September is a great time to take a soil sample.  The soil sample can be submitted to the Mississippi State University Extension Service for analysis.  The results will serve as a perfect prescription for agricultural lime and fertilizers to allow your plants to reach their potential.   

Failing to take a soil sample can be costly.  Applying fertilizer and lime without the recommendations from a soil test often results in either applying too much, or too little fertilizer and lime.  Applying too much is simply a waste of money.  Not applying enough is withholding the nutrients that the crop plants need to be healthy and productive.

Soil sampling involves taking a small amount of soil that will represent the entire lawn, garden, pasture, or crop field.  The sample will determine the amount of primary plant nutrients including phosphorus and potassium in the soil.  The levels of secondary plant nutrients including calcium, magnesium, sodium, and zinc along with the soil pH will be reported as well.  

While nitrogen is an important plant nutrient, its level is not measured by most soil tests.  Nitrogen levels can fluctuate from temperature changes and soil moisture changes. Recommendations for nitrogen application listed on soil test reports are based on experiment station research trials.  


You might be asking is that a typo?  Is the p lower case and the H capitalized?  Yes, it is correct.  The abbreviation pH refers to potential hydrogen, which is a measure of the acidity or alkalinity of the soil or any other solution.  The pH scale ranges from zero to fourteen, with seven being neutral.  A pH reading below seven becomes more acidic as the reading progresses toward zero.  A pH reading becomes more alkaline as the reading progresses toward fourteen.  There is a big difference between each number on the pH scale.  For example, a soil pH of 5.0 is ten times as acidic as a soil pH of 6.0.

The pH of the soil can affect plant growth and health if it is too high or too low. Plant nutrients become unavailable with extremes in pH. Generally, most plants grow best when soil pH is between 6.0 and 7.0.  There are exceptions to this rule.  Plants including azaleas, gardenias, camellias and blueberries grow best when the pH is between 4.5 and 5.5. 

The pH of acidic soils can be corrected by adding agricultural lime. Soils with pH values that are too high can be corrected by applying a sulfur product.

It is important to note that pH levels do not remain constant.  Soils can become more acidic from rainfall, fertilizer application, and the decomposition of organic matter.  Soil testing every three years can help properly monitor soil pH.

Taking a Soil Sample

The first step in taking a soil sample is to make a plan.  The area being sampled should be divided into uniform areas.  Hilly areas, low areas, or areas with different colored soil, should be sampled separately. 

The next step is to have the proper tools.  You should have a clean bucket, a soil probe or shovel, and one MSU soil sampling box per sample.  Soil probes and the soil sampling boxes are available at the Extension Office. 

The soil should be dry enough to plow before taking a soil sample.  If the soil is too wet the sample will be difficult to complete. 

Soil samples should be taken in random locations in the field in a zig zag pattern. This procedure avoids taking multiple samples in fertilizer spill areas or in strips where fertilizer has been applied in the past.  Row crop fields should be sampled between the rows. Grass or plant material should be cleared away from the spot where the sample is taken.  

Collect fifteen to twenty samples taken four to six inches below the soil surface.  The soil should then be placed in the bucket, allowed to air dry, clods and lumps should be broken up, and thoroughly mixed.  The soil sampling box should then be filled.

The sample should be brought to the Extension Office to be shipped to the Soils Lab for analysis.  The cost of the analysis is eight dollars which should be paid by check or money order. It is recommended to take a soil sample once every three years.  Special conditions such as crop rotation could require more frequent sampling.

During September, don’t forget to take a soil sample to ensure that the next growing season is the best yet.