Deficit Irrigation For Wheat Cultivation Under Limited Water Supply Condition

Vertical and horizontal expansion of irrigated agriculture to feed the increasing population has contributed to excessive groundwater withdrawal and affected the availability of water in terms of both quality and quantity. To sustain agricultural growth, strategic measures should be adopted to reduce water consumption while minimizing adverse effect on yield. The effect of deficit irrigation on wheat yield was studied in three consecutive years (2002-03 to 2004-05) in field and pot. Ten irrigation treatments were imposed in a randomized complete block (RCB) design covering full deficit, no deficit at all, single deficit at different stages, and alternate deficits. Water deficit was created by withholding irrigation at different growth stages. The results indicate that deficit irrigation strategies affected all aspects of plant growth (leaf area index, chlorophyll content, root growth, nutrient uptake, plant height) adversely. Yield attributes were affected by deficit irrigation treatments although they are not statistically significant in all cases. Differences in grain and straw yield among the partial- and no-deficit treatments were small, and statistically insignificant in most cases. When compared within single-deficit treatments, the grain yield reduction was in the order to water deficit at phases: CRI> maximum tillering > booting - heading >flowering- soft dough. The crop coefficient (kc) under different ET0 methods for early, crop development, middle, and late period ranged from 0.54 to 0.96, 0.95 to 1.36, 1.2 to 1.62, and 0.68 to 1.05, respectively. On average, yield response factor (ky) for early, maximum tillering, booting-heading, and flowering-soft dough stages was 0.27, 0.21, 0.25, and 0.17, respectively. The sensitivity index (?i, of Jensen model) for early, vegetative, booting-heading, and flowering-soft dough phases was 0.35, 0.22, 0.31, and 0.14, respectively. From the evaluation of yield, irrigation amount, irrigation water productivity, relative water savings, relative yield reduction, and maximum profit under limited water resource condition, it can be concluded that when limited quantities of water is available, preference should be given to irrigate first at CRI (if one irrigation is available), then at CRI and booting-heading (if two irrigations are available), and next at CRI, maximum tillering and booting-heading (if three irrigations are available) stages of growth.

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.

Barley is one of the world's most important crops with uses ranging from food and feed production, malting and brewing to its use as a model organism in molecular research. The demand and uses of barley continue to grow and there is a need for an up-to-date comprehensive reference that looks at all aspects of the barley crop from taxonomy and morphology through to end use. Barley will fill this increasing void. Barley will stand as a must have reference for anyone researching, growing, or utilizing this important crop.

Agriculture is one of the few industries that has been creating resources conti- ously from nature. Sustainability of this industry is a crucial issue at now-a-days. Agricultural technologies are important to feed the growing world population. Agricultural engineering has been applying scienti?c principles for the optimal use of natural resources in agricultural production for the bene?t of humankind. The role of agricultural engineering is increasing in the coming days at the forthcoming challenges of producing more food with less water coupled with climate uncertainty. I am happy to know that a book entitled "Fundamentals of Irrigation and On-farm Water Management", written by Engr. Dr. M. H. Ali, is going to be p- lished by Springer. The book is designed to cover the major ?elds of agricultural and environmental engineering such as weather, plant, soil, water, and basics of on-farm water management. The book will be quite useful for the students of agricultural engineering. Students of other related branches of engineering s- ences, and engineers working in the ?eld and at research institutes will also be beni?ted. The book may serve as a text book for the students and as a practical hand-book for the practitioners and researchers in the ?eld of irrigation and on-farm water management. Utilization of the recent literature in the area and citation of relevant journals / reports have added a special value to this book. Considering the topics covered, engineers, scientists, practitioners, and educators will ?nd this book as a valuable resource.

Water Scarcity and Sustainable Agriculture in Semiarid Environment: Tools, Strategies and Challenges for Woody Crops explores the complex relationship between water scarcity and climate change, agricultural water-use efficiency, crop-water stress management and modeling water scarcity in woody crops. Understanding these cause- and effect relationships and identifying the most appropriate responses are critical for sustainable crop production. The book focuses on Mediterranean environments to explain how to determine the most appropriate strategy and implement an effective plan; however, core concepts are translational to other regions. Informative for those working in agricultural water management, irrigation and drainage, crop physiology and sustainable agriculture. Focuses on semi-arid crops including olive, vine, citrus, almonds, peach, nectarine, plum, subtropical fruits and others Explores crop physiological responses to drought at plant, cellular and/or molecular levels Presents tool options for assessing crop-water status and irrigation scheduling

First title in a major new seriesAddresses improving water productivity to relieve problems of scarcity and competition to provide for food and environmental securityDraws from scientists having a multitude of disciplines to approach this important problemIn a large number of developing countries, policy makers and researchers are increasingly aware of the conflicting demands on water, and look at agriculture to be more effective in its use of water. Focusing on both irrigated and rain-fed agriculture, this book gives a state of the art review of the limits and opportunities for improving water productivity in crop production. It demonstrates how efficiency of water use can be enhanced to maximize yields. The book represents the first in a new series of volumes resulting from the Comprehensive Assessment of Water Management in Agriculture, a research program conducted by the CGIAR's Future Harvest Centres, the Food and Agriculture Organization of the United Nations and partners worldwide. It will be of significant interest to those working in areas of soil and crop science, water management, irrigation, and development studies.

Significant vulnerability of water systems to drought is a common issue of water resources management in Mediterranean regions. This is due both to the increasing occurrence and severity of drought events and to the growing demand for municipal, tourist, and agricultural uses. The INCO-DC project entitled "A Decision Support System for Mitigation of Drought Impacts in the Mediterranean Regions" (DSS DROUGHT) addresses this issue, contributing to an improved management of water supply systems for irrigation, which represents the most consumptive sector of water resources uses in the Mediterranean region. In order to develop a comprehensive approach toward improved operation of irrigation systems under drought conditions, the project was developed around the following five main, strictly interconnected tasks: Identification of drought characteristics at a site and over a region Modelling irrigation management under conditions of water scarcity Modelling operation of water supply systems under drought conditions Integration of the developed methodologies within a Decision Support System software package Definition of requisites for Drought Watch Systems The research resulted in an advancement of knowledge through in-depth analysis of innovative methodologies, the development of tools to help decision-makers in coping with droughts through the implementation of the developed procedures in software packages, and the application of these tools to the case-studies identified by partners in their countries.

The comprehensive and compact presentation in this book is the perfect format for a resource/textbook for undergraduate students in the areas of Agricultural Engineering, Biological Systems Engineering, Bio-Science Engineering, Water Resource Engineering, and Civil & Environmental Engineering. This book will also serve as a reference manual for researchers and extension workers in such diverse fields as agricultural engineering, agronomy, ecology, hydrology, and meteorology.