Stand Age Affects Fertilizer Nitrogen Response in First‐Year Corn following Alfalfa. (1st March 2015)

• Record Type: Journal Article
• Authors: Yost, Matt A.; Russelle, Michael P.; Coulter, Jeffrey A.; Schmitt, Michael A.; Sheaffer, Craig C.; Randall, Gyles W.
• Is Part Of: Agronomy Journal. Volume 107:Number 2(2015)
• Page Start: 486
• Page End: 494
• Publication Date: 2015-03-01
• Subjects: Agronomy -- Periodicals; 630
• DOI: 10.2134/agronj14.0493
• Languages: English
• ISSNs: 0002-1962

Abstract

Abstract : Knowledge about how stand age affects N response in first‐year corn ( Zea mays L.) following alfalfa ( Medicago sativa L.) is needed to improve N credit predictions. In a 3‐yr study, we evaluated response to N in first‐year corn following fall‐terminated 1‐ to 3‐yr‐old alfalfa stands with stand densities of 33 to 579 plants m −2 at Lamberton and Waseca, MN, each year. At both locations, alfalfa stand age had minor impacts on soil inorganic N content and aboveground corn dry matter (DM) yield, N concentration, and N uptake during first‐year corn. On medium‐textured soil at Lamberton, first‐year corn following 3‐yr‐old alfalfa stands required no fertilizer N to economically optimize grain yield, but required 64 and 97 kg N ha −1 following 2‐ and 1‐yr‐old stands, respectively, at the fertilizer cost (US$ kg −1 N)/corn grain price ($ kg −1 grain) ratio of 5.6. At the same price ratio on fine‐textured soil at Waseca, first‐year corn required 94 kg N ha −1 following both 2‐ and 3‐yr‐old stands and 118 kg N ha −1 following 1‐yr‐old stands. Therefore, current alfalfa N credit guidelines from land‐grant universities that are based on alfalfa stand density at termination were not accurate for alfalfa stands ≤3 yr old that frequently had high densities. These results also confirm that alfalfa stand age affects the frequency and level of fertilizer N response in first‐year corn, and support the role of soil texture in altering the effect of stand age.