Allen R. Dedrick

The Management Improvement Program (MIP): A Process For Improving 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.

Irrigation management for groundwater quality protection

Deep percolation flow below agricultural and can transport nitrate and pesticide residues to underlying groundwater. Irrigated agriculture in dry climates can also contaminate groundwater with salt from irrigation water and with trace elements such as selenium leached from the vadose zone. Groundwater contamination by agricultural chemicals can be minimized by using best management practices (BMPs) for crop production (including low-input sustainable agriculture or other source control) and for irrigation. Irrigation systems should be designed and managed for zero or minimum deep percolation during the growing seasons to keep fertilizer and pesticides in the root zone as long as possible. At other times, irrigation efficiencies can be lower to produce enough deep percolation water for leaching salts out of the root zone. Because of spatial variability and preferential flow, however, some deep percolation and movement of chemicals may still occur, even if the irrigation efficiency is 100%. BMPs should be developed to minimize such deep percolation flow.

Estimating Distribution Uniformity in Level Basins

ABSTRACT TWO different methods are presented for estimating the distribution uniformity in level basins. The method to be used depends upon the infiltration characteristics of the soil. For soils whose infiltration can reasonably be described by a power function, the distribution uniformity is a function of the ratio of ad-vance to opportunity time and the exponents of the in-filtration and water advance (power) functions. A graphical solution of distribution uniformity was presented. We found that the advance exponent had a relatively minor effect on the results compared to the in-filtration exponent. For soils in which the infiltration rate becomes constant rather than following the power function until infiltration is complete, the distribution uniformity is a function of the advance exponent, the ad-vance time, the final infiltration rate and the average depth infiltrated. For this infiltration function, the distribution uniformity can be calculated directly, mak-ing this method more straightforward and easier to use. The application efficiency can be determined provided that the entire field receives the desired amount of water, otherwise, only upper and lower limits can be determin-ed.

On-farm system performance in the Maricopa-Stanfield Irrigation and Drainage District area.

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.

Diagnostic Analysis of the Maricopa-Stanfield Irrigation and Drainage District Area

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.

Water delivery performance in the Maricopa-Stanfield Irrigation and Drainage District

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 areas irrigated agricultural system. Partof the Diagnostic Analysis study focused on the performance ofthe irrigation districts 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 systems management. Results from a post-MIP intervention study indicate that the districts 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.

Delivery system performance case study: Wellton-Mohawk irrigation and drainage district, USA

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.

Automation of an Open-Ditch Irrigation Conveyance System Utilizing Tile Outlets

ADSTRACT NEARLY 80 percent of the irrigated lands in the United States use surface irrigation techniques. Most of the on-farm, irrigation-water distribution systems are of the open-ditch type. The latest trend in western Arizona and parts of California is to dead-level fields, then irrigate from single or multiple outlets with large streams of water. These level basins are well adapted to automation. An automated irrigation sys-tem reduces farm labor requirements and, as an irri-gation management tool, can reduce water applica-tion, improve crop production, and minimize scalding and thus stand loss. A 28.4-ha (70-acre) field irrigated with tile outlets was pneumatically automated using two types of pillows on the outlet side, in combination with automated jack-gates, from a centrally located concrete-lined canal. The present system is being used by the farmer, observed and amended by the researchers, and demon-strated to many US and foreign visitors.

Multipurpose Head Detection and Monitoring Unit

ABSTRACT A water level (head) detection unit was developed which is versatile in its application. The system used an inexpensive pressure transducer and double-bubbler scheme for sensing water head. The double-bubbler scheme provides a method for continual calibration of the pressure transducer (offset and gain compensated). Head detection accuracy was within ± 1 mm over a wide temperature range. This scheme is monitored and controlled by a hand-held programmable electronic calculator. The calculator and peripheral devices can be used to compute a variety of parameters of interest. This unit has been used along with a measuring flume or weir to record and accumulate flow. It has also been used to monitor infiltration for a flowing furrow infiltrometer. The unit can also be adapted to record water levels from several locations. Since the unit is programmed by simple calculator functions, it is rather simple to convert to new applications.

Trailer Mounted Flowing Furrow Infiltrometer

INFILTRATION processes must be understood to optimally design, evaluate or manage furrow irrigation systems. The utility of evaluating furrow infiltration using flowing water rather than static water has been demonstrated previously. A self contained, trailer-mounted, flowing furrow infiltrometer was developed by the Soil Conservation Service cooperatively with the Agricultural Research Service in Arizona to assist in characterizing the furrow infiltration phenomena under field conditions. A description of the equipment, procedure for its use, and sample calculations of infiltration are presented.