As winter starts to turn to spring each year, I begin getting questions from ag producers and homeowners alike on what they should fertilize with and how much they should use. I usually answer them by asking them a series of questions to figure out their own personal situation, but the conversation usually ends with me recommending that they do some soil testing. Without knowing what the nutrient levels are in the soil, it is impossible for anyone to really know what to recommend. So, since we are 4-6 weeks out from optimum fertilizing time, I thought this would be the perfect time to discuss soil testing.
Why do soil testing?
Proper soil fertility is the foundation for plant health; soil pH and nutrient levels vary greatly from site to site. Turfgrass, shrubs, flowers, fruits, vegetables, pastures and rangeland all have specific nutritional requirements. Soil testing is an important diagnostic tool to help ensure the proper amounts of fertilizer are applied. Both over and under applying fertilizers wastes time and money and gives poor results. Over-application can also harm the environment, especially surface and ground water.
What a soil test shows
A soil test conducted through the Texas A&M AgriLife Extension Service Soil, Water and Forage Testing Laboratory will measure soil pH, available nitrogen, phosphorus, potassium, calcium, magnesium, sodium, and sulfur. Upon request, it will also measure salt content and the micronutrients copper, iron, manganese, and zinc. The report will also include custom recommendations as to which nutrients – and how much of each – should be applied to healthy plants in the landscape, vegetable garden, fruit orchard, or range and pasture. Soil tests can also be obtained through other sources such as ag businesses that sale and apply fertilizer.
When and how often?
Have the soil tested if it has never been tested before. Otherwise, have it tested at least every 3 years unless management techniques have changed. The lab is open for soil testing all year long. Testing the soil in the fall/early winter after crops have been harvested is a nice habit for closing out one growing season and getting ready for the next and also beats the spring soil testing rush. For sure you will want to send in your soil test 2-3 weeks prior to the anticipated fertilizer application date so that you can ensure that you receive results in time.
Where to get bags
Soil sample bags, information sheets, and submittal forms are available from the DeWitt County Extension Office in Cuero. Also, soil sample bags, information sheets, and submittal forms are available at other County Extension Offices throughout the state. Thirdly, the information sheets and submittal forms are available online on the Texas A&M AgriLife Extension Service Soil, Water and Forage Testing Laboratory website at https://soiltesting. tamu.edu/. As stated earlier, soil tests can also be obtained through other sources such as ag businesses that sale and apply fertilizer. Arrangements for sample bags and submittal forms will have to be made through them.
Don’t Guess – Soil Test!
Some of the best time and money spent on home lawns and gardens, and range and pasture is the relatively small amount needed to test the soil.
This article was adapted from the “Soil Testing” page on the Henderson County, Texas Master Gardner Association website.
