A series of experiments were conducted at different ecological regions in Jiansu Province, including Kunshan City(Yushan Towm) and Xishan(Yangjian Town) in Taihu area, Taixing City (Gensi Towm) in area along Yangtze Rive with high sand soil, Gaoyou City (Gaoyou Towm) and Jianhu County(Shanggang Towm) in Lixiahe area and Donghai County(Pingming Towm) in Huaibei area, during 2000-2001. For calculating the total amount of N application, three parameters of Stanford formulae, i.e. N requirement of t...