Submitted to: Environmental and Water Resources Institute World Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/1/2005
Publication Date: 5/15/2005
Citation: Haman, D., Sorensen, R.B., Ross, D., Evans, R., Tacker, P. 2005. CRITICAL MANAGEMENT ISSUES WHEN USING SDI IN HUMID AREAS. RWRI-Anchorage, AK. Proceedings of the 2005 World Water and Environmental and Water Resources Congress, pp 519. Interpretive Summary: None required.
Technical Abstract: The use of subsurface drip irrigation (SDI) is increasing throughout the United States. Proper SDI system management that includes water management, system maintenance and chemigation is imperative to the successful implementation of SDI. Improper or inadequate management of any system can result in poor water distribution, crop failure, and system failure. In addition, damage to pumps, filters, and drip tubing are irreversible and components must be replaced adding expense to the farming enterprise. Because working components of an SDI system are underground, it is important to establish baseline operational performance standards while the system is relatively new. Future declines in operating performance can often be diagnosed by comparing real time performance with these baseline criteria. Operational parameters to evaluate include flow rate versus operating pressure, emitter wetted area versus operating pressure, and distribution uniformity. Water management, often referred to as irrigation scheduling, is the process of determining when and how much to irrigate. Factors influencing the decision include weather, crop, soils, system design, and management criteria. Weather, crop models, and various soil and/or plant sensors can be used to determine when to irrigate, where water balance can be used to decide how much water should be applied. Water can be applied through SDI on demand in very small amounts increasing the efficiency of water application. Subsurface drip irrigation (SDI) can be used to efficiently apply chemicals such as pesticides and crop nutrients. The system has the potential to deliver low fertilizer rates over a long period of time, with increased nutrient use efficiency and lower cost per unit of harvested product. Chemical application is also used for protection of the tubing from rodents, insects, and obstructions such as intrusion of crop roots and chemical precipitates.