TY - JOUR

T1 - Mixture of controlled-release and normal urea to improve maize root development, post-silking plant growth, and grain filling

AU - Zheng, Chunyu

AU - Li, Chunlin

AU - Tian, Longbing

AU - Shen, Zhaoyin

AU - Feng, Guozhong

AU - Hou, Wenfeng

AU - Liu, Fulai

AU - Gao, Qiang

AU - Wang, Yin

PY - 2023

Y1 - 2023

N2 - The mixture of controlled-release urea (CRU) and normal urea (MCU) applied as one-time basal fertilizer is a convenient and effective alternative to traditional split-nitrogen (N) fertilization, can ensure a sufficient late-season N supply to increase maize yield. However, the effects of MCU ratios on maize root development, post-silking growth, and grain-filling process remain poorly understood. In this study, 3-year field experiments were conducted on sandy and clay soils in Northeast China, to evaluate maize yield responses to different MCU ratios (from 0% to 60% at 15% intervals). Four key treatments, i.e., N omission (N0), MCU0%, MCU30%, and MCU60%, were then selected to investigate root traits, post-silking plant growth and N uptake, grain-filling parameters, and their relationships with grain yields. Across different soils and years, grain yields showed a parabolic curve with increasing MCU ratios, with the highest yields obtained in MCU30%. On average, MCU30% increased grain yield by 22.3% and 11.7% on sandy and clay soils, respectively, relative to MCU0%. The appropriate early-N supply in MCU30% promoted root growth by allocating more dry matter (DM) to roots, while increasing total root length by producing more and longer crown roots, as well as higher lateral root length. The well-developed roots in MCU30% increased post-silking plant N uptake under sufficient late-N supply, thereby delayed leaf senescence and improved DM production for grain-filling, ultimately increased kernel weight and grain yield. Compared to MCU30%, MCU60% showed similar growth and yield performances on clay soil. In contrast, MCU60% performed notably worse on sandy soil due to limited CRU-N release at early period under inherently lower soil moisture and fertility levels. Our measurements and correlation analysis support the conclusion that MCU30% effectively sustain leaf longevity and increase post-silking DM by optimizing root growth and morphology under an optimal N supply pattern during maize growing season, thus improving grain-filling and final yield. The results advance our understanding of how MCU method affects maize post-silking growth and yield formation, providing important insights for optimizing crop N management by regulating root development, especially on lower fertility soils.

AB - The mixture of controlled-release urea (CRU) and normal urea (MCU) applied as one-time basal fertilizer is a convenient and effective alternative to traditional split-nitrogen (N) fertilization, can ensure a sufficient late-season N supply to increase maize yield. However, the effects of MCU ratios on maize root development, post-silking growth, and grain-filling process remain poorly understood. In this study, 3-year field experiments were conducted on sandy and clay soils in Northeast China, to evaluate maize yield responses to different MCU ratios (from 0% to 60% at 15% intervals). Four key treatments, i.e., N omission (N0), MCU0%, MCU30%, and MCU60%, were then selected to investigate root traits, post-silking plant growth and N uptake, grain-filling parameters, and their relationships with grain yields. Across different soils and years, grain yields showed a parabolic curve with increasing MCU ratios, with the highest yields obtained in MCU30%. On average, MCU30% increased grain yield by 22.3% and 11.7% on sandy and clay soils, respectively, relative to MCU0%. The appropriate early-N supply in MCU30% promoted root growth by allocating more dry matter (DM) to roots, while increasing total root length by producing more and longer crown roots, as well as higher lateral root length. The well-developed roots in MCU30% increased post-silking plant N uptake under sufficient late-N supply, thereby delayed leaf senescence and improved DM production for grain-filling, ultimately increased kernel weight and grain yield. Compared to MCU30%, MCU60% showed similar growth and yield performances on clay soil. In contrast, MCU60% performed notably worse on sandy soil due to limited CRU-N release at early period under inherently lower soil moisture and fertility levels. Our measurements and correlation analysis support the conclusion that MCU30% effectively sustain leaf longevity and increase post-silking DM by optimizing root growth and morphology under an optimal N supply pattern during maize growing season, thus improving grain-filling and final yield. The results advance our understanding of how MCU method affects maize post-silking growth and yield formation, providing important insights for optimizing crop N management by regulating root development, especially on lower fertility soils.

KW - Controlled-release urea

KW - Maize yield

KW - Root morphology

KW - Grain filling

KW - Post-silking growth

U2 - 10.1016/j.eja.2023.126994

DO - 10.1016/j.eja.2023.126994

M3 - Journal article

VL - 151

JO - European Journal of Agronomy

JF - European Journal of Agronomy

SN - 1161-0301

M1 - 126994

ER -