Deficit Irrigation Practices

Deficit Irrigation Practices

Author: Food and Agriculture Organization of the United Nations

Publisher: Food & Agriculture Org.

Published: 2002

Total Pages: 116

ISBN-13: 9789251047682

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In the context of improving water productivity, there is a growing interest in deficit irrigation, an irrigation practice whereby water supply is reduced below maximum levels and mild stress is allowed with minimal effects on yield. Under conditions of scarce water supply and drought, deficit irrigation can lead to greater economic gains than maximizing yields per unit of water for a given crop; farmers are more inclined to use water more efficiently, and more water-efficient cash crop selection helps optimize returns. However, this approach requires precise knowledge of crop response to water as drought tolerance varies considerably by species, cultivar and stage of growth. The studies present the latest research concepts and involve various practices for deficit irrigation. Both annual and perennial crops were exposed to different levels of water stress, either during a particular growth phase, throughout the whole growing season or in a combination of growth stages. The overall finding, based on the synthesis of the different contributions, is that deficit or regulated-deficit irrigation can be beneficial where appropriately applied. Substantial savings of water can be achieved with little impact on the quality and quantity of the harvested yield. However, to be successful, an intimate knowledge of crop behavior is required, as crop response to water stress varies considerably.


Agricultural Water Management

Agricultural Water Management

Author: National Research Council

Publisher: National Academies Press

Published: 2007-03-20

Total Pages: 158

ISBN-13: 0309179254

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This report contains a collection of papers from a workshopâ€"Strengthening Science-Based Decision-Making for Sustainable Management of Scarce Water Resources for Agricultural Production, held in Tunisia. Participants, including scientists, decision makers, representatives of non-profit organizations, and a farmer, came from the United States and several countries in North Africa and the Middle East. The papers examined constraints to agricultural production as it relates to water scarcity; focusing on 1) the state of the science regarding water management for agricultural purposes in the Middle East and North Africa 2) how science can be applied to better manage existing water supplies to optimize the domestic production of food and fiber. The cross-cutting themes of the workshop were the elements or principles of science-based decision making, the role of the scientific community in ensuring that science is an integral part of the decision making process, and ways to improve communications between scientists and decision makers.


Optimal Irrigation Management

Optimal Irrigation Management

Author: Charles Carter Hillyer

Publisher:

Published: 2011

Total Pages: 152

ISBN-13:

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Many regions in North America are experiencing water shortages, and these conditions are expected to worsen. The next generation of irrigation scheduling applications must therefore be capable of providing operational advice in support of deficit irrigation strategies. However, the theoretical, technical, and practical challenges associated with deficit irrigation scheduling are far more complex than conventional (full) irrigation. This dissertation presents three distinct systems for addressing the analytical challenges of deficit irrigation management. The first section of the dissertation presents a simulation framework for agro-ecological simulation. The objective was to develop a method to enable the assembly of simulation models from previously and independently developed component models. Based on a requirements analysis of existing simulation models we developed the ModCom simulation framework. ModCom provides a set of interface specifications that describe components in a simulation. ModCom also provides implementations of the core simulation services. The framework interfaces use well-defined binary standards and allows developers to implement the interfaces using a broad range of computer languages. The Second section describes the Irrigation Efficiency Model (IEM). IEM explicitly analyzes irrigation efficiency, accounts for spatial variability of soil properties and irrigation uniformity, performs simultaneous scheduling for all fields in the farm, accounts for energy use and its associated costs, and uses both ET and soil moisture measurements to enhance the accuracy of the irrigation schedules. IEM was developed specifically for implementing Deficit Irrigation and therefore includes analyses that go beyond the requirements of conventional irrigation scheduling. The third section describes Irrigation Management Online (IMO), a web application for optimum irrigation management. This system uses IEM to generate and deliver irrigation scheduling recommendations. IMO has been developed specifically to support irrigation management when either water supplies or delivery system capacities are limited. To mitigate the complexities of irrigation constraints the system has been designed so that the irrigation manager is an integral part of the irrigation optimization procedure. The final section outlines some of the key challenges that the next generation of schedulers must overcome in order to meet the needs of agricultural irrigation in an increasingly water short future. In addition, this section will discuss how irrigation advisory programs will need to operate differently in terms of what they do and how they do it.


Irrigating Efficiently

Irrigating Efficiently

Author: Joe Makuch

Publisher: DIANE Publishing

Published: 1995-07

Total Pages: 74

ISBN-13: 9780788118395

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264 citations, some with annotations, covering the field of low energy, precision &/or efficient water conservation in irrigation. Subject and author indices.