Weather and soil in the US Midwest influence the effectiveness of single‐ and split‐nitrogen applications in corn production. (29th October 2020)

• Record Type: Journal Article
• Authors: Clark, Jason D.; Fernández, Fabián G.; Camberato, James J.; Carter, Paul R.; Ferguson, Richard B.; Franzen, David W.; Kitchen, Newell R.; Laboski, Carrie A. M.; Nafziger, Emerson D.; Sawyer, John E.; Shanahan, John F.
• Is Part Of: Agronomy Journal. Volume 112:Number 6(2020)
• Page Start: 5288
• Page End: 5299
• Publication Date: 2020-10-29
• Subjects: Agronomy -- Periodicals; 630
• DOI: 10.1002/agj2.20446
• Languages: English
• ISSNs: 0002-1962

Abstract

Abstract: Splitting the N application into two or more timings may improve corn ( Zea mays L.) grain yield and N recovery relative to a single‐N application. A 49 site‐year study across eight U.S. Midwestern states compared the effect of an at‐planting (single‐N application) and two split‐N applications [45 (45+SD) or 90 kg N ha −1 (90+SD) at planting with the remainder of the total rate (180 or 270 kg N ha −1 ) applied at V9]. For split‐N applications, soil and plant responses were similar between 45+SD and 90+SD 93–98% of the time, indicating the at‐planting N rate of 45 kg N ha −1 may be all that is needed in most cropping scenarios. Splitting the N application compared to a single‐N application changed soil NO3 –N at VT and post‐harvest <35% of the time and plant N uptake and grain yield <15% of the time. Split‐N applications had greater grain yield in areas with uniform precipitation around the sidedress timing (Shannon Diversity Index >0.56–0.59) to incorporate N in the root zone, and in coarse‐textured soil (sand content >4–10%) that had greater potential for N loss. Single‐N applications produced greater grain yield in soils with more total N (>2.1–2.4 g kg −1 ) to support N mineralization and greater cation exchange capacity (CEC) (> 27–31 cmolc kg −1 ), silt content (>66–74%), or clay content (>24–37%) to improve nutrient and water retention. Decisions on nitrogen application timing should be made based on soil parameters and typical weather conditions around the sidedress timing.