What Is Loam in Soil?

Definition

• Loam is not a primary soil type nor is it a type of earth soil. It's a fertile combination of the three major soil particles -- clay, silt and sand. In most cases, loamy soil effectively absorbs and retains water. It has several variants depending on its sand and clay base. The amount of clay and sand in loamy soil determines its ability to absorb and retain moisture.

Characteristics

• Loams have a plastic appearance, especially when moist. They usually appear dark brown or black. Loamy soil has grainy or coarse appearance that's soft and feathery to the touch. It has a loose and rich appearance. Loamy soil forms into a loose ball when squeezed and crumbles easily by a poke of a finger.

Benefits

• Loam's dark, moist and porous nature offers good drainage. Often, plants dwelling in soils that effectively retain and drain water are healthy and productive. Gardeners often look for good soil characterized by substantial moisture of sand, silt and clay. Good garden loam offers ease of maintenance and soil workability. The natural elements in loamy soil make it the most suitable lifetime partner of a healthy plant ecosystem. These natural elements consist of bacteria, fungi and earthworms. These organic soil dwellers when combined act as decomposers breaking down plant and animal tissue to form humus. Humus helps in roots grow and effectively retains water and air.

Preparation

• Most gardens are not ready for planting. Improving the soil's workability enhances a soil's ability for gardening. Preparing the soil with the right amount of clay, sand and humus produces loamy soil. For new gardens, add an extra application of humus every year to keep in moisture. Add soil amendments with a mixture of 4 to 6 inches of organic material into the top 6 to 12 inches of the garden soil to sustain the soil's nutrients. According to Texas A&M University, the ideal soil chemistry should have a combination of 2 to 4 meq/100 g, silt 4 to 10 meq/100 g, clay 10 to 100 meq/100 g and organic matter 150 to 300 meq/100 g.