Short-statured maize achieved similar growth and nitrogen uptake but greater nitrogen efficiencies than conventional tall maize

Abstract

Despite a historical favoring of robust tall plants in maize (Zea mays L.) production systems as a potential indicator of increased total and/or grain biomass yields, short-statured maize is receiving renewed commercial attention in North America. Little is known of the relative N efficiencies resulting from potential inter-stature differences in dry matter formation and N processes during pre- and post-silking stages. To investigate this, two field rainfed experiments were conducted in West Lafayette, IN. The experiments included factorial combinations of two tall- and two short-statured maize hybrids subjected to three N rates: 0 (unfertilized), 168 (moderate), and 224 kg N ha⁻¹ (elevated) applied at planting. Short hybrids with a 25% reduced stature showed no statistically significant differences in seasonal biomass accumulation and N uptake, or in biomass partitioning to grain (harvest index) versus stover at maturity relative to conventional tall hybrids. Increased leaf biomass and ear growth at silking, plus comparable quantities of N remobilization from stems during grain filling, with short-stature maize contributed to its grain yield parity with tall-stature maize. Additionally, our research revealed other noteworthy findings: short-statured maize had higher N harvest index and N recovery efficiency than the tall maize, implying more N status resiliency at moderate N rates. The lack of interactions between N × stature in most studied traits suggests that short hybrids can perform at least as well as conventional tall hybrids across a range of N rates. Our findings provide insights for fine-tuning of breeding and management programs.