Soil testing and amending

If you're concerned about the soil quality in your landscape -- whether turfgrass, ornamentals or vegetable garden -- a soil test can give you basic information to help you improve it. Soil testing isn't very expensive or difficult and can be done anytime the soil is not frozen.

Decide how many soil samples are necessary for your landscape. One sample usually is sufficient for most landscapes unless there are obvious soil differences; then each unique area should be sampled separately. It also can be beneficial to sample areas separately based on their usage, so that samples are submitted individually for turf, ornamentals and vegetable gardens.

Create your soil sample by taking 10-15 soil cores from random locations in the sampling area. If you don't have a soil probe, use a shovel to collect samples at a 5- to 6-inch depth. Remove any vegetation or thatch from the cores and combine them into one container. This aggregate collection is your sample. Place 1 to 2 cups of well-mixed soil in a plastic bag or the sample container provided by the lab.
Choose a test that will give results for residual nitrogen, phosphorus, potassium, organic matter, cation exchange capacity (CEC) and soil pH. Your soil test results usually will arrive in about two weeks, along with recommendations for soil amendments based on the plant types you indicated on the submittal form.
If you have questions about reading the soil test results or potential soil amendments for your garden, call your Local County Extension office.

Tips for Soil Amending

* Soil amending can be done in spring, but don't work the soil when it is wet to avoid soil compaction and the creation of hard clods. Fall is an excellent time for soil amending, because it allows time for the soil structure or chemistry to change before a new growing season begins.

* Organic matter breaks down over time, so raising and maintaining your soil's organic matter content will require repeated amendment.

* Keep in mind that Nebraska's clay soils have a high buffering capacity -- or the ability to revert to the original pH level after amendment with sulfur. Maintaining a lower soil pH will require repeated amendment.

Another great resource is the publication "Fertilizers for Vegetables in Home Gardens," which contains detailed information on adjusting soil pH, amending with organic matter and adding fertilizer. It's available at www.ianrpubs.unl.edu/sendIt/g945.pdf or from your Local Extension office.