title: Fertilizer residence time affects nitrogen uptake efficiency and growth of sweet corn.
abstract: Understanding plant N uptake dynamics is critical for increasing fertilizer N uptake efficiency (FUE) and minimize the risk of N leaching. The objective of this research was to determine the effect of residence time of N fertilizer on N uptake and FUE of sweet corn. Plants were grown in 25 L columns during the fall and spring to mimic short-term N uptake dynamics. Nitrogen was applied either 1, 3, or 7 d before a weekly leaching event, using KNO3 solution (total of 393 kg N ha(-1)). Residence times (tR) were tR-1, tR-3, and tR-7 d before weekly removal of residual soil N. Plant N uptake was calculated by comparing weekly N recovery from planted with non-planted columns. During the fall, N uptake values at 70 d after emergence were 59, 73, and 126 kg N ha(-1). During the spring, corresponding values were 54, 108, and 159 kg N ha(-1). A linear response of plant growth and yield to the tR was observed under cooler conditions, whereas a quadratic response occurred under warmer conditions. There was correlation between root length density and yield. It is concluded that increasing N fertilizer residence time, which is indicative of better irrigation practices, enhanced overall sweet corn growth, yield, N uptake, and FUE, consequently reduced the risk of N being leached below the root zone before complete N uptake.
authors.affiliation: Univ. of Florida, IFAS, Agricultural and Biological Engineering Dep., 234 Fraziers-Rogers Hall, Gainesville, FL 32611-0570, USA. lzota@ufl.edu
authors.forename: L
authors.initials: L
authors.lastname: Zotarelli
authors.forename: J M
authors.initials: JM
authors.lastname: Scholberg
authors.forename: M D
authors.initials: MD
authors.lastname: Dukes
authors.forename: R
authors.initials: R
authors.lastname: Muñoz-Carpena
mesh_terms: D002980:Climate; D018556:Crops, Agricultural / Q000254:growth & development / Q000378:metabolism; D005308:Fertilizers; D009584:Nitrogen / Q000378:metabolism*; D014867:Water; D003313:Zea mays / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D014867:Water; D009584:Nitrogen