To Thi Thu Ha creator Hansen, Gunner Kjer Chairperson Salokhe, Vilas M. Examination Committee Preeda Pakpian Examination Committee DANIDA, Government of Denmark, Scholarship donor text series technical report th Bangkok Asian Institute of Technology 1998 continuing eng 114 leaves Vietnam is an agriculture-based country and the majority of its population depends on agriculture for their livelihood. The Red River Delta in Vietnam uses very intensive and diversified cropping systems but is constrained with limited land resources. To use the available land resources judiciously and efficiently, this study was undertaken to optimize the cropping system by using crop simulation models based on the survey data from farmers in Gia Lam district in Hanoi province and Nam Sach district in Hai Hung province in the Red River Delta. CERES-Rice and CERES-Maize of DSSAT3 computer software were used for evaluation and application of the crop model. The crop pattern, crop varieties, and fertilizer management practices are different in Gia Lam and Nam Sach. The relation between observations made from experimental (Ye) and simulated (Ys) results was expressed by equation Ys = 0.99*Ye for rice and Ys = 0.99*Ye for maize. Simulated double rice crop indicated that it would be advisable to adopt short duration variety in spring season and long duration variety in summer season. The optimum nitrogen level was found out to be 130 and 100 kg N/ha in combination with 5 ton FYM/ha in spring and summer season, respectively. Irrigation requirement was found out to be around 150 mm in summer season and 100 mm in spring season. So it could be concluded that crop simulation model can be useful tool together with experiments for optimization crop management in the Red River Delta region in Vietnam A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1998 Cropping systems Vietnam Red River Delta Cropping systems Simulation methods Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B13210 http://203.159.5.9/ait-thesis/detail.php?q=B13210 160499 20260818112641.0