Soil Moisture Estimation Using Capacitance and Evapotranspiration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for measuring soil moisture are either time-consuming and labor-intensive, or they have limitations such as high costs, use of radioactive materials, and inability to provide immediate feedback, making them unsuitable for continuous monitoring and accurate irrigation decisions in agriculture and civil engineering applications.

Innovation Solution

A method involving capacitance measurements of the soil surface, combined with local climatic and hydrological data, and an evapotranspiration model to estimate soil moisture profiles, which can include machine learning algorithms and direct measurements from soil moisture probes, to provide accurate and rapid soil moisture calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the oven drying method is used to measure soil water content, then measurement accuracy is improved, but time consumption and labor intensity increase

Engineering Contradiction:

Improvesoil water content measurement accuracyVSAvoidtime consumption

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical oven drying method with electromagnetic field-based capacitance sensing. The capacitance sensor measures soil moisture through electromagnetic field interaction with water molecules in the soil, eliminating the need for physical drying processes and providing immediate digital readings.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses capacitance sensors that create an electromagnetic field copy of the soil moisture state rather than physically altering the soil. The sensor measures the dielectric properties of the soil-water system, providing a non-contact measurement that replicates the moisture information without requiring the soil sample to be removed or processed.

Inventive Principle:

Principle #26Copying

2Measurement precision

If neutron probes are used for indirect soil moisture measurement, then measurement capability is improved, but device complexity and operational restrictions increase due to radioactive materials

Engineering Contradiction:

Improvesoil water content estimationVSAvoidequipment complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs inexpensive capacitance sensors that can be easily deployed and replaced without the regulatory burdens associated with radioactive materials. These sensors have no moving parts, require no special licensing, and can be disposed of or replaced economically, eliminating the complexity of certificate management and specialized operational procedures.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent extracts the measurement function from complex radioactive probe systems and implements it through simple capacitance sensing elements. By removing the radioactive source and associated safety infrastructure, the core measurement capability is retained while the harmful complexity is eliminated.

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If traditional soil moisture measurement methods are used, then measurement capability is maintained, but ability to provide immediate feedback and continuous monitoring is reduced

Engineering Contradiction:

Improvesoil water content measurementVSAvoidcontinuous monitoring capability

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent enables continuous monitoring by deploying capacitance sensors that can continuously measure soil moisture without interruption. The sensors provide real-time data streams that can be fed into irrigation control systems, allowing for dynamic adjustment of water application based on current soil moisture conditions rather than periodic sampling.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent implements feedback loops where capacitance sensor measurements are continuously fed back to control irrigation systems. The real-time soil moisture data triggers automated responses, such as activating or deactivating irrigation valves, creating a closed-loop system that reacts immediately to changing soil moisture conditions.

Inventive Principle:

Principle #23Feedback

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

This approach allows for accurate, rapid, and cost-effective estimation of soil moisture profiles, enabling better-informed irrigation decisions and continuous monitoring, thereby improving agricultural and civil engineering applications.

Implementation Method 1

obtain a capacitance measurement of a soil surface at a location

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

obtaining a capacitance measurement of a soil surface

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS12259349B2Soil moisture estimation

Publication Date: 2025.03.25 UNIVERSITY OF MELBOURNE

AI summary

A method of calculating a soil moisture profile includes obtaining a capacitance measurement of a soil surface at a location, applying a preselected calibration to the capacitance measurement to obtain a top surface moisture estimate, obtaining local climatic and hydrological data correlated with the location, the local climatic and hydrological data, which includes at least local water input data, and calculating an estimate of the soil moisture at the location by applying a preselected evapotranspiration model to the top surface moisture estimate and the local climatic and hydrological data.