Aims: This research objective was to determine productivity of two rice varieties using ratoon system through regulation of N fertilizer application at two flooding types in tidal lowland area.
Place and Duration of Study: The study was conducted from February to July 2020 at two locations in tidal lowland area, i.e. B-type flooding located at -203859, 132S 10404428,449E and C-type flooding located at -203858,81S 10404426,745E in Mura Sugih Village, Tanjung Lago Subdistrict, Banyuasin District, South Sumatra, Indonesia.
Study Design: The experimental design used in this study was Factorial Randomized Block Design with two treatments factors and four replications. The variety treatments (V) were consisted of V1: Inpari 30 and V2: Hipa 5 Ceva. N fertilizer application treatments (A) were consisted of A1: N fertilizing: 1/3 dose at planting period + 1/3 dose at 42 dap + 1/3 dose at 1 day after harvest (dah) of main crop; A2: N fertilizing: 1/3 dose at planting period + 1/3 dose at 42 dap + 1/6 dose at 1 dah of main crop + 1/6 dose at 21 dah of main crop.
Result: The results showed that N fertilizer application regulation can increase productivity of two rice varieties using ratoon system at two flooding types land in tidal lowland area. Productivity of rice hybrid (Hipa 5 ceva) tend to be higher than that of rice inbred (Inpari 30) using ratoon system at two flooding types land in tidal lowland area. Productivity of two rice varieties using ratoon system tend to be higher at B-flooding type land than that of C- flooding type land.