In the class,  guest speaker James Adkins,  works at the UD research farm, had talked about the development of irrigation system.  Water is an essential part of farming. In the past, irrigation systems were not developed well, so they may wast water and cost more for a long term. Over time, the irrigation system has been improved.  It not only save the water resource and prevent pest and disease problem.  it does good and efficient work.  There are some areas are lack of water resource, like California. Advanced irrigation system gives a big help! The soil quality could tell how much water needed. after this lecture, i understand how important the combination of water and soil. and how important the soil and water mean to farmland.