Achieving Standardization in Soil Testing Methods


Soil is a diverse medium and of utmost importance to our existence. Apart from being the base that supports all living and nonliving creatures, it is also the primary medium of growth for plants. Without it, we would probably all starve to death.

So when we speak of soil testing, note that it is a significant process in the survival of the ecosystem.

Soil consists of chemical, physical, and biological components that have to be maintained at optimum levels.

What is Soil Testing?

Simply put, this is the process of analyzing different elements in the soil to ensure that the soil is in the best state to support plant growth. It also involves the analysis of essential components as well as the presence of contaminants in the soil.

Why is Soil Testing Important?

The chemical and biological components of soil greatly influence its productivity. Soil testing reveals the composition of soil to guide farmers on what elements to supplement.

The soil of poor quality may lack adequate nutrients and minerals. It may also have metal contaminants or it may be too acidic or alkaline. This may derail the absorption of nutrients and hence diminish the productivity of the plants. If such factors are not addressed, the farmer risks having a poor harvest and incurring losses.

Soil testing gives farmers a full and clear picture of the state of their soil. They can know what and how much to expect from the soil and they will also have insights on how to improve the conditions of the soil.

The Soil Sampling Process

The sampling process involves the selection of a representative sample for testing. Usually, the sample is collected in a zigzag pattern. The soil should be collected without being chemically or biologically altered.

Methods of Soil Testing

Soil testing can be classified as either mechanical or chemical. Mechanical testing involves determining the size of the soil particles and the weight. Chemical testing involves testing for the elements present in the soil. This includes nutrients, minerals, pH level, heavy metals, and other contaminants.

Heavy metals that are likely to accumulate in soil include lead, arsenic, mercury, and petrolatum products. These metals find their way from the soil to the growing plants. When consumed, these accumulated metals cause toxicity in humans.

Soil testing is not just affected by the laboratory procedure used, it is also affected by the sample size, soil extraction ratios, container size and shape, as well as the shaking time and speed.

Soil Testing Laboratories

Analytical testing of soil samples should be carried out after every 3-5 years. Soil testing laboratories are tasked with the responsibility of conducting soil sampling, testing and analysis, and securely delivering the results.

Processes Involved in Soil Testing Include:

  • Soil sampling: Soil testing usually begins with soil sampling as has been explained above. The soil sample needs to be obtained from soil that is 0 to 30 cm in depth.
  • Preparing samples for analysis: Once collected, the soil sample needs to be dried and pulverized before testing.

Common Tests Performed on Soil:

  • Dry matter test: This tests for the weight of the dry soil.
  • pH test: The pH of the soil is the measure of the acidic or alkaline levels. The pH can be tested using a pH meter.
  • Nutrient test: This tests for the nutrient levels in the soil.
  • Soil organic matter: Organic matter in soil is tested by determining the “loss on ignition.” In other words, the amount of weight that is lost when the soil is heated to a temperature of 400°C.

Why is Standardization Important in Soil Testing Methods?

Standardization is important for various reasons. If different laboratories use non-standard testing techniques, they may produce different results. Consequently, it will be difficult for farmers to determine what to supplement in the soil and by what quantity. This could easily lead to the under or over-supplementation of nutrients, minerals, and other elements. In turn, this will affect the quality of the soil and limit productivity.

How can Standardization be Achieved?

Modern soil testing laboratories are turning to advanced techniques to ensure accuracy and efficiency in their soil testing methods. High-resolution mass spectrometry is being used as a new method in soil analysis. Liquid chromatography and mass spectrometry are also commonly used.

Drawbacks of Conventional Data Management Methods

When laboratory workflows are not automated, laboratory personnel have to spend a lot of time organizing and analyzing the data. Traditionally, soil testing laboratories have used manual methods for data management such as spreadsheets and paper-based methods.

Apart from being cumbersome, outdated techniques have a negative impact on laboratory efficiency. This is because they limit productivity and efficiency and at the same time slow down the decision-making process.

Such methods are not only time-consuming but also create bottlenecks that limit throughput and performance.

How Can a LIMS Help?

A modern Laboratory Information Management System (LIMS) can help a soil testing laboratory to scale up their operations and hence increase their output. An agriculture and farming LIMS can help a soil testing laboratory overcome conventional data management challenges and help them produce consistent results.

An Agriculture LIMS can help to track samples from their origin (traceability) and facilitate seamless exchange of data with laboratory instruments. It eliminates tedious paperwork and minimizes human errors in the soil testing process. Furthermore, a LIMS streamlines QA/QC processes, manages QC data, and enforces standard operating procedures (SOPs) through strong process controls.

Role of an Agriculture & Farming LIMS in Secure Delivery of Test Reports

With Agriculture & Farming LIMS, farmers can register their sample test requests and track the status of their requests. They can also download the test reports once their samples have been tested. This improves customer satisfaction and reduces turnaround time.

It can also provide a web-based portal for farmers to track their test requests in real-time and download test reports as soon as they are released using any internet-ready device. With this, farmers will be able to make informed decisions quickly and take necessary actions as soon as possible.


Soil testing helps farmers to know the state of their soil and how to optimize it for plant growth.

An agriculture LIMS can automate and streamline soil testing workflows, eliminate errors and inefficiencies.

The agricultural industry as a whole is experiencing a radical shift towards digitization. This offers opportunities for integrating farming technologies that optimize production, efficiency, and profitability.