How to take Soil Samples for Testing? A Complete Guide

Soil samples for testing involve various steps but do not worry as we have got it all covered here. Knowing your soil with soil tests is a quintessential step in shaping the soil. Soil testing helps to make decisions about its needs and contents.

Soil tests also reveal the pH and nutrient status in your soil. Collecting samples from the yard for tests in the right way matters, to get a better result. Submitting better soil samples will give accurate results with better reliability. In this article, we will walk you through the steps in and around taking Soil Samples.

What are the Tools to Collect Soil Samples? 

The Tools that are needed to collect soil samples are: 

• Map– Map or mark the landscape on paper. Mark the sampled area on the map to keep a record of the place. 
• Trowel– Use a shovel, spade, or trowel made of steel to dig out the sample from the soil. 
• Soil Probe– A soil probe is an ideal tool to take soil samples. This T-shaped instrument digs deep into the soil with the required adjustments.
• Plastic Bucket– Plastic Bucket is used to mix the soil samples taken from various areas in the yard. It can also be used to collect samples.
• Plastic bag– Plastic bag is used to collect soil samples. Thin plastic bags are used to avoid contamination and to provide breathable bags for the samples.
• Waterproof marker– The Markers are used to write for the label in sample bags. This will help to identify the place from where the sample was taken.  

Where to take Soil Samples for Testing?

The soil samples for Testing should be taken from the whole area of the farm or lawn which you want to test. 

The first step in Collecting the Sample for testing is to draw a diagram of the property where you collect the samples. Plot the area in a zig-zag pattern for future reference. 

Take a look at the marked spots in the soil if they contain fertilizers, wet spots, manure, or burned wood. Samples from these places should not be taken as they may provide different results than soil in other spots. Areas in the yard where different crops are grown or limed soil should be avoided. They can be sampled separately if needed.

After excluding the problems, take the core samples from the markings. The sample will only use a small portion of the soil but it should represent the whole area. The Core samples should be at least 10 for yards and 5 for flower beds. Mix the core samples to give a better presentation of the soil in the yard.

Why should I perform Soil Testing?

Soil Testing should be performed to know about the soil condition. Soil tests will reveal lots of information about soil such as its type, nature, pH, texture, and nutrient content in the soil. The soil type will be helpful to choose the right plant for the soil. The soil pH will help to know whether the soil is acidic or alkaline with which soil amendments can be added. The nutrient content will help to adjust the soil nutrients and maintain the soil health. The Test also reveals the minerals such as zinc, iron, and manganese in the soil along with their percentage.

How much Soil is needed for a Soil Test?

The soil needed for a soil test is 2 cups. Collecting the soil samples from various zones of the yard and mixing them and giving one cup is enough for basic tests. For advanced testing, 2 cups of soil should be presented as the soil sample for testing. In laboratory testing, they may ask for more sample soil depending on your choice of soil tests.

How deep should Soil Samples be taken?

The Depth of the soil sample depends on the types of soil as well the crops in the soil. Remove the debris in the soil before inserting the spade or trowel. This will avoid lumps or unnecessary waste with the soil sample. Now, you can take multiple samples of soil in the desired pattern with the below-given measurements,

The Topsoil sample should be collected at 4 inches depth whereas subsoil samples at the depth of 8-12 inches.

For,

• Turf, Lawn area- 4 inches.
• Garden, shrubs, and landscape- 6 inches.
• Trees and roots plants- 10 inches.

What are the Do’s and Don’ts of Collecting Soil Samples?

Some of the do’s and don’ts in collecting the soil samples are,

• Do Collect the Soil Samples three to six years before planting time. In this way, you can get the result before the lime time for the soil. You can also avoid fertilizer or lime in the soil sample which will change the soil test result.
• Do Collect the samples in a plastic bag or special bags provided by the testing center to get accurate results. Collecting in any other containers may change the soil texture and condition.
• Do collect soil samples once a year to check on the conditions of the soil. Try to take soil samples from the same place and same time every year.
• Don’t collect soil from places that are full of waste such as burned wood ash, and manure. Giving such a sample won’t give the right result about the soil. Any waste in the soil can change the soil’s pH.
• Don’t Collect Soil Samples from Wet soil. Wet soil is difficult to mix with the core samples. Wet soil won’t give a good result.

How many Soil Samples should I take?

The Soil Samples to take for the core sample depends on various factors like soil type, crop, area, and color. But the recommended sub-sample count is 10 to 15 per acre of the land. The more sub-sample is mixed in the soil, the more accurate the results. Let us take a yard that has four zones of different sizes. Collecting a minimum of 5 sub-sample per zone is best. In this way, you will get a total of a minimum of 20 sub-samples for the core sample. Soil Samples should cover the whole surrounding of the soil to give the exact profile of the soil in soil tests.

How to send Soil Samples for Testing?

