Petersburg, West Virginia. Petersburg is a city in Grant County, West Virginia, USA. The population was 2,467 at the 2010 census. It is the county seat of Grant County. Contents.
The particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Although a soil could be all sand, all clay, or all silt, that's rare. Instead most soils are a combination of the three.
Soil is essential for plant growth for several reasons. Soil provides plant roots with nutrients, water and air. Soil also serves to anchor the plant. There are different types of soil, and it is very common to find the foundation soil around your house to differ from your property line soil. Soil is comprised of three mineral particle sizes: sand, silt and clay. Large, course mineral particles are sand, fine mineral particles are silt, and very fine mineral particles are clay. An ideal soil is composed of 45 percent mineral (sand, silt and clay), five percent organic material (humus or plant debris and soil organisms), 25 percent water and 25 percent air.