soil sampling for fertility plan growers

4 Reasons to Consider Annual Soil Sampling

by Wilks Wood, Ph.D. – Field Agronomist, Growers

The best way to create a confident fertility plan is soil sampling. That’s what we do for all our farmers. 

Even though soil fertility is an essential factor in row crop production, many farmers only have a general idea of their soil nutrient values. Overlooking this step can cause a loss in crop production and unnecessary fertilizer applications.

For just a few dollars an acre, you can use soil sampling test data and make educated decisions about applying nutrients (that can often cost as much as $100 an acre).

We’ll walk you through in detail the top four benefits of performing annual soil sampling. 

1. Annual Soil Sampling Provides Answers to Nutrient Questions

While soil sampling is a valuable practice at any time, it’s especially useful during periods of lower commodity prices. Testing data will provide the information you need to create a smart fertility plan.

Do you often wonder if:

  • You have enough phosphorus or potassium to reach your yield goal?
  • Last year’s crop removed as much as you think or is there some residual left in the soil?
  • How much of your potassium leached due to the rain this year?
  • Did more of your phosphorus mineralize this year that you can use?

When you conduct soil testing every year, you eliminate the guesswork. You can know for sure if you need to reduce or increase inputs, especially across different fields. 

2. Changes in Yields Signify Changes in Your Soil Fertility

A common practice in the farming community is to have soil sampled every three to four years. However, soil samples taken more than a year ago will have limited value. 

If yields have consistently increased or decreased by even a few bushels since the last time you sampled, the information for next year’s crop is outdated. Increased yields require and use more nutrients, while decreased yields require less.

Because soil nutrients change from year to year, you can’t use the same products and rates on every field and expect to experience consistent yields farm-wide. Your farm’s fertility program is far too large of an input for you to be confident about what’s required for one year, and then make assumptions over the next two to three years.

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3. Pitfalls of Using Outdated Data to Make Current Decisions

We had a client that typically sampled every four years. After discovering that potassium was a limiting factor on his farm, he spent the next two years focusing on building potassium levels. 

We began working with the farmer in year three of his four-year cycle and collected soil samples as part of our information gathering process. The farmer had done such a good job, there was excess potassium in the soil, which was beginning to negatively affect phosphorus uptake. 

Without soil testing data, he would likely have applied more potassium that year, which would have been an unnecessary expense and negatively affected yield.

What happened on this farm is easily representative of similar situations that can occur on any farm from year to year. Sampling every year allows farmers to rely on solid data and takes the guesswork out of planning. 

If you suspect certain nutrients are limiting or think an interaction is occurring in the soil, sampling every year will provide the answers. You can implement changes in a more timely manner and utilize the soil as a true investment.

4. Investment Will Pay Dividends in Increased Yields and Decreased Fertilizer Use

In prior years, perhaps it made sense to build up soil nutrients across the farm. These days, farmers need to find ways to control the budget and lower production costs. 


By using outdated soil data, you won’t know what the soil needs from year to year. Regular soil testing can provide information about soil-nutrient availability, improve fertilizer use efficiency, and increase crop productivity. Want to stop guessing about what your soil needs?  Call us at 984.500.3797 or visit https://www.growers.ag/contact/. We’ll review your soil sampling schedule to help you find ways to be more productive and profitable.