Comprehensive Guide to Autumn Fertilization Management for Fruit Trees：Potassium Humate & Seaweed Extract Organic Fertilizers

Autumn Fertilization Management for Fruit Trees

Autumn is the final growing season of the year for fruit trees. It is the time when mid to late-maturing varieties ripen and also a crucial period for deep differentiation of flower buds and the storage of organic nutrients. Therefore, effective fertilization management during this period is vital for several reasons:

① Immediate Benefits:

Pest and Disease Control: Proper fertilization can help in effectively controlling the onset and spread of pests and diseases.

Enhanced Yield and Quality: Good nutrient management, including the use of Organic Seaweed Fertilizer,  can improve both the quantity and quality of the fruits harvested in the current year, ensuring increased income for farmers.

②Long-Term Benefits:

Post-Harvest Recovery: Effective fertilization sets the stage for the tree's recovery after fruit harvesting.

Winter Hardiness: Adequate nutrient storage, particularly through Seaweed Extract for Plants,  enhances the tree's ability to withstand cold winter conditions.

High-Quality Yield for the Following Year: Proper fertilization now can lay the foundation for high-quality and high-yield fruits in the next growing season.

Overcoming Alternate Bearing: Effective nutrient management can help overcome the phenomenon of alternate bearing, where the tree produces a large crop one year and a smaller one the next.

By paying attention to fertilization management in the autumn, not only can immediate benefits be reaped, but a strong foundation can also be laid for the tree's future growth and productivity.

1. The Four Stages of Nutrient Needs in Fruit Tree Growth

Spring Bud and Flowering Stage: In the early spring, fruit trees primarily rely on their stored nutrients for bud sprouting and flowering. During this stage, the trees absorb minimal nutrients from the soil.

Nutrient Exchange Stage: As the new shoots begin to grow, the stored nutrients in the tree are depleted. This triggers the tree to start actively absorbing nutrients from the soil.

Root Nutrient Absorption Stage: This phase starts from the setting of the fruit and continues until the fruit is harvested. During this period, the root system of the fruit tree is actively involved in nutrient absorption.

Nutrient Storage Stage: At this final stage, the fruit tree ceases to grow. All the nutrients that have been absorbed are stored within the tree for future use. Even the nutrients from fallen leaves are reabsorbed and stored within the tree.

2. Two Peak Periods of Nutrient Absorption in Fruit Tree Growth

Fruit trees experience two peak periods of nutrient absorption during their growth cycle:

First Peak Period: This occurs from spring flowering, leaf growth, to fruit setting. During this phase, the tree primarily absorbs nitrogen.

Second Peak Period: This takes place during the fruit enlargement stage. During this phase, the tree mainly absorbs potassium, making potassium humate organic fertilizer particularly useful.

Nutrient Specifics:

Nitrogen: The absorption of nitrogen is higher during the first peak period compared to the second.

Potassium: The tree absorbs more potassium during the second peak period.

Phosphorus: The absorption of phosphorus remains relatively stable throughout the year.

3. Fertilization Timing

For mid to late-maturing varieties, fertilization is generally carried out around the time of fruit harvesting. The principle is to fertilize earlier rather than later. Here's why:

Temperature and Rainfall: During this period, the temperature is high and there is ample rainfall, providing sufficient time for the base fertilizer to decompose.

Leaf Functionality: At this time, the leaves have not yet started to decline in their photosynthetic capabilities. This allows for a strong flow of nutrients back to the roots.

Root System Growth Peak: This period coincides with another growth peak in the fruit tree's root system, which can significantly improve the tree's nutrient storage levels.

Understanding the optimal timing for fertilization is crucial for maximizing nutrient absorption and enhancing the overall health and yield of the fruit tree.

4. Fertilization Methods

There are several primary methods for applying fertilizer to fruit trees, each with its own advantages and considerations:

①Ring Trench Method: A circular trench is dug around the outer edge of the tree canopy. The trench is usually 30-50 cm deep. This method is often used for young trees. The position of the ring trench should be adjusted outward each year as the tree canopy expands.

②Radial Trench Method: Starting from the tree trunk as the center, trenches are dug in the direction of the horizontal root system. Usually, 4-6 trenches are dug, each with a depth and width similar to the ring trench. The trenches are located 1-1.5 meters away from the trunk, and their depth increases gradually from the inside out. This method is less damaging to the roots and is suitable for mature fruit trees.

③Whole Orchard Broadcasting: This method is suitable for mature fruit trees and densely planted orchards. The fertilizer is evenly spread throughout the orchard and then incorporated into the soil by plowing. The plowing depth should be around 20-25 cm. While this method allows for widespread root absorption, the shallow application depth can lead to root surfacing and shallow rooting. It is advisable to alternate this method every other year.

Understanding the appropriate fertilization method is crucial for effective nutrient management, which in turn can significantly impact the health and yield of the fruit trees.

④Foliar Fertilization in Fruit Trees
Foliar fertilization involves applying nutrient elements directly to the surface of fruit tree leaves. These nutrients are absorbed by the leaves and directly participate in photosynthesis, providing dry matter to support plant growth and development.

Mechanisms of Absorption:

Cuticle and Wax Layer: One pathway for nutrient absorption is through the cuticle and wax layer of the epidermal cells on the leaf surface.

Stomata: Another pathway is through the stomata located on the underside of the leaves.

Advantages

Rapid Absorption: This method bypasses the need for nutrients to be absorbed by the root system and then transported to the leaves, resulting in quicker nutrient uptake.

High Fertilizer Utilization Rate: The nutrients are directly absorbed where they are needed, making this method highly efficient.

Promotes Plant Growth: The direct supply of nutrients can significantly boost plant growth and development.

Foliar fertilization is also a form of top-dressing, providing an additional nutrient supply to complement root-based fertilization methods.

Understanding the benefits and mechanisms of foliar fertilization can offer an effective way to enhance nutrient management in fruit tree agriculture.

5. Fertilization Management

Starting from early September, late-maturing fruit trees experience a significant increase in fruit-bearing branches. Additionally, the autumn season often brings more rainfall, leading to poor ventilation in the orchard and a higher risk of pests and diseases. Therefore, it's crucial to employ effective fertilization techniques to achieve the following goals:

Promote Fruit Enlargement: Proper fertilization can help fruits grow larger.

Enhance Fruit Coloring: The right nutrients can improve the coloration of the fruits.

Increase the Rate of High-Quality Fruits: Effective fertilization can lead to a higher percentage of top-grade fruits.

Strengthen Disease Resistance: Adequate nutrient supply can enhance the tree's ability to resist diseases.

Guiding Principles:

The crop regulation and care plan by HUMICO follows the principle of "Control Nitrogen, Reduce Phosphorus, Increase Potassium, and Supplement Micronutrients." This approach aims to improve the quality, resilience, and yield of fruit trees during their mid-to-late growth stages.

Understanding these principles and techniques is essential for effective fertilization management, which in turn can significantly impact the health, yield, and quality of the fruit trees.