Soil sampling is the foundation for nutrient management. Producers use this information to make fertility decisions for their operation to reduce production cost. A soil test eliminates guesswork and allows producers, agronomist and educators to make sound fertility recommendations and decisions. A soil test can often be time consuming but will pay off in the end. There is no need to apply a nutrient unless you need it to reach a specific yield goal for a particular crop. Here are some common questions and answers regarding soil testing:
What is a soil test?
A Soil Test is a process by which nutrients are chemically removed from the soil and measured for their plant available content within the sample. The quantity of available nutrients in the sample determines the amount of fertilizers needed for a particular crop. A soil test also measures pH and the amount of acidity within the soil to determine if lime is needed and how much should be applied.
How often should a soil be tested?
A soil test should be conducted if fertilizer is going to be applied or when problems occur during the growing season. Once every year is recommended when nitrogen fertilizer is applied, and at least once every three years if P and K are concerned.
When is the best time to take soil samples?
Soil samples can be taken any time throughout the year and tested for pH, phosphorus and potassium status. Collect soil samples 1-2 months before planting. Early spring is a good time to take soil samples for summer crops, and summer is a good time to sample for fall and winter crops. This allows time for lime recommended to react with the soil and change the pH before the crop is planted. To assess soil available nitrogen, sample as close to planting as possible. For Lawns, the late spring (May) is a good time to sample for warm season grass and the summer (mid-Aug) is good for cool-season grasses.