Why is soil porosity influence to plant growth and development?

A sandy soil is quick draining, but may be poor in nutrients. A clay soil is poor draining, and may be waterlogged for long periods. Though clay soils may be richer than sandy soils in nutrients, having waterlogged roots may rot off a plant's roots. A well draining, nutrient rich, loamy soil will hold water, yet drain enough to avoid root rot, so allowing the plants to thrive.