Response of Black, Red, and White Rice (Oryza sativa L.) Cultivars to Nutrient Management Under Highly Alkaline Soil

Abstract

Increasing rice productivity under highly alkaline soil is possible by using appropriate cultivars and efficient nutrient management. This study determined the agronomic and yield response of three rice cultivars to nutrient management under highly alkaline soil. It evaluated rice production's profitability using three rice cultivars influenced by nutrient management under highly alkaline soil. The experiment was laid out in a split-plot arranged in an RCBD with rice cultivars as the main plot and nutrient management as the subplot. Statistical analysis revealed that fertilized plants headed and matured earlier than unfertilized plants. A significant interaction effect was noted among rice cultivars under different nutrient management. The combination of organic and inorganic fertilizers increased the percentage of filled spikelets while reducing unfilled spikelets. Application of 2.5 t/ha-1 poultry litter + 60-30-30 kg ha-1 N, P O , and K O (T ), significantly increased the 2 5 2 4 number of productive tillers, the weight of grains hill-1, and grain yield (t/ha-1) compared to plants applied with pure inorganic fertilizer. For cost and return analysis, black rice and T achieved the highest gross margins of PHP 297,708.28 4 and PHP 269,845.68 respectively. The results indicated that using black rice applied with 2.5 t/ha-1 poultry litter + 60-30-30 kg ha-1 N, P O , and K O (T ) is a highly effective 2 5 2 4 and profitable option for lowland rice production under highly alkaline soil.