Differences in dry matter production and grain yield of maize (Zea mays L.) cultivars with contrasting nitrogen efficiency

Abstract

ABSTRACT We aimed to investigate the differences in dry matter accumulation (DMA), distribution, remobilisation, and yield of maize cultivars with contrasting nitrogen efficiency responses to nitrogen application rates. Nitrogen fertiliser increased DMA, crop growth rate (CGR), redistribution of pre-silking dry matter, and accumulation of post-silking dry matter while reducing the root/shoot biomass ratio to substantially increase biomass yield and final maize grain yield. Higher final theoretical biomass yield, maximum increasing rate (MIR), and average increasing rate, later days to MIR, longer duration of rapid growth period, higher ratio of vegetative organs, and rational dry matter distribution aboveground and belowground contribute to higher DMA and CGR in the later growth stage, and higher assimilated dry matter into grain and biomass yield to finally obtain higher grain yield for N-efficient maize cultivar. The N-efficient cultivar had obvious advantages on grain yield compared with N-inefficient cultivar caused by higher dry matter average increasing rate and biomass and kernels per ear, while the advantages increased first, then decreased with higher N rates, and the highest value was observed at 247.5 kg N ha−1. Therefore, selecting N-efficient maize improves maize yield per unit area while reducing N fertiliser supply, especially at low N application rates.