A soil's type is important to understand when considering potential foods it may grow or when considering building a structure and whether the soil beneath will sufficiently support it. Pennsylvania has several soil types including glacial till, sandy loam, silt loam and coastal sand.
Glacial till is a mixture of clay and rock boulder-size particles that have been deposited beneath or mixed with glacial ice. The receding of the glaciers that once covered North America thousands of years ago left behind glacial till soil, which is in northwest Pennsylvania. Glacial till soil makes growing crops hard because of the slow drainage of the soil and the difficulty plant roots have in finding water.
A sandy loam soil drains and tills easily because of its sandy nature. The soil has a smooth texture which crumbles well. This makes sandy loam an ideal garden soil. Sandy loam soils are found in the north-central Pennsylvania area, primarily the Allegheny high plateau. This area has a brief growing season and plants may have difficulty developing adequate root systems because of the presence of rock fragments in the soil. In the Allegheny Mountains, there is a high potential for soil erosion because of the steeply sloping land. Sandy loam soils are also found in eastern Pennsylvania's various valleys and ridges.
Silty loam soil consists of particles smaller than sand particles and larger than clay particles. Silt is often found on riverbanks and shores and is highly fertile. Silt loam soil is found in southwest and central Pennsylvania and in the Conestoga Valley region. The most agriculturally productive area is the southwest region where the soil tends to be deeper.
The coastal sandy soil is around the city of Philadelphia and the surrounding area. Sand particles are larger than those detected in silt and clay soil, allowing water and nutrients to leave the soil more readily. This causes the soil to lose nutrients. The coastal plains have a longer period growing season than other Pennsylvania regions because of the warmer temperatures along the coast.
