Evaluation of two irrigation scheduling methods and nitrogen rates on corn production in Alabama

Authors: DA CUNHA LEME FILHO, JOSE - Virginia Tech; ORTIZ, BRENDA - Auburn University; Balkcom, Kipling; DAMIANIDIS, DAMIANOS - Estacion Experimental Agroindustrial Obispo Colombres (EEAOC); DOUGHERTY, MARK - Auburn University

Submitted to: International Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2020
Publication Date: 9/15/2020
Citation: Da Cunha Leme Filho, J.F., Ortiz, B.V., Balkcom, K.S., Damianidis, D., Dougherty, M. 2020. Evaluation of two irrigation scheduling methods and nitrogen rates on corn production in Alabama. International Journal of Agronomy. Volume 2020, Article ID: 8869383, 13 pp. https://doi.org/10.1155/2020/8869383.
DOI: https://doi.org/10.1155/2020/8869383

Interpretive Summary: Regulations on nutrient application amounts and environmental impacts of fertilizers are promoting advances in agricultural management strategies to optimize irrigation application and N fertilization in corn. Previous studies have found a relationship between irrigation application, available water in the soil, and N fertilizer uptake. Scientists at Virgina Tech Univ, Auburn Univ. and USDA-ARS (Auburn, AL) evaluated interactions between two irrigation scheduling methods and four N rate applications (0-control, 202, 269, and 336'kg'ha-1) on grain yield, aboveground biomass, plant N concentration, N uptake, and nitrogen use efficiency (NUE) in corn for two growing seasons (2014 and 2015) in north Alabama. Irrigation amounts from both irrigation scheduling methods indicated that less water was applied with the sensor-based method compared to pan evaporation. Although different irrigation amounts were applied between irrigation scheduling methods, water amounts did not impact grain yield, aboveground biomass, and NUE. The lack of differences may be attributed to low irrigation amounts applied. In general, NUE values decreased with increased N rates, which means more applied N remained in the soil, increasing risk for environmental problems. Despite the lack of differences between irrigation methods, the sensor-based method was proven as a reliable method to monitor soil water status and provide useful data for producers to manage irrigation scheduling.

Technical Abstract: Regulations on nutrient application amounts and environmental impacts of fertilizers are promoting advances in agricultural management strategies to optimize irrigation application and N fertilization in corn. Previous studies have found a relationship between irrigation application, available water in the soil, and N fertilizer uptake. The objective of this study was to evaluate interactions between two irrigation scheduling methods and four N rate applications (0-control, 202, 269, and 336'kg'ha-1) on grain yield, aboveground biomass, plant N concentration, N uptake, and nitrogen use efficiency in corn. The study was conducted at the Tennessee Valley Research and Extension Center (TVREC) during two growing seasons (2014 and 2015). The irrigation scheduling methods consisted of (i) the pan evaporation method, which is based on managing the crop’s estimated evapotranspiration (ET) using pan evaporation values and the crop’s consumptive water use and (ii) the sensor-based irrigation scheduling method based on soil matric potential values recorded by soil moisture tension sensors installed in the field. Irrigation amounts from both irrigation scheduling methods indicated that less water was applied with the sensor-based method. The different amounts of irrigation applied associated with the two irrigation scheduling methods did not impact grain yield, aboveground biomass, and NUE. In general, NUEs values decreased with increased N rates, which means that additional N fertilizer added to the soil was not converted into grain yield or/and adsorbed by plants; therefore, more N remained in the soil, increasing the risk for environmental problems.