WATERLOGGING AND EXCESS SALINITY IN IRRIGATED SOILS IS A MAJOR IMPEDIMENT TO INCREASED PRODUCTIVITY OF AGRICULTURAL SYSTEMS IN MANY DEVELOPING COUNTRIES. REMOVING THIS IMPEDIMENT REQUIRES A METHODOLOGY FOR THE SYSTEMATIC STUDY OF THE NATURE, SERIOUSNESS, AND SOURCES OF THE PROBLEM. THIS THESIS ATTEMPTS TO DEVELOP SUCH A METHODOLOGY BY DRAWING ON EXISTING KNOWLEDGE AND INCORPORATING IT INTO A LOGICAL INVESTIGATIVE FRAMEWORK. FIRST PRESENTED IS BACKGROUND INFORMATION IN THE FORM OF A MODEL OF HOW AGRICULTURAL WATER IS USED, FOLLOWED BY A DESCRIPTION OF THE PROBLEMS CAUSED BY WATERLOGGING AND EXCESS SALINITY. AN AGRICULTURAL SYSTEM IS DEFINED AND DESCRIBED IN TERMS OF WATER DELIVERY, WATER USE, AND REMOVAL AND DRAINAGE SUBSYSTEMS. THE GENERAL CONCEPT OF WATER AND SALT BUDGETING IS USED TO DEFINE DATA NEEDS AND TO IDENTIFY LINKAGES AMONG SYSTEM COMPONENTS. APPROPRIATE TECHNIQUES FOR MEASURING THE QUANTITY AND QUALITY OF RELEVANT SURFACE AND GROUND WATER FLOWS ARE THEN PRESENTED, WITH SPECIAL ATTENTION PAID TO THE FARM WATER-USE SUBSYSTEM THAT IS THE HEART OF THE IRRIGATED AGRICULTURAL ENTERPRISE. FINALLY, WATER AND SALT BUDGETS FOR EACH SUBSYSTEM AND FOR THE SYSTEM AS A WHOLE ARE DEVELOPED AND PRESENTED.