, plus the concern that less grain will become available for food and feed purposes, necessitates the use of other feedstocks for the production of ethanol. For the very same reasons, there is increasing research activity and growing interest in many other biomass crops. Genetic Improvement of Bio-Energy Crops focuses on the production of ethanol from lignocellulosic biomass, which includes corn stover, biomass from dedicated annual and perennial energy crops, and trees as well as a number of important biomass crops. The biomass is typically pretreated through thermochemical processing to make it more amenable to hydrolysis with cellulolytic enzymes. The enzymatic hydrolysis yields monomeric sugars that can be fermented to ethanol by micro-organisms. While much emphasis has been placed on the optimization of thermo-chemical pretreatment processes, production of more efficient hydrolytic enzymes, and the development of robust microbial strains, relatively little effort has been dedicated to the improvement of the biomass itself.

This book has been prepared to help organizations responsible for operation and maintenance of irrigation and drainage systems to develop strategies and prepare plans for proper and effective operation and maintenance. It provides the basis for the preparation of manuals necessary for managers and staff to perform needed activities at the proper time. The guide provides a comprehensive list of issues that should be addressed in operation and maintenance manuals for irrigation and drainage systems, and a listing of published materials and working papers which will assist in the formulation of plans for operation and maintenance. The guide should serve as a valuable tool to assist managers in developing and improving effective organizations to serve water consumers better.