PHA-Coated Nitrogen Fertilizer for Controlled Soil Release

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Solution Overview

Problem

Current nitrogen fertilizers, particularly urea, are highly water-soluble, leading to rapid dispersion and concentration fluctuations in the soil, necessitating frequent application and causing environmental pollution. Existing slow release fertilizers use non-biodegradable and non-biocompatible synthetic polymers, contributing to environmental accumulation.

Innovation Solution

Coating nitrogen fertilizer particles with a biodegradable and biocompatible polyhydroxyalkanoate (PHA) layer, optionally with an adhesive and sealing layer, to create a semi-permeable barrier for controlled nutrient release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If nitrogen fertilizer particles are coated with synthetic polymers (polypropylene, polyethylene, polyurethanes) to achieve slow release, then the dissolution of the fertilizer is regulated, but the polymers are not biodegradable and accumulate in the soil, causing environmental harm

Engineering Contradiction:

Improveduration of nitrogen releaseVSAvoidenvironmental accumulation of non-biodegradable polymers

Core Design Contradiction:

Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter from synthetic non-biodegradable polymers to biodegradable polyhydroxyalkanoates (PHA), which are naturally occurring polymers that decompose under soil conditions. This parameter change maintains the slow release function while eliminating the harmful accumulation effect, as PHA coatings break down into harmless substances over time.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure where nitrogen fertilizer particles are coated with biodegradable PHA polymer layers. This composite approach combines the slow release property of polymer coatings with the biodegradability of PHA, creating a fertilizer product that functions effectively while being environmentally friendly and non-accumulative in the soil.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If nitrogen fertilizer is applied in high concentrations to meet crop needs, then the nutritional requirements are satisfied, but the concentration exceeds the ability of vegetation and soil microflora to metabolize it, causing environmental overload

Engineering Contradiction:

Improvenitrogen concentration in soilVSAvoidenvironmental overload of nitrogen

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamic release control by using PHA coating that degrades at different rates depending on soil conditions. This dynamic degradation process allows the nitrogen release to adapt to crop needs over time, preventing both deficiency and excessive concentrations that would cause environmental overload.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The PHA coating provides continuous slow release of nitrogen throughout the growing season, maintaining a steady supply that matches the continuous nutritional needs of the crop. This continuous action prevents the peaks and troughs in nitrogen concentration that lead to metabolic overload and environmental pollution.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If nitrogen fertilizer is applied frequently to optimize crop life cycle, then the nutritional needs are met, but numerous adverse environmental effects occur including nitrate release into aquifers and nitrogen oxides in the atmosphere

Engineering Contradiction:

Improvecrop nutritional optimizationVSAvoidnitrate and nitrogen oxide emissions

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The PHA coating is applied to the nitrogen fertilizer particles before planting, creating a controlled release mechanism that prevents rapid dissolution and subsequent leaching. This preliminary coating action ensures nitrogen is released gradually throughout the season, eliminating the need for frequent applications that would cause nitrate and nitrogen oxide emissions.

Inventive Principle:

Principle #10Preliminary action

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 PHA coating provides a slow and controlled release of nitrogen, aligning with crop nutritional needs while being environmentally friendly by avoiding harmful accumulation.

Implementation Method 1

the fertilizer particles are coated with a semi-permeable layer that is able to regulate the dissolution of the fertilizer in the soil

Methodology Applied

Scientific EffectSemipermeable membrane: Semipermeable Membrane

Implementation Method 2

coating the particles of a nitrogen fertilizer with at least one polyhydroxyalkanoate (PHA) so as to obtain a layer having a predefined thickness

Methodology Applied

Scientific EffectBiological decomposition: Decomposition (biological)

Data Source

PatentUS12391628B2Slow release fertilizing composition, and process for producing the same

Publication Date: 2025.08.19 BIO ON SPA

AI summary

A slow release fertilizer composition includes particles of a nitrogen fertilizer coated with at least one layer having at least one polyhydroxyalkanoate (PHA), the at least one layer having an average thickness between 1 μm and 200 μm. The relative production process is also described. The slow release fertilizer composition provides for the use of biodegradable and biocompatible materials that allow a slow release of the fertilizer in the culture medium, according to the current regulations, without causing the accumulation of products which are harmful for the environment.