ABSTRACT
The objective of this chapter is to review the progress and challenges in the research for improving yield and water use efficiency (WUE) in three major crops in the US Southern Great Plains (SGP) region. The major data source is from the research conducted in Texas High Plains over the last 50–60 years along with some research conducted in other areas of the SGP region. The major challenge for dryland crop production is the development of management practices for efficient use of soil water storage as well as growing season precipitation. The closer relationship between WUE and harvest index (HI) in wheat was also reported in North China Plains and Mediterranean environment. Under water-limited conditions during crop growing season, soil water must be conserved before flowering so that it can be used for grain filling and maintaining HI. Greater yield is associated with a greater ability to effectively use soil water, particularly the soil water at deeper profile.