Soil Samples for testing should be sent in a proper container or plastic bag. After collecting the samples from the pattern places, mix them well. With the help of a bucket and shovel, mix the samples well for packing. Pack the well-mixed soil in a plastic bag which avoids air and water into the soil. It can also be stored in an airtight container or as mentioned by the soil testing labs. Proper packing is necessary to avoid any risk of destroying the sample. Make sure the soil samples are dry and free from debris before packing them to send for testing.

What Information should be added to Soil Samples?

The most basic information that should be added to soil samples is soil name, tillage depth, and characteristics. With these things, the surveyor can give the result about the soil. Other information to be given for lawns or gardens are, Crops selected to be grown, fertilizer, or any addition used in the soil which may change the soil tests. For cultivated crops, soil characteristics, present crop and age, past crop, future crop, and cover crops used in the soil. This information should be labeled or packed with the soil samples which are sent to the soil survey. 

How long do Soil Samples last?

Soil samples can last for up to a week with proper storage. The storage of soil determines the life of soil samples. Generally, soil samples can be stored at 4 degrees Celsius for up to 1 week without any change in the soil naturally. To store for more weeks, store in a cold area with a lesser degree of humidity. For example, if you want to store soil samples for longer than 4 weeks, then store them at minus 20 degrees Celsius. Air drying or freeze drying is the best way to store samples without changing the variables in the soil.

How much does it Cost to get a Soil Sample Tested?

Getting a soil sample tested, costs around a minimum of $300 to $500. For one sample with the basic pH, nutrients, and organic matter it cost around $90. The standard test includes the above tests with nitrogen data and costs $85 per sample. Specific pricing includes pH -$35, Soil texture- $40, Soil organic matter- $60, and Total mineral analysis $140. Advanced soil testing may cost more than $ 500. The test rates also change depending on the size of the soil sampling area. The prices may vary according to the lab or test center and the location. 

How many Days will it take for Soil Testing?

Soil testing takes more than ten days to get the final report. The process of soil testing starts after getting the soil samples and giving them to the laboratory. The testing days can change on the type of test it is given, standard testing takes 5 days to full soil testing may take longer time. Soil testing may vary depending on the center or testing lab.

Are Soil Tests worth it?

Yes, soil tests are worth it. Soil testing will reveal all information about the soil. Soil testing will increase crop production by helping to select the right crop for the right soil. Soil tests help to improve the nutritional balance of the soil by knowing the present nutrients in the soil. It also avoids soil health problems by maintaining the right nutrient amount in the soil. Soil tests also reveal the existing contaminations and fertilizers in the soil. This helps to leach the excess fertilizers and contaminants in the soil.

Can I Test Soil on my own?

Yes, Soil can be tested on your own. Soil testing can be done on your own or in laboratories. Testing soil on your own takes time, research, and tools whereas laboratory tests cost more money. Testing soil by buying a soil test kit online is the first step after collecting samples. Soil samples can be collected in the above-mentioned way. You can find the soil texture, health, and pH on your soil testing.

To find the texture of the soil, take a pea-sized ball of soil in hand. If the soil breaks – sandy, sticky- clay and stones, and debris- silty soil. To test pH, buy a kit that gives certain instructions to test the soil. To know the soil health, search for earthworms in the soil. Earthworms are seen as healthy soil because they thrive on organic matter.

How Accurate is Soil Testing?

Soil accuracy can’t be determined. Soil accuracy depends on the soil samples collected for testing. Mostly the soil tests are not accurate. The reasons are different sample collecting methods, soil variations, and weather changes. Soil testing accuracy can change due to sample collecting patterns such as the zig-zag method, T method, and many others. The sample from one place may have different soil and other places have different soil. The climatic conditions also change the accuracy. If the testing is done in one season, the next season the soil test result is not the same.

What are the 5 things that a Soil Sample Test Report will tell you?  

The 5 things the soil test report will tell you are Organic matter, nutrients, pH, NPK content, and Micronutrients. 

Organic matters are the organic component in the soil. It includes the living matter, decomposing, decomposed, and stable organic matter in the soil.

NPK contents include the Nitrogen, Potassium, and phosphorus contents in the soil. These are the main and big three nutrients in the soil which are a must for soil to be healthy. Nitrogen helps in the protein intake of the plant. Potassium helps the plant’s strength and resistance to disease. Phosphorus helps in the storage of energy in the plant. The Nitrogen content is mostly not presented in a soil test without asking specifically for it.

The other nutrients include magnesium, calcium, sodium, sulfur, zinc, iron, copper, and Boron. These nutrients are present in the soil to keep the soil healthy and fertile. 

Soil pH will provide the result if the soil is acidic or alkaline. Soil pH of 7 is neutral, less than 7 is acidic and greater is alkaline. Soil with 6 to 7 soil pH is ideal to grow healthy plants.

Conclusion

 Providing a proper soil sample will get the right soil test result. Soil Test results will provide improvement suggestions for the soil. They also provide remedies for problems and enhancement of soil fertility. With these recommendations, you can move forward in working with the soil.

FAQ’s

1. When should a Soil Sample be taken?

Early fall is the best time to take soil samples.

2. How many types of Soil Sampling methods are there?

There are mainly four types of soil sampling methods available.