1、Effect of topdressing time on spring maize yield and nitrogen

To determine the optimum topdressing time for spring maize in the black soil of northeast China in the “one base and one topdressing” mode, the effects of topdressing time of nitrogen...

2、Appropriate nitrogen application rate with decreased basal/topdressing

Appropriate nitrogen application rate with decreased basal/topdressing ratio improves yield, quality, water productivity, and N-use efficiency of forage maize in a rainfed region

3、Post

Nitrogen is pivotal for high-yield maize (Zea mays L.), but excessive nitrogen application and improper timing remain common in production. Clarifying nitrogen strategies and population nitrogen accumulation under high density is urgent.

4、Postponed nitrogen fertilizer topdressing enhances nitrogen use

These findings demonstrated that postponed N fertilizer topdressing was an effective strategy in increasing yield and nitrogen use efficiency. The yield advantage of intercropping was the consequences of coordinated regulation interspecific competition, facilitation, and recovery (Li et al. 2001a).

5、Optimal Timing for Applying Fast

This article provides a comprehensive guide on when to apply nitrogen fertilizer, covering the importance of nitrogen, factors affecting its application, optimal timing, and benefits of timely application.

Rescheduling fertilizer nitrogen topdressing timings for improving

Rescheduling fertilizer nitrogen topdressing timings for improving productivity and mitigating N2O emissions in timely and late sown irrigated wheat (Triticum aestivum L.)

Effect of topdressing time on spring maize yield and nitrogen

Since the base fertilizer was applied to the soil when the maize was sown, the residual amounts of base fertilizer in different soil depths reflect the effect of different nitrogen application timings on the transport of nitrogen fertilizer.

Frontiers

It is uncertain whether adjusting the timing of N fertilizer topdressing to match the growth and development characteristics of the plant will cause improved yield, NUE, and rice quality compared with the basal application of a controlled-release fertilizer.

Scheduling of nitrogen fertilizer topdressing during panicle

We studied the impacts of timing of nitrogen fertilizer application during PF on photosynthesis and yield-related agronomic traits in ‘Y-Liang-You 900’ and ‘Y-Liang-You 6’, which are...

Rescheduling fertilizer nitrogen topdressing timings for improvin

The spectral properties recorded with PAU-LCC and SPAD meter at Zadoks 29 growth stage governed the grain yield response to fertilizer N application and can be used to fine-tune fertilizer N topdressing decisions over a wide range of varieties, locations, sowing timings and environments.

Topdressing nitrogen fertilizer is a common practice in agricultural production aimed at replenishing soil nitrogen to promote plant growth. Nitrogen is crucial for plants as it is a key component of proteins, chlorophyll, and other essential substances. Selecting the optimal timing for nitrogen application is critical to improving fertilizer utilization and crop yields.

I. Determining the Optimal Timing for Topdressing Nitrogen Fertilizer

1. Crop Growth Stages: The best time for topdressing nitrogen typically coincides with critical growth stages, such as the jointing, heading, flowering, and fruit expansion periods. During these phases, plants have peak nitrogen demands. Timely application ensures sufficient soil nitrogen to support rapid growth.

2. Soil Conditions: Soil texture, structure, and fertility influence application timing. For example:

   • Sandy soils (poor water retention) require prompt irrigation after fertilization to prevent root rot.
   • Clay soils (high water retention) need avoidance of excessive moisture to reduce root disease risks. Soil analysis should guide timing adjustments.

3. Climatic Conditions: Weather impacts nitrogen absorption:

   • Hot, humid seasons: Plants absorb nitrogen less efficiently, risking fertilizer waste.
   • Dry seasons: Nitrogen application can enhance drought resistance by improving water uptake. Adjust strategies based on local climate patterns.

II. Methods and Techniques for Topdressing Nitrogen

1. Uniform Broadcasting: Apply fertilizer evenly around plants to ensure soil contact. Avoid direct contact with stems or leaves to prevent burning or contamination.

2. Moderate Dosing: Follow the "small amounts, frequent applications" principle. Excessive nitrogen can burn roots; adjust dosages based on crop stage and soil conditions.

3. Deep Placement and Soil Covering: Bury fertilizer in soil to enable slow release, reducing nutrient loss. Covering soil minimizes stem irritation and improves absorption.

4. Combine with Irrigation: Irrigate promptly after application to maintain soil moisture, aiding fertilizer dissolution and nitrogen uptake. This also reduces runoff and evaporation losses.

5. Monitor Crop Response: Observe plant health post-application. Reduce nitrogen if excessive growth occurs; adjust strategies if stress or disease arise. Responsive management optimizes outcomes.

III. Post-Application Management Practices

1. Enhance Pest and Disease Control: Nitrogen boosts plant vigor but may attract pests. Monitor crops closely, use integrated pest management (e.g., fungicides/insecticides), and address issues promptly.

2. Optimize Irrigation: Maintain soil moisture after application to support nitrogen uptake and root development. Balanced irrigation improves nutrient absorption efficiency.

3. Balanced Fertilization: Supplement nitrogen with phosphorus, potassium, and micronutrients as needed. Adjust fertilization plans based on crop stages and weather to ensure steady nutrient supply.

4. Regular Testing: Periodically test soil and crops to track nutrient levels and health. Use data to refine strategies, ensuring sustainable crop productivity.

The optimal timing for topdressing nitrogen coincides with critical growth stages (jointing, heading, flowering, fruit expansion). Targeted application during these periods maximizes soil nitrogen availability. Employ uniform broadcasting, moderate dosing, deep placement, and irrigation-based techniques. Coupled with pest control, balanced fertilization, and regular monitoring, these practices enhance fertilizer efficiency, crop yields, and agricultural sustainability.