PEMANFAATAN Azolla mycrophylla SEBAGAI FITOREMEDIASI BESI (Fe) DALAM PENINGKATAN PRODUKTIVITAS PADI SAWAH (Oryza sativa L) PADA LAHAN BARU DIBUKA DI DESA MUARA KELANTAN KEC.SUNGAI MANDAU KAB.SIAK PROP. RIAU

Objective The research is to analyze the value of Azolla mycrophylla biomass growth from different cultivation management, analyze the mitigation of Fe poisoning on rice growth and production, develop the potential of Azolla mycrophylla in increasing rice productivity. rice fields. The results of the study can be concluded that Azolla mycrophylla is an adaptive aquatic fern and has the potential to be developed in Riau Province, the productivity of newly opened Ultisol rice fields with high iron content can be increased by using Azolla mycrophylla and rice husk biochar amelioration materials. The general conclusion is based on several conclusions from several experiments that have been conducted: Cultivation of Azolla mycrophylla at different shading percentages provides the best biomass growth at a water depth of 5.0 cm with high temperature and sunlight intensity conditions without shading. These findings not only advance our understanding of Azolla cultivation but also encourage continuous research and development of sustainable agricultural practices. Utilizing the nitrogen potential of Azolla provides an opportunity to contribute to an environmentally conscious and economically sustainable agricultural ecosystem, reduce the environmental impacts associated with synthetic fertilizers and strengthen food security, Periodic flooding significantly affects the growth and yield of rice ( Oryza sativa L.) on newly opened Ultisol soils, which are characterized by high acidity (pH 4.70) and Fe²⁺ concentration (4881 ppm). The two-week flooding–two-week drying treatment produced the highest rice productivity, which was not significantly different from continuous flooding, with improvements in plant height, number of tillers, and grain weight. The use of Azolla mycrophylla with 20 tons/ha of rice husk biochar showed the best rice productivity. The potential of Azolla mycrophylla combined with 20 tons/ha of rice husk biochar is able to increase rice productivity with its ability to reduce Fe toxicity in newly opened rice fields with high Fe solubility.