Optimized strategies for maize production under limited irrigation capacities

Authors: Schwartz, Robert; BELL, JOURDAN - Texas A&M Agrilife; Baumhardt, Roland - Louis; Colaizzi, Paul

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/28/2019
Publication Date: 11/12/2019
Citation: Schwartz, R.C., Bell, J.M., Baumhardt, R.L., Colaizzi, P.D. 2019. Optimized strategies for maize production under limited irrigation capacities [abstract]. ASA-CSSA-SSSA Annual International Meeting, November 11-13, 2019, San Antonio, Texas. Poster session 350, poster no. 1372.

Interpretive Summary:

Technical Abstract: Maize production in the semiarid High Plains of Texas often suffers from exceptional yield reductions because irrigation cannot meet the seasonal and peak water requirements. Under limited irrigation, maize (Zea Mays L.) production risks may be ameliorated by reducing the irrigated acreage, optimizing plant population, and using hybrids better adapted to water stress. We examined the effect of irrigation and plant population during three growing seasons on grain yield and yield components of three maize cultivars, two of which were labeled as drought tolerant. Overhead sprinkler irrigation was based on prescribed application rates of 25.4 mm every third (high) or sixth (low) day unless stored soil water exceeded 85% of plant available water at field capacity. Maize was planted to achieve two populations that averaged 6.4 (low) and 8.9 plants m-2 (high). Crop water use was based on change in soil water contents measured by a neutron moisture probe and accumulated precipitation and irrigation. Seasonal crop water use averaged 748 and 595 mm across years for the high and low irrigation levels, respectively. Mean grain yields varied from 5.3 Mg/ha in 2016 under the low irrigation rate to 19.9 Mg/ha at the high irrigation rate in 2018. Cultivar did not influence grain yields and aboveground biomass in all three growing seasons. In 2016, grain yield was not significantly influenced by plant population at the high irrigation level (P=0.697). However, at the low irrigation level and under considerable water stress, grain yields were significantly lower at the high plant population (P<0.001). The steep grain yield response of corn to water use implies that in some years concentrating irrigation on half the acreage would generate greater total harvested yield. Simulations of long-term maize yield response to water use are required to determine the optimum irrigation capacity that maximizes profit for the region.