Like farmers, vegetable gardeners sometimes work in the rain in spring in order to get their favorite seeds and plants in the ground on a timely basis. In a wet spring, when repeated rainfall events do not allow for soils to dry out in a timely manner, some farmers and vegetable gardeners choose to plant in saturated soils. Farmers call this practice “mudding the crop in.” Unfortunately, working in wet soils can cause damage to soil structure and soil quality that can negatively affect crop yield for years.
Ask the Expert:What is the best way to control moss in your lawn?
Pore space critical to healthy soil
Healthy, well-functioning soil should contain 50% pore space by volume in order to hold moisture, oxygen and other gases. The other 50% of soil is made up of mineral particles (45%) and organic matter (5%). Pore space is critical for drainage, moisture retention, nutrient availability and proper root development.
When gardeners work wet soils, they can easily compact soils, eliminating critical pore space. While it is easy to understand how heavy power garden equipment such as tractors and tillers can compact wet soils, the very act of a gardener walking on wet soil can cause compaction. When compacted soil dries out, the mineral particles and organic matter remain cemented together, and the pore space does not return.
The negative effects of soil compaction tend to be more pronounced on heavier clay and shale-based soils, than on lighter soils, which have a greater proportion of sand particles. The loss of pore space affects the ability of soils to drain properly and store moisture and oxygen. Compacted soils also make it more difficult for roots to penetrate the soil and develop extensive root systems needed for maximum growth and production.
More from Mike Hogan:These deer deterrents can lessen damage to your vegetables and flowers
Organic matter important
The negative effects of compacted soils can be minimized by the presence of higher levels of organic matter in the soil. Depending upon location and how soils have been managed, native soils in Greater Columbus may have just 1 to 3% organic matter. Anything a gardener can do to add organic matter to their garden soil will provide a multitude of benefits. Examples of appropriate sources of organic matter include compost, wood chips, paper and cardboard, straw, livestock manure and cover crops. Gardeners interested in knowing the level of organic matter in their soil can have their soil tested for organic matter.
Wet soils in raised beds
One of the benefits of gardening in raised beds is that foot traffic is eliminated in the bed, allowing gardeners to work in wet soils without the threat of compacting the soil. That is one reason why raised beds should never be more than 48 inches wide, allowing gardeners to perform all tasks in the bed while standing outside of the bed. Raised beds designed for youth should be no more than 36 inches wide to allow smaller children to perform gardening tasks without standing in the bed.
When faced with the choice of working saturated soils or delaying planting, gardeners should opt to wait out the weather and stay off wet soil.
Mike Hogan is an Extension educator, Agriculture and Natural Resources, and associate professor with Ohio State University Extension. hogan.1@osu.edu