Multi-Coating Controlled-Release Fertilizer for Crop-Stage Nutrition
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Solution Overview
Problem
Existing fertilizers fail to meet the nutritional needs of crops throughout their entire growth cycle, requiring multiple applications and high labor intensity, and are not suitable for large-scale agriculture.
Innovation Solution
A method for preparing multi-layer coating structure slow/controlled-release fertilizer, using polyurea formaldehyde as a coating layer with urea and formaldehyde at a molar ratio of 1-2.5:1, to create a spherical fertilizer granule with separate fertilizer and coating layers, allowing for timed and synchronized nutrient release based on crop growth stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple types of fertilizers are applied separately to meet crop nutritional needs throughout growth cycle, then nutrient requirements are satisfied, but labor intensity and fertilization cost increase
Solution Approach 1:
The patent combines multiple fertilizer types (urea, calcium superphosphate, potassium dihydrogen phosphate) into a single granular fertilizer product with multi-layer coating structure. Different fertilizer layers are coated around a core, allowing one application to provide N, P, and K nutrients simultaneously, eliminating the need for separate fertilizer applications and reducing labor intensity
Solution Approach 2:
The fertilizer is segmented into multiple functional layers with different coating materials and release characteristics. The multi-layer structure includes inner and outer coatings with different solubilities and release rates, allowing each layer to release nutrients at different times to match crop growth stages, thereby satisfying complete nutritional needs in a single application
2Ease of manufacture
If conventional fertilizers with fixed elements are used, then fertilizer application is simple, but fertilizer utilization rate is low
Solution Approach 1:
The fertilizer employs dynamic release characteristics through its multi-layer coating structure. The different coating materials have varying solubilities and degradation rates, allowing the fertilizer to dynamically adjust nutrient release rates according to soil conditions and crop needs. This dynamic release improves utilization rate while maintaining simple application methodology
Solution Approach 2:
The fertilizer uses composite material structure with multiple coating layers containing different materials (e.g., urea coating, phosphorus coating, potassium coating). Each layer is composed of specific materials with tailored properties, creating a composite fertilizer that enhances overall utilization rate while keeping application simple
3Reliability
If soilless cultivation with nutrient detection is used, then nutrient replenishment is timely, but investment and maintenance costs are high
Solution Approach 1:
The fertilizer is designed with pre-determined multi-layer structure where nutrient release timing is predetermined during manufacturing. The different coating layers are engineered to release nutrients at specific rates and times based on crop growth requirements, eliminating the need for real-time nutrient detection and active management systems while ensuring timely nutrient availability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The fertilizer ensures all nutrient needs are met during the crop's growth cycle with minimal applications, improving utilization rates and reducing costs, suitable for large-scale agriculture.
Implementation Method 1
The raw materials of the polyurea formaldehyde are urea and formaldehyde, the molar ratio of the urea to the formaldehyde is 1-2.5:1
Implementation Method 2
the release rates of the nutrient compounds are controlled by regulating the solubilities of the limited-soluble compounds
Data Source
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AI summary
Disclosed are a multi-coating-structure controlled-release fertilizer and a preparation method therefor, which relate to the field of fertilizers. The multi-coating-structure controlled-release fertilizer comprises fertilizer layers and coating layers which are coated layer by layer, wherein the fertilizer layers and the coating layers are arranged in a spaced manner, at least two fertilizer layers are provided, at least one coating layer is provided, and one of the fertilizer layers is used as a core of the fertilizer; the fertilizer layer contains at least one of a nitrogen fertilizer, a phosphatic fertilizer and a potassic fertilizer, and the coating layer is a polyurea formaldehyde, wherein the polyurea formaldehyde at least contains a polyurea formaldehyde having 2-5 carbon atoms. Elements such as nitrogen, phosphorus, potassium, calcium, magnesium and zinc in the fertilizer can be controlled better to release so as to meet the demands of different crops for different nutrients in different stages of growth. The controlled-release fertilizer is prepared by means of a reaction kettle, a slurry tank, a dusting groove and accessory facilities thereof, and the amount of fertilizer in each layer and the positions at which the fertilizer is coated in whole fertilizer particles can be controlled according to a design program. The whole process can be carried out intermittently, and can also be carried out continuously, and the fertilizer can be produced on a large scale.