Subsurface drip irrigation (SDI) can substantially reduce the amount of irrigation water
needed for corn production. However, corn yields need to be improved to offset the initial cost of
drip installation. Air-injection is at least potentially applicable to the (SDI) system. However, the
vertical stream of emitted air moving above the emitter outlet directly toward the surface creates
a chimney effect, which should be avoided, and to ensure that there are adequate oxygen for root
respiration. A field study was conducted in 2010 and 2011, to evaluate the effect of air-injection into
the irrigation stream in SDI on the performance of corn. Experimental treatments were drip irriga-
tion (DI), SDI, and SDI with air injection. The leaf area per plant with air injected was 1.477 and
1.0045 times greater in the aerated treatment than in DI and SDI, respectively. Grain filling was
faster, and terminated earlier under air-injected drip system, than in DI. Root distribution, stem
diameter, plant height and number of grains per plant were noticed to be higher under air injection
than DI and SDI. Air injection had the highest water use efficiency (WUE) and irrigation water use
efficiency (IWUE) in both growing seasons; with values of 1.442 and 1.096 in 2010 and 1.463 and
1.112 in 2011 for WUE and IWUE respectively. In comparison with DI and SDI, the air injection
treatment achieved a significantly higher productivity through the two seasons. Yield increases due
to air injection were 37.78% and 12.27% greater in 2010 and 38.46% and 12.5% in 2011 compared
to the DI and SDI treatments, respectively. Data from this study indicate that corn yield can be
improved under SDI if the drip water is aerated.
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