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Fall – Time to Get a Soil Test

Soil Testing

Tracy Allen, Supervisor of Soil Testing Lab at Umass

“This is the best time to test your soil,” Tracy Allen, supervisor of the University of Massachusetts Soil Test Laboratory, told me as she showed me around the very clean room filled with lots of boxy equipment and various kinds of glass beakers. “We run about sixteen to eighteen thousand soil tests a year, and most of those requests come in between April and June. We are really busy then, and people won’t get their test results as quickly.”

She showed me the many different types of equipment used from the ovens that dry the soil samples when they first come in, the sieving machine that shakes out sand and gravel, and the machine that creates the soil extracts that are tested by a spectrometer to identify 16 nutrients in the soil. It became clear to me why it takes time to get an accurate and useful test result.

During our years in Heath I sent an occasional soil sample to the lab. Instead of spreading around a 5-10-5 fertilizer around, I knew I was adding my own N-P-K fertilizers. There was nitrogen from my composted chicken manure, phosphate rock for phosphorus, and greensand for potassium, but I didn’t know whether my soil needed more of specific nutrients. The Umass test results not only told me the measurements of these three main necessary nutrients, they gave me a measure of the important trace elements like magnesium, manganese and boron, as well as the organic material in my soil. They also gave recommendations for improving the soil. One of the advantages of using organic fertilizers is that they work slowly, feeding plants over time, not giving them a big rush all at once. The brief saying “feed the soil, not the plant” has been my guide.

The Umass soil testing lab makes it possible to efficiently choose fertilizers to improve your soil. It also gives warnings of lead or other heavy metals that might be in the soil. If you are growing vegetables, you do not want them taking up these heavy metals and serving them at the dinner table.

Soil Extracts ready for the spectrometer

As we walked past the various machines Allen explained that while at least 50 percent of the test requests were for home gardens, they also got requests from landscapers, golf courses, and construction companies. I could understand the needs that landscapers and golf course staff would have but Allen had to explain that construction companies needed to know the soil composition before they put down any paving. The lab has special tests for greenhouse operators who need to know the makeup of the soilless media they use for their crops.

The lab has a website which offers a downloadable test form and complete directions for taking a soil sample. It is important to take your sample carefully. Use a clean pail and clean tools to collect 12 samples from different areas of your garden. Each of these sub-samples should be six to eight inches deep. Do not take samples when the soil is very wet.

Mix all the sub-samples together, removing stones and other debris. Take a cup of the mixed samples and spread on a piece of clean paper to fully dry in the air. Do not use heat to dry the soil. Place the cupful of air dried soil in a labeled zip lock plastic bag. Print and fill out the downloadable submission form. Label your sample. I used my last name and the designation ‘vegetable garden.’

The routine soil analysis costs $15. The results will list pH, nutrient levels including phosphorous and potassium, as well as the important trace elements of calcium, magnesium, iron manganese, zinc, copper and boron. The test will also measure the heavy metals lead and aluminum. It is these measures that make it possible to give recommendations for adjusting pH and adding fertilizers.

There are additional tests. I always wanted to know the level of organic matter in the soil. This test costs an additional $6. Farmers might be interested in other more specific tests. If you are asking for multiple tests, for example if your front and backyards seem to have very different qualities, there is a cost for each sample bag.

Downloadable testing request forms are available at http://soiltest.umass.edu.

The lab does not accept credit or debit cards. Send a check with your sample for the proper amount made out to the University of Massachusetts to 203 Paige Laboratory, 161 Holdsworth Way, Amherst, MA 01003

Umass has other resources for the home gardener through the Extension Outreach programs available through the soil testing lab website. These include various Fact Sheets, and a subscription to Clippings newsletter. You can also send your garden questions to greeninfo@umext.umass.edu.

UMass Garden Calendar

UMass Garden Calendar 2018

Gift giving season is upon us. UMass Extension puts out a beautiful and useful calendar every year. There are gorgeous flower photographs, and useful information for every day of the year. The 2018 UMass Garden Calendar includes a featured article about Insects to Look for in Massachusetts which, along with a short segment on beneficial pollinators, presents key information on, and photos of current invasive insects of note. Calendars are $12 each. You can order online with a credit cared by going to https://ecommerce.umass.edu/extsales/. Add shipping of $3.50 for one calendar and $2.00 for each additional calendar up to nine.

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