Soil Health: Test Your Soil

Your soil pH number is linked to how vigorously your plants will grow. Most gardens flourish in the range of 6.0-7.0, slightly acidic to neutral. If you are lucky enough to be within this range, you won’t have to add lime or sulfur to your soils. Many soils in Allegany County range from the mid to high 5.0’s (slightly acidic); the parent materials our soil is made from influences this number. This means soils that have not had amendments, (such as compost, leaves, lawn clippings, etc.), routinely added may require an addition of lime to meet the minimal neutral pH.

pH also affects what nutrients the plant can take up in its’ roots. When pH is high (over 7.0) iron, manganese, copper and zinc in the soil become unavailable to plants. Conversely, when pH is low (below 6.0) calcium, phosphorus, and magnesium become unavailable. The nutrient may still be in the soil, however it is bound up in the soil due to the pH and the plant cannot use it.

Have your soil tested to check if you need to add lime or sulfur to adjust the pH and see your garden respond next year!

Instructions for Taking a Soil Sample for the pH testing

(Download PDF printable version)

Take Your Time!

The best time to take samples from your garden is when you have the time to do so. No need to rush, because what really matters is a great job done, if you are in a hurry while taking samples, it can take even longer if you need to take the samples again.

How often should I take samples? Most soils should be tested every 2-3 years, and more often in sandy soils or problem areas. You can do it every year if you notice changes in your soil/plants. And try to always do it at the same time of year.

Gather the necessary tools:

You'll need a clean gardening trowel or a soil sampling tool, a clean bucket, and a sampling tube or container to collect the sample (example: a clean zip-top bag or plastic container).

Determine the sampling locations:

Divide your garden into different areas based on soil type, plant types, or any noticeable differences in growth. Each area should be sampled separately as the soil composition may vary. (Figures 1 and 2)

Obtain a representative sample:

Each soil sample is a combination of multiple sub-samples. When sampling, you’re going to be taking small samples from different spots in your garden/field and then mixing them in a bucket to take a final sample, this is the representative sample.

For larger fields each sample should represent 0 to 10 acres if they have the same or similar soil condition, if the soil is different even in smaller areas, take a representative sample from every different area. 

How to know when the soil is different?

This can be determined by visual appearance or plants behavior, for example: in one area the plants grow healthy and produce a lot during the harvest, while plants from another area can be weak and have low production, in this case you should take a representative sample from each area and test them separately. If not sure about this, you can get this information from soil survey data or by talking to your local cooperative extension expert.

 

Figure 1: Suggested sampling pattern for commercial crops (Author: Dairy-One Cooperative, Inc.)

Figure 2: Suggested sampling pattern for home garden (Author: Dairy-One Cooperative, Inc.)

Avoid sampling these areas:

• CFence lines.
• CWet soil areas.
• CCompost or other topsoil piles.
• CEroded spots.
• CNear roads or highway.
• CBonfires or burning areas.

Prepare the sampling area:

Remove any surface debris, such as leaves or rocks, from the soil surface. This ensures that the sample you collect is representative of the soil beneath.

Start sampling:

• 1.Insert the trowel or sampling tool into the soil at the desired location. Dig down to the desired depth, typically around 6-8 inches. Avoid areas with recent fertilizer or compost application, as they can affect the results.
• 2.Take about ½ to 1 cup of soil from every spot, this will be your sub-sample, put it in a clean bucket. Continue taking multiple sub-samples from the same area and put them together in the bucket.
• 3.After taking all your sub-samples, make sure to mix them together, and take 2-3 cups of this soil and put them in a clean zip-top bag, then label the bag with a permanent marker or paper tag.
• 4.After collecting your representative samples, place them on a paper sheet or newspaper sheet to dry at room temperature. Do not use the oven (rocks in the sample can damage appliances).
• 5.Once dry, put them back in the zip-top bag(s)

How to submit your samples?

Take your representative samples to your local Cooperative Extension Office, they will process the samples appropriately and send them to the laboratory to be tested.

There are different testing methods for soil samples, and each one has a different fee and different results, in order to get accurate results, please provide this information:

• -Sample location: home garden, indoor plants, raised bed, field crop, forest, etc.
• -What are you going to plant there? Mixed vegetables, fruits, flowers, etc.
• -What have you planted there before?
• -Is there any issue with this soil? (Diseases, pests, erosion, nutritional problems, etc.)
• -Soil texture (if known)
• -Is the soil drainage good, regular, or poor?
• -For commercial crops, please provide this extra information: A) crops of the last 3 years, and what you plan to grow there the next 3 years (if you know it). B) Tillage depth (in inches). C) Is there artificial drainage? Does it work well? D) Percentage of legume last year (if known).

When bringing multiple samples, make sure to separate each sample in individual bags/containers, and provide this information for each sample.

…and finally: The results!

After a couple days (sometimes weeks), your results will arrive at your physical address or email address (you decide how to receive them). These results will have the information about your soil sample, depending on the test, you’ll have the information that you requested and the recommendations for your soil (nutrients and pH), and based on these results you can start applying fertilizers or doing amendments to your soil.

Plan ahead, depending on the office where you take the samples, the times to get the results can be longer, they can be as short as 7 days or less, or even a couple of weeks; Before you start applying fertilizers or amendments, call and ask for estimated times to get your results. 

Last updated April 1, 2024