1、Optimal Nitrogen Fertilizer Rates for Soybean Cultivation

Legume plants, which include soybeans, generally do not require copious nitrogen fertilizer application because they can live in symbiosis with rhizobia, leading to the reduction of atmospheric N 2 forms available for the host plant. They require only small amounts of available nitrogen at the start of the growing period.

2、Optimizing nitrogen supply promotes biomass, physiological

Abstract Avoidable or inappropriate nitrogen (N) fertilizer rates harmfully affect the yield production and ecological value. Therefore, the aims of this study were to optimize the rate and timings of N fertilizer to maximize yield components and photosynthetic parameter of soybean.

3、(PDF) Nitrogen management in Soybean: A Review

Although grain legumes (e.g., soybean) production requires low or even no N fertilization, the amount of N 2 fixed is controlled by various factors, e.g., the effectiveness of the...

Nitrogen Fertilizer for Soybean

Because research on timing of N application to soybean has not produced consistent results, the question of optimum timing remains unanswered. However, understanding more about a soybean plant's variable needs for N throughout its life cycle can provide some guidance for application timing.

Boost Yields with Smart Soybean Fertilizer Timing and Rates

Soybeans may fix their own nitrogen, but they still need balanced fertility, especially phosphorus, potassium and sulfur, to reach their full potential. Getting the timing and rates right can...

Integrated irrigation and nitrogen optimization is a resource

This study develops an integrated strategy by optimizing irrigation and nitrogen inputs to provide effective and sustainable solutions for climate change adaptation in US agriculture.

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Additionally, effective crop management strategies, encompassing optimal sowing dates, seeding rates, tillage methods, and chemical pest control, are essential for maximizing soybean productivity and ensuring sustainability (Guo et al., 2022, Szostak et al., 2020).

Timing of N Application Affects Net Primary Production of Soybean with

Overall, results of this study demonstrated that applying starter-N plus topdressing N could significantly enhance soybean photosynthetic capacity after stage R5 at planting density of 25 plants m-2.

Optimal Nitrogen Fertilizer Rates for Soybean Cultivation

The aim of this study was to determine the effect of varied nitrogen fertilizer application rates on the dry weight of the separated parts of soybean plants and the whole plant, including the number and weight of root nodules, the potential to reduce atmospheric nitrogen (N2), and the content and uptake of nitrogen.

Temporal Synchronization of Nitrogen and Sulfur Fertilization

It can be concluded that the basal and split application of N and S at the rate of 25 kg ha−1 can improve soybean productivity through increased mobilization and assimilation by plants.

Soybean, a critical crop for oil, feed, and food, relies heavily on proper nitrogen (N) fertilization during its growth cycle. Strategic N application promotes healthy development, yield, and quality. Below are recommendations for timing and methods of N fertilization in soybean:

I. Soybean Growth Stages and Nitrogen Application Timing

1. Seeding Stage: Applying N fertilizer at seeding provides essential nutrients for germination and seedling establishment, supporting early growth.

2. Tillering Stage: Nitrogen demand increases during tillering. Timely N application enhances root development, stem elongation, and stress resistance.

3. Flowering Stage: N fertilization during flowering improves flower organ formation, pollination success, and pod setting, directly impacting yield.

4. Pod-Filling Stage: Continued N application supports pod development, increases pod count per plant, and boosts grain weight, thereby improving yield and quality.

5. Maturation Stage: Excessive N at maturity may reduce protein content. Adjust N rates to balance yield and quality, avoiding over-fertilization.

II. Nitrogen Application Methods

1. Basal Application: Incorporate N into the soil pre-planting. Suitable for large-scale farming, but ensure even distribution to prevent root damage.

2. Topdressing: Apply N during growth stages based on plant needs and soil fertility. Flexible but risks excessive growth or reduced quality if over-applied.

3. Foliar Spraying: Deliver N directly to leaves via spraying. High nutrient absorption efficiency, but labor-intensive and weather-dependent.

4. Drip Fertigation: Use drip irrigation for precise root-zone fertilization. Minimizes environmental loss but requires high upfront investment.

III. Key Considerations

1. Soil Type:

   • Sandy soils: High leaching risk; use controlled-release N.
   • Clay soils: Slow N uptake; prefer ammonium-based fertilizers.

2. Climate:

   • Drought-prone areas: Avoid excess N to prevent "burning" seedlings.
   • Rainfed regions: Increase N slightly to support growth.

3. Varietal Differences:

   • High-protein soybean varieties require more N.
   • Fiber-type varieties need less N. Tailor applications accordingly.

4. Timing Precision:

   • Early applications (e.g., 10–15 days after emergence) optimize N uptake.
   • Late applications (e.g., pod-filling) still boost yield but are less efficient.

Optimal N management in soybean production depends on soil, climate, variety, and timing. Scientific fertilization maximizes yields, economic returns, and environmental sustainability.