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Title: PRECISION CENTER PIVOT IRRIGATION FOR EFFICIENT USE OF WATER AND NITROGEN

Author
item EVANS, ROBERT - WASHINGTON STATE UNIV
item HAN, SHUFENG - WASHINGTON STATE UNIV
item Schneider, Sally
item KROEGER, M - WASHINGTON STATE UNIV

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/23/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: The amount of water and fertilizer that is needed for good crop growth is not the same in all sections of large fields. Most irrigation systems, which can also be used to apply nitrogen fertilizer, put the same amount of water and fertilizer over the entire field. Some parts of the field get to much, which wastes water and nitrogen, has the potential to pollute the groundwater with the excess fertilizer, and can cause poor crop growth. Other parts receive too little water and fertilizer resulting in small, poorly growing plants. Center pivot and linear move irrigation systems wal across fields. Control and communication systems were developed to allow these systems to apply different amounts of water and fertilizer as they move across different sections of the field. The irrigation system sends a message with its current location in the field to a computer. The computer looks up that section of the field in its database to find out how much water and fertilizer is needed. The computer then sends a message back to the irrigation system telling it which sprinklers should turn on. When the irrigation system reaches the next section of the field, it sends another message to the computer, with its new location, and receives from the computer a new set of instructions. This system gives farmers the ability to customize the application of water and fertilizer in their fields. As a result, less water and fertilizer are wasted, healthier plants can be grown across a whole field, and there is less likelihood of excess fertilizer entering the groundwater.

Technical Abstract: Precision applications of irrigation, fertilizer and pesticides, considering field variability for self-propelled (SP) irrigation systems is discussed. Site-specific soils and climatic data are linked through a detailed GIS to SP irrigation, plant growth and irrigation scheduling models to produce field prescription maps. Prototype precision control systems have been developed, installed and field tested. The hardware, software and communications systems for precision applications work well, however, the major limitation is the inability to rationally develop coherent prescriptions.