Get the dirt: Knowing the soil is crucial to gardening

Getting to know the soils in the yard or garden can provide insights into what their physical and chemical makeup is in terms of texture, color and organic content, depth, water holding capacity, and structure. Figuring out and knowing soil types can help us determine what they are capable of growing or are best suited for, how they should be managed to remain sustainable, and what their limitations are to name a few properties.

Identifying soil types is a first step to understanding their potentials. Once the basic characteristics are known it is easier to develop plans for managing them. For example, many of our Grant County and Adams County soils consist of sandy loam and silt loam textures, are relatively low in organic matter (1% or less in the native state), tend to be neutral to moderately alkaline (7-8+ pH range), and may not need to be watered as often as soils that consist entirely of sand. Some soils have limiting features like high water tables, are shallow to basalt bedrock or caliche (a calcium carbonate cemented layer), or have high percentages of sand and gravel (2 millimeters to 3 inches in diameter) or cobbles (3-10 inches in diameter), stones (10-24 inches in diameter) or boulders (more than 24 inches in diameter) in the soil profile. Examples of very sandy soils are primarily in the Black Sands area (Irrigation Block 89) near Dodson Road west of Moses Lake and north of Lind Coulee off state Route 17, peaty (organic) soils occur near Wilson Creek in the Crab Creek floodplain and deep windblown rock-free loess soils are in the Hartline area south of Coulee City, and in the Beezley Hills north of Ephrata. Fine textured soils are present south of Lind Coulee off Highway 17, close to Quincy and along the Royal Slope and there are gravelly and stony soils in the Moses Lake-Ephrata-Soap Lake areas.

Soil scientists from the USDA Natural Resources Conservation Service mapped the soils in Grant and Adams Counties using standardized nationally recognized principles which were correlated using a taxonomic system specifically designed for soils. Gardeners are encouraged to view hard copies of the Soil Survey of Grant County, Washington, published in 1984 or the Soil Survey of the Adams County, Washington, 1967 available through the U. S. Department of Agriculture, Natural Resources Conservation Service or the public library. Alternatively, there are easy-to-access online resources to use to learn about soils throughout the United States. Simply go to Web Soil survey at http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm or Soil Web http://casoilresource.lawr.ucdavis.edu/soilweb-apps/ to find out what the soils are on site-specific locations and on individual properties. Master Gardeners can assist gardeners in determining what your soils are like and what they can best grow, and offer suggestions about what to do to improve them.

For gardening questions contact the WSU Grant-Adams Master Gardeners at the WSU Grant County Extension office at 754-2011 ext. 4313. Our online reference services are available at http://ext100.wsu.edu/grant-adams/gardening/. Email ga.mgvolunteers@wsu.edu to contact one of the many Master Gardeners on call 24/7 year-round to answer gardening questions.