A soil test is an excellent tool for building soil biology, balancing soil minerals, and growing healthy plants on your farm or in your garden. They can be used to pinpoint nutrient deficiencies or accumulation in your soil, creating a more specific recipe for long-term soil and plant health.
When to collect a soil sample:
Collect soil samples before planting, so that necessary amendments can be added to the soil in time for optimal nutrient integration and solubility. The process can take up to 3 weeks, so be sure to plan accordingly. Following the initial planting, here are some rules of thumb:
- For annual and vegetable crops, test soil annually just before planting – ideally in the late summer or fall.
- For pastures and legumes, test soils every 3 years after planting.
- For perennial crops, ie. Christmas trees, fruit and nut trees, berries and grapes, use annual foliar tissue analysis instead of soil testing. Test soils every 3 to 5 years, or when tissue analysis indicate a need.
How to collect a soil sample:
Use a stainless steel or chrome-plated spade to avoid contamination of the sample. Collect samples into a clean plastic container.
Do not include mulch or vegetation in the sample.
Sample from the depth of the soil where roots will grow. For most annual and perennial crops, sample from 3” down to about 6-8”. Collect and combine 10-20 samples at the same depth from the area that is to be tested. Mix the samples together, and send about 2 cups or 1 pintful of the composite sample to the laboratory.
Bring soil sample and the area of the space you will be planting (sq.ft. or acres) to Concentrates.
A Guide to Collecting Soil Samples for Farms and Gardens by M. Fery and E. Murphy. Oregon State University Extension Service.
Soil Analysis by A&L Laboratories. www.al-labs-west.com