Abstract

Buri Mohammed Moro*, Issaka Roland Nuhu, Essien Ato and Biney Nathanial

Nitrogen is not only a major nutrient but most often the most limiting nutrient element in lowland ecologies. With the introduction of improved soil and water management ('sawah system) for lowland rice production, a study was conducted to determine the optimum nitrogen rate required. A randomized complete block design arranged in a split plot consisting of five levels of nitrogen as main treatments and three improved rice varieties as sub-treatments was adopted. Results showed that total number of tillers per m2 increased significantly with increasing levels of N as was total dry matter production. However, total number of panicles did not show the same relationship. Total biomass yield increased significantly and linearly with increasing levels of N. Paddy yield significantly increased from 1.7t ha-1 (control) to a maximum of 9.4t ha-1 (90kgN ha-1 ) before declining to 5.8 t ha-1 (150kgN ha-1 ) in the order: 0 < 30 < 60 < 150 < 120 < 90kgN ha1 respectively. This result significantly and positively reflected on grain harvest index (GHI) in the order: 0.27 < 0.38 < 0.46 < 0.47 < 0.57 < 0.68 for 0, 30, 60, 150, 120 and 90kgNha-1 respectively. Nitrogen at 90 kgN ha1was therefore recommended.