|Ayars, James - Jim|
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 12/15/2005
Publication Date: 7/13/2006
Citation: Ayars, J.E., Basinal, L., Cervinka, V. 2006. On-farm disposal of saline drainage water. ASABE Annual International Meeting. Vol and pg nos pending. Interpretive Summary: Disposal of saline drainage water is one of the most difficult environmental problems facing the sustainability of irrigated agriculture in arid and semi-arid environments around the world. Decreasing our dependence on irrigated agriculture will not be possible with the increase in demand for food and fiber due to increasing world population. Disposal options that have been considered include in-situ use by crops and reuse as supplemental irrigation. These options still require a disposal of a finite amount of drainage water into the environment and generally to a surface water supply. Studies by researchers in California have resulted in the development of an on farm drainage management system designed for the disposal of saline drainage water in an environmentally sound manner. The system has been called Integrated On-Farm Drainage Management (IFDM) and has been adopted by several major growers on the westside of the San Joaquin Valley. An IFDM system requires improved irrigation system design and management, a subsurface drainage system with control structures, and a solar evaporation system (solar evaporator). In addition to the changes in the physical structure, there has to be changes in the agronomic system that include salt and water management on both salt sensitive and salt tolerant crops. This paper discusses the essential elements in the design of an IFDM system and reports on example applications on two farms in the Central Valley of California.
Technical Abstract: Disposal of saline drainage water from irrigated agriculture is a significant world-wide problem. Researchers in the San Joaquin Valley (SJV) of California developed an integrated on farm drainage water management system (IFDM) that can be used to solve this problem in an environmentally sound method. The IFDM system uses existing irrigation and drainage systems and adds a solar evaporator as the final component in a process that includes the cyclic reuse of drainage water to concentrate salts and reduce drainage volume. Irrigation water is applied to salt sensitive crops and the drainage water is collected and applied to more salt tolerant crops. This process is repeated until the salt content in the drainage prohibits use on crops. Finally the water is put into an evaporator. The critical parts of the operation of this system are improving irrigation water management to the highest economic level and providing control on the drainage system. Improving irrigation will reduce the total water for disposal and control the drainage system will allow water table regulation which will improve in-situ crop water use. IFDM systems are currently in operation in the SJV. This manuscript discusses the implementation of these concepts and describes the application on 2 farms.