1、Corn optimum nitrogen fertilizer rate and application timing when

To determine the effects of RCC and N fertilizer application timing on corn yield response to N fertilizer rate we used a mixed-effects quadratic-plateau model.

2、Understanding N timing in corn yield and fertilizer N recovery: An

However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15 N isotope.

3、Corn Nitrogen Timing

To optimize uptake of nitrogen (N) fertilizer eficiency and to minimize the adverse impact of N on the environment, we recommend that N be applied at the right time, in the right form, at the right place, and in the right amount. This chapter specifically addresses applying N at the right time.

How Long Does It Take For Nitrogen Fertilizer To Work

Nitrogen fertilizer activates within 24-48 hours, with effects becoming more noticeable after 7-14 days. Its importance in plant growth is clear, but timing is vital for effective agricultural practices.

Nitrogen Application Timing in Corn Production

Applying N at multiple times, including the time of maximum crop uptake, can spread the risk of N loss and crop deficiency, improve profitability by reducing N rates, and benefit the environment. This Crop Insights discusses timing N applications to corn.

Timing and Other Considerations of Nitrogen Application in Corn

Generally UNL does not recommend fall N fertilizer applications in corn. Research has shown that fall applications of N fertilizer are less efficient than applications during the growing season. Corn uses N more efficiently when applied as close as possible to when the plant needs it.

Impacts of Nitrogen Fertilizer Application Timing and Rate on Sweet

This study evaluates the effects of several N rates (ranging from 224 to 336 kg ha−1) and N fertilizer application timing (N fertilizer applied at emergence and side-dress stages) on sweet corn growth and yield under the subtropical environmental conditions of the southeastern US.

What is the Perfect Nitrogen Rate for Corn?

Corn farmers always seem to be searching for that perfect nitrogen (N) application rate, probably because it can be a moving target. Apply too little, and you miss out on yield potential.

How Late

Late-season nitrogen can impact kernel number, weight, and grain fill — see how timing and hybrid choice influence final corn yield.

Does nitrogen application rate affect the moisture content of corn

Nitrogen fertilizer application is an important measure to obtain high and stable corn yield, and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting.

The effectiveness of nitrogen fertilizer in corn topdressing refers to the impact on corn growth after the fertilizer is absorbed by plants from the soil. Nitrogen is an essential nutrient for plant growth and development, critical for the growth of corn leaves, stems, and roots. Below is a detailed explanation of the manifestations and influencing factors of nitrogen fertilizer efficacy:

I. Characteristics of Nitrogen Fertilizer Efficacy

1. Rapid Effectiveness: After application, nitrogen fertilizers can be quickly absorbed by plant roots and converted into ammonium nitrogen in a short time, supplying nitrogen for photosynthesis in corn leaves. Thus, nitrogen fertilizers exhibit distinct quick-acting properties.
2. Growth Promotion: Nitrogen fertilizers promote corn plant growth, especially during the seedling and jointing stages. Appropriate nitrogen application significantly enhances growth rates and biomass.
3. Quality Impact: While nitrogen boosts growth, excessive use reduces corn quality, such as smaller kernels and lower starch content.
4. Stress Resistance: Long-term heavy nitrogen application weakens disease resistance, making corn more susceptible to pests and diseases.
5. Soil Structure Impact: Excessive nitrogen leads to soil compaction, reducing透气性（aeration）and water permeability, which disrupts normal corn growth.

II. Timing and Methods of Application

1. Topdressing Timing: Nitrogen should be applied based on corn growth stages. The critical period is from jointing to tasseling (when plants reach 30–60 cm tall). Topdressing during this stage effectively promotes growth.
2. Application Methods: Nitrogen can be applied as basal fertilizer (before planting), seed fertilizer (immediately after planting), or topdressing (during growth). Different methods yield varying effects.
3. Dosage: The amount depends on corn requirements and soil fertility. Generally, topdressing should not exceed 10 kg of urea per mu (approx. 0.067 hectares).

III. Factors Affecting Nitrogen Efficacy

1. Soil Conditions: Soil pH, organic matter, and structure influence efficacy. In acidic soils, ammonium nitrogen may convert to ammonia gas (losing availability), while alkaline soils favor nitrate absorption. Organic matter improves soil structure and nutrient uptake.
2. Climate: High temperatures and drought reduce nitrogen absorption due to insufficient soil moisture, while rainy conditions cause nutrient runoff.
3. Corn Varieties: Different breeds have varying nitrogen demands. High-yield varieties may require less nitrogen, while stress-tolerant types need more.
4. Application Methods: Deep application ensures even distribution and absorption, while spot application minimizes loss and maximizes efficiency.

IV. Recommendations and Precautions

1. Rational Application: Tailor dosage and timing to corn needs and soil fertility. Avoid overapplication or blind topdressing.
2. Combine with Organic Fertilizers: Pair nitrogen fertilizers with organic matter to improve soil health and fertility.
3. Crop Rotation: Avoid continuous corn planting to prevent soil nutrient depletion and degradation.
4. Safety Measures: Handle nitrogen fertilizers carefully to avoid skin contact, and prevent spillage near crops or water sources.

proper nitrogen application accelerates corn growth, but dosage and timing must be controlled to avoid quality losses and soil issues. Scientific management and rational practices ensure stable, high-quality yields.