Determination of optimum and maximum nitrogen fertilizer rate for hybrid rice production in lowland ecosystem [manuscript]
Date
2020
Authors
Kristal Joy R. Bondoc
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Abstract
The study aimed to (i) determine the response of hybrid rice to increasing levels of N fertilizer and (ii) determine the optimum and maximum rate of N fertilizer for hybrid rice production. The experiment was conducted at farm of College of Agriculture and was laid out using Randomized Complete Block Design (RCBD). The treatments were Control (No Nitrogen Fertilizer with Recommended rate of P and K). Recommended Rate of P and K (0-60-90 kg P2O5-K2O/ha) + 50 kg of N/ha, Recommended Rate of P and K (0-60-90 kg P2O5-K2O/ha) + 100 kg of N/ha, Recommended Rate of p and K (0-60-90 kg P2O5-K2O/ha) + 150 kg of N/ha, Recommended Rate of P and K (0-60-90 kg P2O5-K2O/ha) + 200 kg of N/ha and Recommended Rate of P and K (0-60-90 kg P2O5-K2O/ha) + 250 kg of N/ha. Plant height st 60 DAT and at harvest was significantly improved by increasing levels of N while no significant differences was obtained for number for productive tillers, percent filled grains per panicle, grain yield and dry matter yield.
Inconclusive result on grain yield and other parameters may be due to contamination brought by the use of irrigation water coming directly from the rice paddies which is applied by the recommended level of N. It can be recalled that water accidentally overflowed to the treated plots. Contamination by N fertilizer lead to the increased outcome of the experiment especially the untreated plants which is beyond the control of the researcher. The R2 value of 0.617 reflects the closeness of the estimated regression live with the actual observed values. This also means that the increase in yield is accounted for by the increase in the level of Nitrogen. The maximum yield as computed is 8,873.3 kg/ha.