Water Research and Management : Current Status and Needs for the 21st Century

Quantitative system approaches, provided by process‐based models of agricultural systems, are essential for optimizing the use of increasingly limited water and soil resources, guiding tactical management, and addressing the environmental concerns and global issues of the 21st century. Agricultural engineers have made significant contributions in the past to model development and applications in soil and water research, irrigation design, and water management, and they are uniquely capable of making the much‐needed and exciting further model enhancements. In this brief review, we present: (1) the current status of system model development and applications in soil and water research and management, with examples from the USDA‐ARS Root Zone Water Quality Model (RZWQM); (2) lessons learned from RZWQM development and applications; and (3) future needs and directions in system model enhancements and applications to make them more effective. We make a strong case for international collaborations among modelers and experimentalists and for a common development/applications protocol and platform for the future.