Search news

Good topsoil can be key in renovating lawns

Media contact:

Robert E. Thomas
Information Specialist
University of Missouri Cooperative Media Group
Phone: 573-882-2480
E-Mail: thomasr@missouri.edu

Published: Tuesday, September 29, 2009

Story source:

Manjula Nathan, 573-882-0623

COLUMBIA, Mo.—Fall is a time when homeowners get ready to renovate lawns.

“One dilemma homeowners face is how to choose good topsoil with the proper characteristics,” said Manjula Nathan, University of Missouri Extension soil specialist.

Topsoil is available either bagged or in bulk. Bagged topsoil usually comes in 40- to 50-pound quantities and is amended with lime, fertilizer and organic matter. Bulk topsoil generally is native soil taken from the surface and sold in truckloads, Nathan said.

“Although most surface soils have higher organic matter content than subsoil, not all surface soil is ideal for your garden or lawns,” she said. “You should ensure that the topsoil you are buying has suitable physical and chemical properties for your purpose.”

The three main chemical and physical properties that influence topsoil quality in Missouri soils are pH, texture and organic matter content.

Soil pH is a measure of the acidity or alkalinity of soil. Soils with pH values below 7.0 are acidic; those above 7.0 are alkaline. If you are going to test your soil pH yourself, use a pH electrode; paper test strips will not accurately measure soil pH.

“Ideal pH is between 5.5 and 7.5,” she said. “A wide variety of plants will grow well in this pH range. However, some acid-loving plants like azaleas, rhododendrons, blueberries and raspberries prefer pH below 5.5.”

Soil texture refers to the proportion of sand, silt and clay-sized particles in soil. Texture influences water-holding capacity, aeration, drainage, tilth, compaction and nutrient-holding capacity.

“Ideal soil texture is loam and silt loam,” she said.

Organic matter is essential in the formation of soil structure, reducing compaction and retaining plant nutrients. Ideal organic content is 3 percent or greater.

A soil test is the most reliable way to determine the quality of topsoil. If you are buying a lot of topsoil, have it tested to check soil pH, texture, organic matter content and nutrient levels.

Soil testing is available through local MU Extension centers or from the MU Soil and Plant Testing Laboratory. For more information, contact the lab at 573-882-0623 or soiltestingservice@missouri.edu, or visit the lab’s Web site at http://soilplantlab.missouri.edu/soil.

Additional information is available in the MU Extension guide “Soil Testing for Lawns” (G6954), available for purchase or free download at http://extension.missouri.edu/publications/DisplayPub.aspx?P=G6954.

###