Good number of commercial organic fertilizers are now registered at the Fertilizer and Pesticides Authority (FPA). Last year, the FPA listed 23 brands registered for rice fertilization. Apparently, the manufacturers of these brands claim that their products can effectively provide the nutrient needs of rice, especially under irrigated and rainfed lowland conditions.
How true is their claim?
The answer to this question could come from a paper by Dr. Cezar P. Mamaril and Michelle B. Castillo, which was presented during the recent 22nd National Rice R&D Conference at the Philippine Rice Research Institute (PhilRice) in Science City of Munoz, Nueva Ecija.
Dr. Mamaril, a retired soil science professor at the University of the Philippines Los Banos (UPLB) and retired soil scientist at the International Rice Research Institute (IRRI), said that first and foremost processed organic fertilizers as well as plant biomass (straws, stovers, leaves), animal manure and food processing wastes are sources of soil organic matter.