What Is Loam and Loamy Soil?

Soil Texture Basics

• Sand, the largest type of soil particle, feels gritty to the touch. Sandy soils have good aeration but don't hold water well. Silt particles are smaller than sand and are smooth, but not sticky. Clay particles are the smallest and feel sticky to the touch. Clay soils retain water well but don't allow for air circulation, which makes it difficult for plants to grow.

Types of Loam

• Loamy soils are categorized by their proportions of different soil particles. For example, loamy sands are mostly sand but contain some silt and clay. Clay loam has even proportions of sand, silt and clay but feels sticky when wet. Silty loam is mostly silt but also contains clay and sand. You can find the proportion ranges of silt, clay and sand in different types of loam, such as silty clay loam and sandy clay loam, by examining a USDA diagram called the "Soil Textural Triangle."

Identifying Texture

• If you're unsure what type of soil you have, squeeze a clump of moistened soil into a ball, open your hand and determine how easily the ball breaks. Soils that have a coarse texture, such as sand and loamy sands, will break easily. Sandy loams and silt loams, which have a medium texture, will change shape easily and won't break as easily. Clays and clay loams, which have a fine texture and generally feel sticky, resist breaking more than other textures.

Amending Soil

• Adding soil amendments to the soil improves its texture. For example, if you have a sandy loam soil, soil amendments help your soil hold more water. If your soil is a clay or silty loam, amendments increase air circulation and make soil less sticky. Common soil amendments include compost, aged manure, sphagnum peat, wood chips or hardwood bark. Determine your soil texture before adding amendments so you can determine which amendments will be most effective.