Abstract: 【Objective】This study was designed to develop a spatial and dynamic knowledge model for suitable cultivars and sowing time of maize. 【Method】Applying the knowledge engineering method and mathematical modeling technique, a dynamic knowledge model for suitable cultivars in maize was established by quantitatively calculating the relationship of the cultivar characteristics to environmental factors and production requirement. The knowledge model for suitable sowing time is based on the synchronization between the maize growing process and the suitable season. 【Result】Cases were studied on the suitable cultivars selection model with data sets of eight typical cultivars and three different eco-sites, such as Beijing, Ji'nan, Shenyang, and on suitable sowing time decision model with data sets of a typical cultivar and three different eco-sites as well. 【Conclusion】 The result indicated a good performance of the knowledge model in decision-making and wide applicability.

Key words: Maize (zea mays), Sowing time, Knowledge model