1、Optimizing nitrogen fertilizer application for achieving high yield
Recommended N fertilizer rate was 250–450 kg ha −1, which can increase apple yield while minimizing reactive nitrogen losses.
2、Effects of Water and Nitrogen Regulation on Apple Tree Growth
Apple yield was found to have a parabolic relationship with nitrogen application rate, with 230–260 kg·ha −1 being the theoretically optimal range for nitrogen application.
3、fertilizing_apple_trees
Rates of 0.5-0.75 ounce of ammonium nitrate per tree in each of 10 weekly applications have been used to provide 0.1-0.15 pound of actual nitrogen per tree over the season.
4、Effects of nitrogen fertilizer types on apple tree growth, fruit
In this study, three different types of nitrogen fertilizers, urea (U), urea ammonium nitrate liquid fertilizer (UAN), and urea + calcium ammonium nitrate (UCAN), were used in a two|year drip fertigation trial with densely planted dwarf apple trees as the research object to investigate the effects of different nitrogen fertilizer types on the ...
When and How Much Nitrogen Should Be Applied in Apple Orchards?
In addition to soil application of N fertilizers, foliar N application can help to satisfy the tree nitrogen demand early in the season or to improve tree reserve nitrogen status after harvest in the fall.
Nitrogen Application Timing and Levels Affect the Fate and Budget of
This study aimed to determine the effects of the nitrogen (N) application period and level on the fate of fertilizer N and the contribution of N absorption and translocation to apple organ N.
Effects of different rates of nitrogen fertilizer on apple yield, fruit
Collectively, N fertilization slightly affected apple yield and fruit quality but significantly altered soil moisture and NO 3− -N within the 6-m soil profile. An N application rate of 412 kg ha 1 was recommended to support apple production and maintain balanced SWS 6 m and RSN 6 m for rainfed apple orchards on China's Loess Plateau.
Nitrogen Application Timing and Levels Affect the Fate and Budget of
Overall, the 15N utilization rate of arborized trees (17.33–22.38%) was higher than that of dwarf trees (12.89–16.91%). A total of 12.89–22.38% of fertilizer 15N was absorbed by trees,...
Precision Nitrogen Fertilizer and Irrigation Management for Apple
In this study, we established three levels of nitrogen application and irrigation in nine treatments in an apple orchard based on a completely randomized block design. Then, we analyzed different apple indicator responses to nitrogen and irrigation and their related interactions.
Effects of Water and Nitrogen Regulation on Apple Tree Growth, Yield
Apple yield was found to have a parabolic relationship with nitrogen application rate, with 230–260 kg·ha −1 being the theoretically optimal range for nitrogen application.
The application of nitrogen fertilizer to apple trees requires careful consideration, as nitrogen is one of the most critical nutrients for plant growth. The nitrogen needs of apple trees vary depending on factors such as cultivar, growth stage, soil type, and climatic conditions. Below is a detailed discussion on how much nitrogen fertilizer to apply during different growth stages of apple trees, along with guidelines for proper application.
1. Seedling Stage (From Planting to the Following Spring)
During the seedling stage, the root system of apple trees is not fully developed, and their ability to absorb nutrients is limited. nitrogen application during this phase should be approached with caution.
Application Recommendations:
- Initial Fertilization: Within the first 6 months after planting, apply a small amount of nitrogen, typically accounting for 5%-10% of the total annual fertilizer. This promotes root development and early growth.
- Topdressing: When seedlings reach 30 cm in height, apply 15%-20% of the total annual nitrogen as topdressing fertilizer. This supports stronger root establishment and rapid growth.
2. Growth Stage (Years 3–5)
As apple trees enter their growth stage, their nitrogen demand increases, particularly during fruit enlargement and flower bud differentiation.
Application Recommendations:
- Base Fertilizer: Apply 20%-25% of the total annual nitrogen in the fall as base fertilizer. This reserves nutrients for the next year’s flowering and fruiting.
- Topdressing:
- First Topdressing: Apply 20%-25% of the total nitrogen in early spring, before budbreak.
- Second Topdressing: Apply 10%-15% during flower bud differentiation.
- Third Topdressing: Apply 5%-10% during fruit enlargement.
3. Fruit Enlargement Stage (Year 6 and Beyond)
As apple trees mature, their nitrogen requirements further increase, especially during fruit enlargement.
Application Recommendations:
- Base Fertilizer: Apply 25%-30% of the total annual nitrogen in the fall as base fertilizer to prepare for the next season’s growth.
- Topdressing:
- First Topdressing: Apply 20%-25% in early spring.
- Second Topdressing: Apply 10%-15% during flower bud differentiation.
- Third Topdressing: Apply 5%-10% during fruit enlargement.
Key Considerations
- Soil Testing: Conduct soil tests before fertilization to determine nitrogen levels and other nutrient deficiencies, ensuring precise fertilization plans.
- Avoid Overapplication: Excessive nitrogen can lead to nutrient lockout or leaching, reducing fertilizer efficiency. Adjust applications based on soil tests and tree needs.
- Balance with Other Nutrients: Apple trees require phosphorus, potassium, and other micronutrients. Maintain balance to ensure healthy growth and yield.
- Combine Organic and Inorganic Fertilizers: Use organic fertilizers (e.g., animal manure, green manure) alongside chemical fertilizers to improve nutrient uptake and soil health.
nitrogen application for apple trees should align with their growth stages and specific needs. With scientific management and balanced fertilization, apple trees can achieve optimal health, robust growth, and high-quality yields.
