Coated Fertilizer Granules That Sink and Anchor in Flooded Fields
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Solution Overview
Problem
Existing coated fertilizers float and drift due to water current and wind, leading to uneven distribution of nutrients in flooded fields.
Innovation Solution
Coated granules with a core containing a water-soluble fertilizer material, a controlled release layer, and a surface treatment layer impregnated with a surfactant and solvent, along with a gelling agent to anchor the granules to the soil, preventing relocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If coated fertilizers use hydrophobic polymers and waxes for controlled release, then nutrient release control is improved, but the granules become buoyant and float in flooded conditions
Solution Approach 1:
The patent changes the surface properties of the fertilizer granules by applying a surfactant coating that modifies the contact angle between water and the granule surface. This parameter change transforms the hydrophobic surface into a hydrophilic one, allowing water to wet the surface and enabling the granules to sink while maintaining the internal controlled release mechanism through the urethane and wax layers.
Solution Approach 2:
The patent creates a composite structure with multiple layers: an inner controlled release layer containing urethane and wax for nutrient release control, and an outer surfactant coating layer for water affinity. This composite material approach combines the benefits of hydrophobic controlled release with hydrophilic surface properties to prevent floating.
2Adaptability or versatility
If coated fertilizers are applied in flooded fields, then crop nutrition in waterlogged soils is improved, but water current and wind transport the floating granules to areas low in plant population
Solution Approach 1:
The surfactant coating changes the surface energy and wettability parameters of the granules, enabling them to sink immediately upon contact with water. This parameter modification ensures that the granules remain stationary in flooded fields rather than floating and being redistributed by water currents or wind, thereby maintaining uniform distribution across the treatment area.
3Duration of action of stationary object
If the outer barrier layers are made hydrophobic for controlled release, then nutrient release is controlled, but the granules cannot sink and stick to the soil surface
Solution Approach 1:
The patent segments the granule structure into distinct functional layers: an inner controlled release layer with hydrophobic urethane and wax for nutrient release control, and an outer hydrophilic surfactant layer for sinking and soil adhesion. This segmentation allows each layer to perform its specific function without interfering with the other, resolving the contradiction between controlled release and sinking capability.
Solution Approach 2:
The surfactant layer acts as an intermediary between the hydrophobic controlled release layers and the aqueous environment. It mediates the interaction by providing water affinity and surface activity, enabling the granules to sink and adhere to soil surfaces while the internal hydrophobic layers continue to control nutrient release.
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 granules sink and adhere to the soil, ensuring uniform nutrient distribution and controlled release, reducing the risk of relocation and enhancing plant nutrition.
Implementation Method 1
a coating including a gelling agent... the gelling agent that serves to anchor the coated granules to the surface of the soil
Implementation Method 2
a coating including a urethane layer impregnated with a super absorbent polymer... a gelling agent that serves to anchor
Implementation Method 3
Some embodiments of the granule include an exterior wetting agent, such as a surfactant, that facilitates sinking
Implementation Method 4
an exterior wetting agent, such as a surfactant, that facilitates sinking
Implementation Method 5
a controlled release layer... a coating including a urethane layer impregnated with a super absorbent polymer
Implementation Method 6
a core that includes a water-soluble fertilizer material... controlled release layer disposed between the core and the coating
Data Source
AI summary
Coated granules and methods of making the coated granules that prevent the coated granules from floating and/or drifting due to water current and wind are disclosed. The coated granules may include a core having a water-soluble compound, such as a fertilizer; a controlled release layer; a surface treatment including a surfactant to reduce water tension; and an optional coating disposed between the controlled release layer and the surface treatment layer that includes a gelling agent, such as a super absorbent polymer, that may help to anchor the coated granules to the surface of the soil and reduces the chance of relocation due to rolling.