Measure Soil Moisture Content using the Gravimetric Method

What is soil moisture?

Composed of minerals, organic matter, microorganisms and more, soil has a variety of functions; it provides an environment for plants to grow, a nest for animals, storage of water, a recycling system for nutrients and influences the Earth’s environment.1 Ultimately, soil is a crucial component of our ecosystem.

Using the gravimetric method to measure soil moisture

Soil development is largely dependent on water. Water is absorbed into the soil where it then acts as a solvent moving nutrients throughout the soil. Nutrients are needed for the plants to grow. The water content of soil greatly supports soil’s main functions, without water: nutrients would not be recycled and transferred to the root of plants, allowing them to grow; and microorganisms would be unable to live in the dry soil conditions; amongst much more. Most soil moisture comes from surface water on the soil achieved through irrigation or weather conditions such as rainfall.

Why should you measure soil moisture content?

Measuring soil moisture is essential in agriculture. Extreme amounts of or too little water content of soil negatively affects multiple soil functions. Such conditions, creates an unfavourable environment, lowering the number of microorganisms present in the soil. An excessive water content of soil impacts the transfer of nutrients through the soil due to negative impacts on the soil’s physical characteristics. On the other hand, limited soil water content diminishes soil quality. Soil quality affects the development and condition of crops growing within the soil. A good soil quality will ensure crops develop to the highest of standards, without the requirement for excessive use of fertilisers. Poor soil quality will largely impact farmers production.2

Measure soil moisture to determine soil moisture content. This can be done using an instrument used to measure soil moisture.

Soil water content measurement will provide a guide to when fields/crops are needing more water, eliminating wasteful use of water, and ensuring more efficient irrigation.As a result of accurate soil moisture content measurement, responsible water use can be fulfilled, improving soil health and quality.

In summary, it is important to determine soil moisture content because:

  • Soil water carries nutrients throughout the soil, supporting plant growth
  • The water content of soil can determine the time for harvest of a crop
  • Soil development and processes depend on water
  • Microorganisms need water
  • Soil water helps balance the minerals and organic matters in soil
  • Soil moisture content offers an indication for when irrigation is needed 4

Gravimetric Method for Soil Moisture Determination

A common technique utilised to determine soil moisture content is the gravimetric method. Also known as the drying method, the gravimetric method determines the moisture content of soil using a sample that is weighed prior to and after being dried. The moisture content can then be defined by establishing the weight difference between the wet and dry samples. Measuring soil moisture content using the gravimetric technique offers accurate and reliable results. 5

Instrument to measure soil moisture | Gravimetric method for soil moisture

At Precisa we offer soil moisture measuring instruments, with a range of moisture analysers that can be utilised for the application of soil water content measurement.

Our moisture analysers are made up of two critical components, a balance to capture the initial and end weight and a heat source to heat the sample. The heater is mounted on the balance along with a control panel and display.

Browse our range of moisture analysers today: Series 365 EM; Series 330 XM.

Precisa’s Moisture Content Test of Soil

View our Application Note: Moisture Determination of Garden Soil using Precisa’s Moisture Analyser. This information is intended as a guideline for development of a moisture analysis method and parameter setting.

Get in Touch

If you have any further questions relating to moisture content analysis or soil moisture measuring instruments and would like some guidance from our team, please do not hesitate to get in touch. Additionally, if you would like to stay in the loop regarding the latest news from Precisa, please take a moment to sign-up to our infrequent newsletter bellow, or follow us on social media – Twitter, LinkedIn.


  2. What is Poor Soil Quality And How Can It Impact Your Crops? (