Main Article Content
Phosphorus is one macronutrient that commonly gets fixed and accumulates into soils after it has been in use for long, thus becoming readily unavailable to plants in subsequent years. Such scenario is ontological in Mwea where rice farming is practiced, yet this element is one main critical nutrient that plants cannot do without for they need it for root initiation, root development, photosynthesis, grain- formation, grain-filling, as well as yielding. In that view therefore, an experiment was undertaken in Mwea irrigation scheme with the aim of investigating on the influence of phosphorus levels on yield components and grain yield of Nerica 4 and 11. The experiment was laid out in a Randomized Complete Block Design in split-plot arrangement replicated thrice. Two rice varieties (Nerica 4 and Nerica 11) formed main plots and phosphorus levels (0 kg P/ha, 25 kg P/ha, 50 kg P/ha and 75 kg P/ha) formed split plots. Data was collected on appropriate parameters between week 4 and 19 after sowing at intervals of three weeks. Results demonstrated that phosphorus levels significantly influenced the 1000-grain weight and number of panicles in the tested varieties. Additionally, Grain yield mean variation was observed, where highest grain yield of 0.988 tons per hectare was produced in Nerica 4 on 50 kg P/ha in season 2, while least grain yield of 0.831 tons per hectare was still produced in the same variety on control in season 1, thus 50 kg P/ha on Nerica 4 is recommended for rice farming in Mwea. The study would be used as a body of guidelines and information for judicial, responsible, and promotion of prescribed application of phosphates in Nerica rice farming at planting for realization of higher yields between the two Nerica varieties (Nerica 4 and 11) in Mwea and with like agro ecological areas.