Agronomic Services — News ReleaseFOR IMMEDIATE RELEASE
FRIDAY, NOVEMBER 17, 2006
Contact: J. Kent Messick, Field Services Section Chief
NCDA&CS Agronomic Division
Making your own soil mix? Help is available
ASHEBORO—At a nursery trade show last fall, Al Morton stopped at a N.C. Department of Agriculture and Consumer Services booth to ask about soil testing. This is a routine inquiry at plant-oriented trade shows, but a little out of the ordinary for Morton, who runs and operates a construction-demolition landfill.
"I get leaves, tree limbs and storm debris from the City of Asheboro," said Morton. "I've been making mulch for six years and compost for three. This year I developed a soil mixture that I wanted to market commercially. I wanted it tested so my customers would know exactly what they were buying. I wasn't exactly sure how to go about it though."
At the trade show, Morton was directed to the NCDA&CS Agronomic Division booth. There he found the information and materials he needed—instructions on how to take samples, sample boxes, forms and mailing addresses. Best of all, however, was the news that someone would visit his operation, walk him through the sampling process and help him make sense of the results. Within the week, NCDA&CS regional agronomist David Dycus showed up at Gold Hill Landscape Supply to offer assistance.
Dycus toured Morton's operation and advised him to submit separate samples of each ingredient in his soil mix as well as samples of the final mixture itself. Morton's Super Blend consisted of equal amounts of finely decomposed leaves, topsoil and mushroom compost.
"I made sure Morton submitted the soil samples for diagnostic analysis so he would receive information on soluble salt content, which is not measured by routine soil tests," said Dycus. "Soluble salts can be problematic in any product containing composted material."
Morton also submitted samples of the mushroom compost for waste analysis. Mushroom compost is a product that Morton had heard good things about. A by-product of the mushroom production process, it is a blend of composted wheat straw, hay, corn cobs, cotton seed hulls, gypsum and chicken manure. Morton had paid top dollar and trucked it in from Pennsylvania.
"For a product like mushroom compost, waste analysis is the best tool for measuring nutrient levels," said Dycus, "because it actually measures available nitrogen. Soil tests don't typically measure nitrogen because it moves readily out of the root zone with normal rainfall. Organic composted materials that have been somewhat protected from the leaching effects of rain can still contain significant amounts of nitrogen."
A few weeks later, the two men met again to go over the test results. The topsoil and decomposed leaves had nutrient values within ranges suitable for plant growth. The waste report for the mushroom compost, however, indicated excessively high values. The soil report for the final, blended product indicated a relatively high pH (7.0) and very high nutrient levels. If plants had been set straight into Morton's Super Blend soil mix, the high salt content would have damaged, and perhaps killed, them.
Dycus suggested modifying the blend so it contained only 10 or 20 percent mushroom compost. Following this advice, Morton developed six new recipes. Within a few weeks, he had a new, agronomically sound formula for his Super Blend.
"Our tests show that Morton's product is very consistent even though he doesn't have a bulk blender," said Dycus. "He's not shooting in the dark. His customers know what they're getting."
Trying to decide whether soil testing or waste analysis is the most appropriate tool can sometimes be confusing. However, the NCDA&CS Agronomic Division's Field Services Section offers advice and assistance in all aspects of crop nutrient management and agronomic testing, including soil testing, nematode assay, and plant, waste or solution analysis. Growers in Anson, Guilford, Hoke, Lee, Montgomery, Moore, Randolph, Richmond and Scotland counties can contact David Dycus at (919) 776-9338 or by e-mail at firstname.lastname@example.org. Growers in other N.C. counties can visit the Web site www.ncagr.com/agronomi or contact Kent Messick at (919) 733-2655 for the name of their local regional agronomist.