DEVELOPMENT OF SUSTAINABLE PRODUCTION SYSTEMS AND WATER MANAGEMENT TECHNOLOGY FOR THE MID SOUTH
Location: Crop Production Systems Research Unit
Title: Mississippi web-based irrigation scheduling tool
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: March 8, 2011
Publication Date: May 1, 2011
Citation: Sassenrath, G.F., Schmidt, A., Pringle, H.C., Shrestha, B., Fisher, D.K. 2011. Mississippi web-based irrigation scheduling tool. National Cotton Council Beltwide Cotton Conference, Atlanta, GA, Jan 4-9, 2011. CD-ROM, pp. 7-9.
Interpretive Summary: Wise water management is important. Increasing use of water in the Mid-South is depleting aquifer levels. Now, more than ever, it is important to apply irrigation water with conservation of this precious resource in mind. Scheduling irrigation based on crop needs can optimize crop yields and may save farmers money by reduced pumping expenses. The best timing and amount of water to irrigate can be determined by knowing the soil moisture that is available for plant growth. Available soil moisture can be determined by “feel,” sensors placed in soil, or estimation based on weather conditions. An Irrigation Scheduler that is under development uses a “checkbook” method to estimate soil water content. Initial water in the soil, plus additions of water from rainfall or irrigation, minus water used by the crop or evaporated from the soil equals the estimated soil moisture content. The Irrigation Scheduler is being designed to help farmers improve their crop production while conserving water. Farmers designate their fields, wells and irrigation system specifications on topographic maps. The program imports soil and weather data from national databases. With rainfall and irrigation application amounts entered by the farmer, the scheduler is able to calculate crop water use and indicate when irrigation is required based on soil moisture. The system runs off a central server, so no software installation is required. With incorporation of information from national databases, user input of information is minimized.
Increasing use of water in the Mid-South has begun to deplete water levels in aquifers, with few guidelines in place for farmers as to when and how much to irrigate. Irrigation can increase crop yields when water is applied correctly. Irrigation scheduling is a method of managing water to better match the timing and application of irrigation with crop water use. The Mississippi Irrigation Scheduling Tool (MIST) is being developed for Mississippi to assist producers in developing good irrigation scheduling practices. The MIST system allows producers and crop consultants to track crop water use and develop an irrigation schedule for crop production. The irrigation scheduler is based on estimating crop water use from weather conditions and estimating total available soil moisture. A water balance is determined by taking the initial water in the soil, adding water from rainfall or irrigation, and subtracting water used by the crop or evaporated from the soil (ET). This “checkbook” method keeps track of the available water content of the soil and indicates the need for irrigation when the available soil water falls below that which is readily available for the plant. The checkbook method relies on knowledge of crop water use characteristics, soils, and weather during the growing season to make estimates of daily crop water use and show the need for irrigation. The web-based system is designed to automatically import information from national soil and weather databases into a central server, decreasing input requirements for the end user. The irrigation scheduling system will give farmers important tools for improving their crop production system while conserving precious water resources.