To eliminate much of the guesswork involved in creating a fertilization program, we strongly encourage you to test your soil. Soil tests provide both a detailed analysis of soil nutrient levels and specific fertilizer recommendations. The recommendations are based on information that you provide. Standard soil testing is free of charge, compliments of the North Carolina Department of Agriculture. The following tips should help you get started.
1. Frequency - For most cultivated landscapes, the soil should be tested every three years.
2. The first step in the testing process is to obtain sampling boxes and information sheets. The boxes and sheets are available from your local NC Cooperative Extension Service office and many area garden centers.
3. Where to sample - Because plants have different fertility requirements, separate samples should be taken for different plant groups. Recommendation rates will vary based on plant type, so take an individual soil samples for your vegetable garden, roses, shrub beds, lawn, etc�.
4. How to sample - Use a hand trowel or shovel to remove a soil core to a depth of eight inches. Place the core in a clean plastic bucket. Metal buckets can not be used. Take a total of ten core samples from each test area and mix them thoroughly in the bucket. Remove any rocks or organic matter, such as twigs or grass roots, from the bucket. Use this soil to fill the sample box about 2/3rds full. Write your name, address, and sample number on the box. Because memories quickly fade, write down the sample locations and each corresponding sample number. This is invaluable when it comes time to read the soil report.
5. Fill out the information sheet according to the directions. For homeowners, the crops codes of relevance are 020 through 031.
6. The soil sample boxes and information sheets can be mailed to the NCDA, but you can also drop them off at the Cooperative Extension Service office. Local agents regularly take the sample boxes to the NCDA.
7. North Carolina farmers send in thousands of samples to be tested each year. This primarily occurs during the winter. Because of the massive inflow, testing takes longer in the winter and early spring. It generally takes 2-4 weeks to get the results back. A pamphlet is included with the soil report that makes interpreting the information quite manageable.