1、Optimal rate of nitrogen fertilizer improves maize grain yield by

Optimal nitrogen fertilization improved grain yield by delaying the onset of senescence of ear leaves and altering its RemN, thus impacting grain filling.

2、Nitrogen Supply Affects Yield and Grain Filling of Maize by Regulating

This study aimed to examine the effect of nitrogen (N) application rate and time on yield, grain filling, starch metabolizing enzymes, and hormones of maize based on a long-term field experiment initiated in 2012.

3、Nitrogen fertilizer application rate affects the dynamic metabolism of

Conclusion: Collectively, our findings underscore the critical role of N in regulating kernel N and C metabolism, thereby influencing dry matter accumulation in waxy maize grains during the grain filling stage.

4、Effects of Nitrogen Application Strategies on Yield, Nitrogen Uptake

In this study, a field plot trial with five N fertilization application strategies was conducted in the maize field from 2021 to 2022 in the Ningxia Yellow Irrigation District, Northwest China.

5、Nitrogen application affects maize grain filling by regulating grain

Grain water relations play an important role in grain filling in maize. The study aimed to gain a clear understanding of the changes in grain dry weight and water relations in maize grains by using hybrids with contrasting nitrogen efficiencies under differing nitrogen levels.

Nitrogen fertilizer application rate affects the dynamic metabolism of

Collectively, our findings underscore the critical role of N in regulating kernel N and C metabolism, thereby influencing dry matter accumulation in waxy maize grains during the grain filling stage.

Optimizing N applications increases maize yield and reduces

Maize plays a crucial role in global food security, while extensive use of nitrogen (N) fertilizers in maize production has posed severe environmental risks.

Nitrogen Supply Affects Yield and Grain Filling of Maize by Regulating

This research aimed to examine the effect of nitrogen (N) application rate and time on yield, grain filling, starch metabolizing enzymes, and hormones of mai...

Reducing soil nitrogen losses from fertilizer use in global maize and

Maize and wheat are two major staple foods that collectively contribute two-thirds of the world’s grain supply. The extensive use of nitrogen (N) fertilizers during the cultivation of both...

Nitrogen fertilization affects maize grain yield through regulating

In the past four decades, global maize production has greatly increased (FAO, 2018) mainly due to application of nitrogen (N) fertilizers. Worldwide, N fertilizer has widely been excessively applied to achieve higher grain yields (Cui et al., 2009; Meng et al., 2016; Liang et al., 2020).

Whether nitrogen fertilizer is required after the maize grain-filling stage depends on multiple factors, including crop growth stages, soil conditions, climatic environments, and specific agricultural management practices. Below is a detailed analysis of the necessity of nitrogen fertilizer during this period:

I. Definition and Importance of the Maize Grain-Filling Stage

1. Definition of the Grain-Filling Stage: The grain-filling stage is a critical period when maize transitions from vegetative to reproductive growth. During this phase, the plant absorbs water and nutrients through its root system to provide essential energy and hormonal support for ear development and kernel formation.

2. Importance: Proper management during the grain-filling stage is vital for improving maize yield and quality. Optimized conditions ensure sufficient nutrient supply to the ears, preventing issues like bare tips, weak kernels, or uneven grain development.

II. The Role and Demand for Nitrogen Fertilizer

1. Function of Nitrogen: Nitrogen is a key component of proteins and is essential for the growth and development of grasses like maize. Nitrogen fertilizer promotes leaf growth, enhances photosynthetic efficiency, and provides the necessary nutrients for the plant.

2. Nitrogen Demand: During the grain-filling stage, maize requires significant nitrogen to support ear development and kernel formation. Appropriate nitrogen application ensures adequate nutrient supply, facilitating healthy growth.

III. Necessity of Nitrogen Fertilizer After Grain Filling

1. Critical Role of Nitrogen: Nitrogen remains indispensable during the grain-filling stage. It supports leaf growth, photosynthesis, and kernel development. Thus, proper nitrogen application is crucial at this stage.

2. Risks of Excessive Application: overapplication can lead to excessive vegetative growth, resulting in weak, easily lodged stalks. Excess nitrogen may also reduce kernel quality, causing irregular sizes, discoloration, or poor protein content.

3. Recommended Practices:

   • Dosage: Apply 5–10 kg of urea per mu (approx. 0.067 hectare) based on soil tests and crop conditions.
   • Fertilization Strategies: Combine nitrogen with other nutrients (e.g., phosphorus, potassium) to ensure balanced nutrition.

4. Timing and Methods:

   • Apply fertilizer in the morning or evening to minimize volatilization.
   • Use deep placement or hole application to distribute nutrients evenly around the roots for better absorption.

IV. Other Influencing Factors

1. Soil Conditions:

   • Soil pH, organic matter, and structure affect nitrogen availability. For example, acidic soils may reduce nitrogen uptake efficiency.

2. Climate:

   • Temperature and precipitation impact maize growth. Drought or extreme heat can hinder nitrogen absorption, while excessive rain may leach nutrients. Adjust irrigation and fertilization accordingly.

3. Pest and Disease Management:

   • Pests and diseases can deplete plant nutrients, disrupting the grain-filling process. Integrate pest control with fertilization to maintain plant health.

The need for nitrogen fertilizer after the maize grain-filling stage depends on crop stage, soil properties, climate, and management practices. Proper nitrogen application during this period boosts yields and kernel quality. excessive use poses risks, so dosage and timing should be adjusted based on specific conditions.