Field Test for Soil Types

Soil Components

• Soil is much more than mere dirt; it is a complex blend of air, water, organic materials and naturally occurring minerals; however, the majority of soil is made from rocks that have broken down over time. The tiny particles that remain are divided into three main categories: sand, silt and clay, with sand being the largest and clay being the smallest. The soil type in any given garden is determined by the comparative quantities of these particles.

Soil Types

• The ideal soil for a garden is made from 40 percent sand, 40 percent silt and 20 percent clay. This soil type is known as loam. It drains well, is easy to work with, is fairly high in nutrients and is loose enough for roots to penetrate. However, most gardens do not contain perfectly balanced loam. Soils with a higher percentage of sand tend to be loose and dry, while those with a higher percentage of clay tend to be tight and moist. Accordingly, most soils are roughly classified as sandy, loamy or clayey.

Field Test

• To determine a soil's type, simply grab a handful of loose dirt, moisten it slightly and squeeze. If the soil forms a tight ball, it is clay. If it holds its shape, but crumbles around the edges, it is loam. If it will not form a ball, it is sand.

Amendments

• While there is little that can be done to permanently alter a soil type, both sandy and clayey soils can be improved by working organic materials, such as mature compost or rotted manure, into the soil each spring. Not only do these materials provide nutrients for nearby plants, they help bind particles together, improving the structure and texture of the soil.