Author
Sigua, Gilbert | |
Stone, Kenneth | |
Bauer, Philip | |
Szogi, Ariel |
Submitted to: WIT Transactions on Ecology and the Environment
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/10/2016 Publication Date: 7/6/2016 Citation: Sigua, G.C., Stone, K.C., Bauer, P.J., Szogi, A.A. 2016. Nitrate leaching, water-use efficiency and yield of corn with different irrigation and nitrogen management systems in coastal plains, USA. WIT Transactions on Ecology and the Environment. 203:159-170. https://doi.org/10.2495/EID160151. DOI: https://doi.org/10.2495/EID160151 Interpretive Summary: Adequate supply of water and nutrients results in higher water and nutrient use efficiency, better crop production control and avoidance of stress conditions. Irrigation management for corn (Zea mays L.) production on the typical low water holding capacity soil of the southeastern USA needs to be improved to increase irrigation efficiency and reduce losses of nitrate from fields. A three-year (2012-2014) field study was conducted to compare the effects of three irrigation scheduling methods: Irrigator Pro (IPRO); Normalized Difference Vegetative Index (NDVI) and Soil Water Potentials (SWP) and two levels of nitrogen (N) (157 and 224 kilogram N per hectare (kg N ha-1) on nitrate level, water-use, and yield of corn grown on four soil types in the Coastal Plains, USA. Yield of corn were not affected by irrigation methods or soil types. Both yield and water-use efficiency (WUE) of corn differed among years. Average yields and WUE were 15.6, 10.5 and 13.5 Mg ha-1 and 29.8, 16.8 and 23.8 kilogram grain per hectare per millimeter (kg grain ha-1 mm-1) in 2012, 2013 and 2014, respectively. Leached nitrate varied significantly with irrigation and N management systems, but not with soil types. The IPRO method had the lowest concentration of nitrate (11.1 mg L-1) followed by SWP (16.5 milligram per liter (mg L-1) and NDVI (17.9 mg L-1). The low N application rate resulted in lower nitrate concentration (13.4 mg L-1) than the high N rate (17.0 mg L-1). Irrigator PRO can have the advantage of minimizing the amount of NO3 being leached during irrigation when compared with NDVI and SWP. Our results suggest that each irrigation method was able to adequately manage irrigation to produce adequate corn yields for the region. Since the IPRO method resulted in lower nitrate concentration in the lysimeters, the results indicate scheduling method may be a way to reduce fertilizer N losses to leaching on these soils. Technical Abstract: Irrigation management for corn (Zea mays L.) production on the typical low water holding capacity soil of the southeastern USA needs to be improved to increase irrigation efficiency and reduce losses of nitrate from fields. A three-year (2012-2014) field study was conducted to compare the effects of three irrigation scheduling methods: Irrigator Pro (IPRO); Normalized Difference Vegetative Index (NDVI) and Soil Water Potentials (SWP) and two levels of nitrogen (N) (157 and 224 kilogram N per hectare (kg N ha-1) on nitrate level, water-use, and yield of corn grown on four soil types in the Coastal Plains, USA. Yield of corn were not affected by irrigation methods or soil types. Both yield and water-use efficiency (WUE) of corn differed among years. Average yields and WUE were 15.6, 10.5 and 13.5 Mg ha-1 and 29.8, 16.8 and 23.8 kilogram grain per hectare per millimeter (kg grain ha-1 mm-1) in 2012, 2013 and 2014, respectively. Leached nitrate varied significantly with irrigation and N management systems, but not with soil types. The IPRO method had the lowest concentration of nitrate (11.1 mg L-1) followed by SWP (16.5 milligram per liter (mg L-1) and NDVI (17.9 mg L-1). The low N application rate resulted in lower nitrate concentration (13.4 mg L-1) than the high N rate (17.0 mg L-1). Our results suggest that each irrigation method was able to adequately manage irrigation to produce adequate corn yields for the region. Since the IPRO method resulted in lower nitrate concentration in the lysimeters, the results indicate scheduling method may be a way to reduce fertilizer N losses to leaching on these soils. |