Irrigated agriculture faces a crisis because of the urgent needs for increasing productivity, current and increasing severe water shortages, and the increasingly serious impacts of irrigation on the environment (FAO, 1996). Changing individual professionals and the bureaucracies involved in irrigated agriculture to meet these urgent challenges also is daunting. Observations at a general level suggest the changes needed by international consultants, international donor, and research and development organizations, and national and local organizations including farmer organizations also are not achievable. Accomplishing changes in conceptual understanding and specific operational procedures for individuals and organizations is the current urgent need. This paper identifies some urgent changes needed and defines the conceptual and operational strategies that can address the needs and accomplish the changes. The results provide for improved performance in productivity, for making more effective use of water supplies while making available additional water supplies for irrigation and other uses, and for approaching environmental sustainability in irrigated agriculture. Urgent needs relate to productivity, water scarcity, and managing the environment. Conceptual understanding and operational procedures applicable to improving system management and performance, and management changes in individuals and organizations are the changes necessary to meet the urgent needs in irrigated agriculture. The basis for these observations is more than 35 years of involvement in irrigated agricultural research and development with many organizations and individuals in many countries.

Agriculture in Pakistan suffers from low levels of productivity and inadequate management. The Irrigation andAgricultural Departments are largely dysfunctional because of inadequate top level commitment, and dysfunctional units within thesedepartments. Water supplies are poorly managed, and reforms of the provincial Irrigation Departments are failing because ofinadequate top level support, technical support to the farmers and vested interests that are assuring failure. Current production ofmajor crops equals only 15% to 30% of record yields. Regulation of groundwater development and management of conjunctive useof water supplies is nonexistent but urgently needed. Saline-sodic water, pumped from groundwater by more than 70% of theexisting tubewells, creates serious salinity problems that are not being addressed by available technologies. Along withstrengthening the ongoing structural reforms in the provincial Irrigation Departments, we recommend similar reforms in theAgricultural Departments. The reforms should be undertaken in tandem by creating Land and Water Management Authorities thatprovide Technical Support Teams at the Farmer Organization level. The reforms follow but improve the reforms of the provincialIrrigation Departments that are currently failing. The proposed land and water management units support farmer organizations atthe secondary canal level to create effective managers of irrigated agriculture. Different tiers of the recommended Land and WaterManagement Organization, with Boards consisting of a farmer majority, sets policies and programs for irrigation and agriculture atthe secondary canal, canal command, provincial and federal levels to effectively support irrigated agriculture.

The concept is that water management improvements in an irrigated valley cannotsave water for other uses. This concept is based upon erroneous assumptions, and thereforeuntrue. Water management improvements reduce the demand at the field. Reduced demandcan be transferred up the system and results in less water being released at the reservoir.Reduced demand is water saved that can be used to replace return flows with the remainingwater available for reallocation to other uses. The water saved has an effective value muchgreater than the actual value of the return flows because of its low salinity as well as otherpotential benefits. Budget applications in Egypt and Pakistan suggest water available forreallocation could easily range between 25 and 50% of the current annual supply for irrigation inthese water short valleys. New management strategies should be developed, tested andimplemented for an irrigated valley that enhance water supply, reduce the impacts of salinity,and limit the environmental impacts of irrigation. Water management improvements also offerthe opportunity to improve substantially the productivity of irrigated agriculture to meet growingurgent food demands.

Farm water management, particularly the application of water to fields, urgently needs improvement around the world. Traditional design approaches often do not adequately consider farmers' management practices. Advance distance design criteria for managing level basins use farmer management criteria. Advance distance designs provide appropriate application amounts, even without water measurement when flow rates fluctuate widely, when Manning n values and infiltration rates differ significantly from design values, and even compensate for changes in depth when soil-water depletion differs from the target level. This improved design approach provides a basis for improving farmer water management practices where level basins are used. Design alternatives include completion-of-advance, partial completion of advance, and individual event and seasonal management strategies. Precision land leveling is essential for high performance with level basins.

Diagnostic Analysis (DA) is a methodologyfor assessing and understanding the performance of anagricultural system. This analysis is thefirst step in a large system change process, known asthe Management Improvement Program (MIP), whoseobjective is to improve the performance of the agricultural system.A group of Federal andstate of Arizona agencies agreed to apply the MIPmethodology in a western U.S. setting. The purpose of theapplication was to test the applicability of the MIPapproach and to refine themethodology. This paper describes how the DAmethodology was applied in the Maricopa-StanfieldIrrigation and Drainage District (MSIDD) area incentral Arizona, USA, and summarizes the lessonsderived from that experience. Specific findings ofthe DA study and the response of MSIDD areaagriculture to those findings are discussed inseparate articles.

The Management Improvement Program,a process based on Organizational Developmentprinciples and methods, was applied to an irrigatedagricultural system in Arizona, USA. The MIP seeks toimprove management and performance of the agriculturalsystem through structured diagnosis, planning, andimplementation activities with the participation ofsystem stakeholders. An equally important objectiveof the demonstration project was to identify strengthsand shortcomings of the MIP methodology and togenerate recommendations for managing its futureapplications. The data used to analyze thedemonstration project's management were obtainedthrough formal interviews and informal conversationswith individual participants, program review andfeedback sessions, and records of meetings andindividual communications.

