Soil Testing 101
What's in your soil?
Is it everything your plants need to thrive?
Are you maximizing short and long term crop yields and income by properly investing in your soils long term health or are you wasting money and negatively impacting the environment?
If you are unsure, you are not alone. However, a simple, inexpensive soil test can help you make informed decisions to improve the short and long-term health of your soil.
Soil testing is not only a valuable investment in your farm, but we see it as a critical one. Healthy soil is alive. Living things need food to survive. Healthy soil is composed of organic matter, mineral matter, water, and air. The composition of your soil and the resulting bioavailable nutrients influence your crops. Soil composition tells a story of the experience of the lands creation and the history of use of that land.
Because different types of plants need different compositions of bioavailable nutrients to survive and every soil story is different, we recommend you get a soil test for your fields.
One resource for soil testing is the University of Hawaii College of Tropical Agriculture and Human Resources. Extention Agents are a wealth of resources and can walk you through the process for collecting as well as your results. Some information is below was sourced from UH CTAHR and more information can be found here: https://www.ctahr.hawaii.edu/ougc/soil.asp
How to Collect -
Collection is an important part of the process to ensure you get accurate results. Need help? Call UH or us and we would be happy to support you.
(Steps developed by UH CTAHR - extension and West Oahu SWCD - Together We Farm)
Steps: - Use a steel or plastic garden spade or shovel to collect soil cores.
- Collect in areas that have not recently received compost or fertilizers.
- Collect 5 – 10 samples “zig-zag” across the field
- For each sample, dig a hole 8 inches deep for diversified crops. Orchard crops need two samples - one collected at 8" and one collected at 20". Cut a 1-inch thick slice from the top to bottom of the hole.
- Take a 1" wide by 1" thick segment of the slice, and place it in a clean mixing bucket, preferably made of plastic.
- Mix all 5-10 samples in a bucket.
- Place 3 cups of the well-mixed soil in a clean ziplock.
- Label with field name
- Fill out the Soil Information Sheet and submit it with your soil sample to the drop off site at the Pearl City Urban Garden Center.
For information on how to take a soil sample, view the guide on this website http://www2.ctahr.hawaii.edu/tpss/research_extension/rxsoil/soilsample.htm
Plan to collect soil samples two to three months before planting so you will get your test results in plenty of time to plan your liming and fertilization. Depending on workload, the turnaround time at the lab can be up to two-three weeks. Soil in fields or gardens should be tested at least once every two years.