The soil environment

This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book attempts to summarize the state of the art and science of drainage. Agricultural drainage may be described as the removal of excess water from land to promote agricultural production. This facile definition may not be incorrect, but it tends to hide more of the issue than it illuminates. The primary purpose of drainage is to provide a soil water condition that is favorable for crop growth and soil management. Removal of excess water helps dry the soil early in the season, making it possible to prepare the soil for planting earlier and thus lengthen the growing season. It provides traction for farm equipment and mechanical strength to reduce compaction. It also warms the soil to aid early plant growth. The most important objective of drainage in humid regions is no doubt to provide desirable aeration conditions.