A detailed Diagnostic Analysis (DA)was performed on an irrigation district in CentralArizona as part of a Management Improvement Program(MIP). The DA was conducted by an interdisciplinaryteam who focused their findings on performance of theirrigated agricultural system, on- and off-farm,rather than on disciplines. This paper reports on thefindings related to on-farm management. Specificfindings are presented relative to farm water use,soil sustainability, the interactions between the farmirrigation system and the water delivery system, andthe adoption and transfer of new technology. Theresults point to the need for appropriate applicationof technology, ongoing farmer education, andcoordination of farm and district operations andgovernment agency programs. The interdisciplinarynature of the DA team was essential for properlyassessing performance. Although this study was donein the state of Arizona in the USA, the methodologyused and some of the general conclusions areapplicable to other locations, both within and outsidethe United States.

A Diagnostic Analysis was conducted in the service area of theMaricopa-Stanfield Irrigation and Drainage District in Arizona,USA. The study was an initial step in a managed change process,named Management Improvement Program (MIP), aimed at improvingthe performance of the area's irrigated agricultural system. Partof the Diagnostic Analysis study focused on the performance ofthe irrigation district's water delivery service. The studyidentified areas of high and low water delivery performance,factors contributing to the observed levels of performance, andimplications to on-farm water management. These findings promptedchanges in the delivery system's management. Results from a post-MIP intervention study indicate that the district's waterdelivery performance has improved as a result of those changes,and thus, that the Diagnostic Analysis and MIP methodologies areeffective tools for promoting positive change in a water deliveryorganization.

Population increases currently exceed food production increases, Therefore, irrigated agriculture must increase production as a major contributor to meeting those food needs. Three decades of experience have provided insights on the causes of irrigated agriculture's inadequate performance. Water delivery service limits improved water management and productivity. Inputs and services for farmers limit productivity. Agencies do riot effectively support farmers' needs. A management process, commonly used with public and private organizations, has proven effective at meeting irrigated agriculture's needs for change. An interdisciplinary field study provides an understanding of needs. A management specialist supported interorganizational process with farmers creates a common understanding of these needs based upon the field study and the knowledge and experience of the participants. Plans to improve and sustain performance are created.Collaborative, coordinated efforts by local, state, and federal agencies, and farmers improved the performance of irrigated agriculture.

Enhanced long-term management ofnatural resources, farmer profitability, and overallsocial well-being are essential to sustainableirrigated agriculture. Because these objectives oftenseem to conflict, all agriculturalstakeholders – farmers, irrigation districts, supportand regulatory government agencies, and otherinterested parties – need to interact proactively toidentify and address common needs. To this end, theManagement Improvement Program (MIP) was tested in theMaricopa-Stanfield Irrigation and Drainage District(MSIDD) area in central Arizona, USA, as a managedchange process to improve the performance of anirrigated agricultural system. The three-phased MIPprocess consists of (1) analysis of the currentperformance of the agricultural system, on- andoff-farm, to gain a common, shared understanding; (2) developmentby the stakeholders of plans foralternatives to address identified opportunities forimprovement; and (3) collaborative implementation ofthe plans. This paper describes the MIP process andits methodological origins, provides an account of theinitial application of the MIP process to an irrigatedagricultural system in the United States, andhighlights some important outcomes of the MIPapplication.

Procedures for analyzing the effects of uncertainties on the on‐farm time of application and applied depth of irrigation have been presented using two parameter‐gamma densities for the different variables. The critical coefficient of variation (CV) in delivered farm flow rate beyond which variations in targeted depths cause more deviations in time of application is found to be 0.25. For a typical set of values for on‐farm variables, reducing the CV of farm flow below 0.12 does not improve the variance in applied depth for the case of fixed CV values of 0.10 for farm area and time of application. A distribution function for time of application has been derived which will enable the computation of reliable levels of application time. Solving the yield problems considering the application system hydraulics in a deterministic mode does not lead to large errors when the variances in the on‐farm variables do not exceed 0.20. Generally, for shorter basins which are common in many countries, higher efficiencies can be achieved. Efficiencies less than 85% begin to occur when the length of the basin exceeds 275 ft (84 m) for typical values of field parameters in soils belonging to the Soil Conservation Service infiltration family of 3.0.

An irrigation district in southwestern Arizona was studied to assess the performance of its water delivery system. Data were obtained through monitoring of lateral canals, examining water order reports and bills, and conducting a diagnostic analysis of the water delivery and on-farm irrigation systems through interviews. A number of differences between official andde facto district operating policies were found. These policies had changed over the years and provided far more flexibility and better service than provided by the original official policy. The canal system, which was designed to be operated under upstream control, was found to be operated under a complex mixture of manual upstream and downstream control that resembled dynamic regulation. Farmers made official (recorded) water orders only about half the time. Deliveries usually occurred within one day of the ordered date, as per district policy, with more late deliveries at the tail end of the system during peak water use periods. On average, the district delivered the rate and duration ordered, but average flow rates for individual deliveries were not accurately estimated due to fluctuating flows. The two biggest shortfalls observed were the lack of water measurement records at intermediate points in the system and lack of thorough water accounting. These shortfalls appeared to have had only a minor effect on overall district objectives.

ABSTRACT Level basins are designed based upon completion-of-advance irrigation. Designs are used for fields where water control is not practical or practiced. The design determines either the run length or the infiltrated depth when the other is specified. The resulting design provides for applying a relatively constant infiltrated depth when the unit inflow rate varies by a factor of four from a target unit inflow rate.

ABSTRACT Zero inertia modeling was used to evaluate completion-of-advance irrigation in level basins with no run-off for use where inadequate control of water delivery exists. Distribution uniformity was good to extremely high for a wide range of conditions. The average depth of infiltration varied only moderately with large differences in the unit inflow rate. The effects on performance caused by errors in the soil surface parameters were moderate and can be compensated for. Completion-of-advance irrigation can be used by farmers to manage the application of a specific amount of water in the absence of water control.