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Automation of Subsurface Drip Irrigation for Crop Research
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.orgCitation: Pp. 809-816 in Proceedings of the World Congress of Computers in Agriculture and Natural Resources (13-15, March 2002, Iguacu Falls, Brazil) 701P0301.(doi:10.13031/2013.8415)
Authors: Clinton C. Shock, Erik B. G. Feibert, Lamont D. Saunders, and Eric P. Eldredge
Keywords: water management, Allium cepa, onion, Solanum tuberosum, potato, Watermark, granular matrix sensor, soil water potential, SDI
Automatic feedback control of precision irrigation scheduling allows the determination of optimum soil water potential for crops, close determination of N fertilizer requirements, and other measures of crop development and yield responses. Soil water potential (SWP) was measured with granular matrix sensors (GMS; Watermark Soil Moisture Sensors Model 200SS, Irrometer Co., Riverside, Calif., USA) at 0.2-m depth below onion and potato rows. Sensors were calibrated to SWP. The GMS were connected to a datalogger (CR10X datalogger, Campbell Scientific, Logan, Utah, USA) via five multiplexers (AM416 multiplexer, Campbell Scientific). The datalogger was programmed to read the GMS in each irrigation treatment zone 4 to 8 times a day and irrigate each zone individually as necessary. Irrigations were controlled by the datalogger signaling a controller (SDM-CD16AC controller, Campbell Scientific) connected to solenoid valves for each zone. The pressure in the drip lines was maintained at 69 kPa by a pressure regulator in each zone. The amount of water applied in each zone was recorded by a water meter installed between the solenoid valve and the drip tape. The irrigation criteria for onion (Allium cepa) and potato (Solanum tuberosum) were determined for subsurface drip irrigation (SDI). N fertilizer requirements may be reduced due to reduced N leaching under SDI.(Download PDF) (Export to EndNotes)