Corn production under restricted irrigation in the Texas High Plains
2020
Thāpā, Sushīl | Xue, Qingwu | Marek, Thomas H. | Xu, Wenwei | Porter, Dana | Jessup, Kirk E.
Sustainable corn (Zea mays L.) production in the semiarid Texas High Plains (THP) relies on irrigation water from the Ogallala Aquifer, but it is well known that the aquifer is declining. A 3‐yr (2010–2012) field study was conducted to find whether successful corn production is possible using only 60% (300 mm) of the current average irrigation for the region (500 mm). Three corn hybrids (Pioneer P31G96, Pioneer P33D49, and Monsanto DKC67‐87) were planted at four densities (5, 6, 7, and 8 plants m⁻²) under a center pivot sprinkler system. Seasonal precipitation was highest in 2010 (224 mm), followed by 2012 (132 mm), and 2011 (85 mm). Seasonal evapotranspiration for corn ranged between 426 and 635 mm. Yield was significantly lower in 2011 (2.4 Mg ha⁻¹) and 2012 (6.0 Mg ha⁻¹) than 2010 (13.3 Mg ha‐¹) due to severe drought conditions combined with unusually high temperatures in those years. Increase in planting density increased biomass at silking but did not increase yield. Grain yield was related to biomass at maturity, harvest index, and biomass increase during grain filling. Results suggest that corn yields of about 13 Mg ha⁻¹ are possible with only 300 mm of irrigation in the THP, but production risk is high due to frequent years with low seasonal precipitation.
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