Effects of nitrogen application stage on grain yield and nitrogen use efficiency of high-yield summer maize

Abstract

This study aims to explore the optimum nitrogen (N) application method by analyzing effects of variable N application stages and ratios on the N absorption and translocation of high-yield summer maize (DH661). Te study included field experiments and 15N isotopic dilutions for pot experiments. Results showed that the yield was not increased in a one-off N application at the jointing stage. Te uptake of fertilizer-derived N in the grain increased with the increasing of N applied times. Compared to a single or double application, total N uptake (Nup) and bio-mass increased significantly by supplying N at the six-leaf stage (V6), ten-leaf stage (V10) and 10 days after anthesis in ratios of 3:5:2 and 2:4:4. Te fertilizer-derived recovery rates were 67.5% and 78.1%, respectively. Te uptake and utilization of fertilizer-derived N was enhanced by increasing the recovery rate of N supplied after anthesis, and reducing the absorption of soil-derived N. Therefore, the 2:4:4 application ratios was the optimal N application method.