A Guide for Selecting Subsurface Drip Irrigation (SDI)Laterals in Field Crops

摘要

The technique of burying inexpensive drip tape and flat emitter dripline laterals beneath field crops such as cotton, corn and sugarcane with subsurface drip irrigation (SDI) systems was pioneered in the United States in the 1970's and is now rapidlybeing adopted because of its many benefits. Selecting the correct lateral model is integral for the successful adoption of SDI, but is often challenging because there are many lateral choices along with agronomic, hydraulic and economic considerations. Lateral choices include tape or flat emitter dripline with emitter flow rates from .07 gph to .53 gph, emitter spacing from 6 inches to 24 inches, internal diameters from 5/8 of an inch to 1 3/8 of an inch, and wall thicknesses from 4 mil (.004 inches) to15 mil (.015 inches). To help ease the selection process, an easy-to-use, four-step lateral selection guide was developed that uniquely translates soil, water, and crop information, and commonly used gpm/acre water availability information and/or inches/hour desired application rate information, into a range of lateral choices. In addition to the selection guide, Toro's AquaFlow drip irrigation design software is available to report the block emission uniformity (EU) as a result of lateral choices. Itis believed that by using both the SDI guide and AquaFlow software in the decision process, SDI lateral specification will be more effective for irrigation system designers.