1、Reducing the reliance on nitrogen fertilizer for wheat production

Applying little or no fertilizer but harvesting of crops leads to depletion of soil mineral reserves and deterioration of soil quality. Yields in such circumstances are clearly not sustainable and the application of NUE estimations is erroneous.

2、The fates of 15N

Appropriate fertilization practice is crucial to achieve maximum wheat grain yield with minimum nitrogen (N) loss.

3、Short

We set up a pulse-15N labelled field experiment in which N was applied at eight development stages from tillering (beginning of March) to anthesis (mid-June). Each application was 50 kg N ha-1 as 15N labelled urea except for the first application which was 25 kg N ha-1.

4、Optimizing Fertilizer Nitrogen for Winter Wheat Production in Yangtze River Region in China

From 2007 to 2009, field experiments were conducted to evaluate the effects of optimized N management on grain yield, nitrogen use efficiency (NUE) and N surplus of winter wheat in Jianghan Plain (Hubei province, China).

Yield response of wheat to nitrogen and potassium fertilization

Keeping in view the importance of N and K fertilizer application for improved wheat yield and quality, this experiment was initiated to study the response of qualitative and quantitative parameters of wheat to different N and K levels in an alkaline calcareous soil.

Yield and water use responses of winter wheat to irrigation and nitrogen application in the North China Plain

With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat (Triticum aestivum L.) in the North China Plain (NCP).

Optimizing water and nitrogen inputs for winter wheat cropping system on the Loess Plateau, China

In order to optimize water and nitrogen (N) management for winter wheat, we conducted field experiments from 2006 to 2008 at the Changwu Agro-ecological Experimental Station of the Chinese Academy of Sciences on the Loess Plateau, China.

Nitrogen losses from fertilizers applied to maize, wheat and rice in the North China Plain

Ammonia volatilization, denitrification loss and total nitrogen (N) loss (unaccounted-for N) have been investigated from N fertilizer applied to a calcareous sandy loam fluvo-aquic soil at Fengqiu in the North China Plain.

Nitrogen use efficiency in grain production and the estimated nitrogen input/output balance in China agriculture

IFA Int. Workshop on Fertilizer Best Management Practice Balance of field nitrogen nutrient input/output using GIS technology in China Development and application of nitrogen balance model of agro-ecosystem in China Surface N balances in agricultural crop production systems in China for the period 1980–2015

Influence of nitrogen fertilizer application rate on winter wheat (Triticum aestivum L.) flour quality and Chinese noodle quality

Two winter wheat cultivars, with six N rates, planted during the course of a 2-year experiment were used to determine the effect of N application rate on Chinese white noodle quality.

The timing of nitrogen fertilizer application for wheat varies by region and climatic conditions, but it is generally common practice to apply fertilizer during the middle to late stages of wheat growth. Below are detailed insights into nitrogen topdressing for wheat:

1. Wheat Growth Cycle: The growth cycle of wheat can be divided into four stages: germination, tillering, jointing, and heading. Nitrogen requirements differ across these stages. For instance, during the tillering stage, wheat demands substantial nitrogen to promote root development and stem elongation; whereas during jointing and heading, nitrogen needs decrease as these stages focus on nutrient accumulation.

2. Timing of Nitrogen Application: Typically, the optimal period for nitrogen topdressing occurs in the mid-to-late growth stages of wheat, specifically during jointing and heading. At these stages, when wheat's nitrogen demand is relatively lower, moderate increases in nitrogen application can be made. These critical growth phases benefit from additional nutrients to enhance absorption and boost yields.

3. Methods of Nitrogen Application: When applying nitrogen fertilizer, consider the following:

   • Select Appropriate Nitrogen Sources: Choose suitable nitrogen fertilizers (e.g., urea, ammonium sulfate) based on soil conditions and wheat varieties.
   • Rational Fertilization: Control dosage and frequency to prevent nitrogen leaching, soil salinization, or excessive vegetative growth that could reduce yields. Tailor applications to soil fertility and crop needs.
   • Combine with Other Nutrients: Integrate phosphate and potassium fertilizers to meet diverse nutritional demands. Phosphates enhance photosynthesis and disease resistance, while potash improves drought tolerance and lodging resistance.
   • Avoid Monoculture: Rotate crops to prevent soil nutrient imbalances and pest buildup.

4. Effects of Nitrogen Topdressing: Proper nitrogen application enhances yield and quality by promoting root development, stem strength, stress resilience, and leaf growth. It also improves photosynthetic efficiency, increasing grain fill. Moderate nitrogen use elevates protein content while reducing starch levels.

5. Precautions:

   • Avoid High-Temperature Fertilization: Apply fertilizer early morning or evening to minimize volatilization.
   • Prevent Alkaline Mixing: Do not mix nitrogen fertilizers with alkaline substances, which degrade efficacy.
   • Guard Against Overapplication: Excessive use leads to soil salinization and nutrient imbalance, harming wheat growth.

nitrogen topdressing is vital for maximizing wheat productivity and quality. By timing applications correctly, adopting proper methods, and avoiding common pitfalls, farmers can optimize fertilizer benefits, ensuring robust wheat development.