Environmental performance of nephrolepis as natural nitrate accumulator: a life cycle perspective in smallholder oil palm ecosystem

Abstract

This study investigated the environmental performance of Nephrolepis as a natural nitrate accumulator in smallholder oil palm ecosystems through a life cycle assessment approach. The research was conducted in Surya Indah Village, Pelalawan-Riau Regency, from January to May 2024, comparing natural (T1) and enhanced (T2) treatments across three blocks. Results demonstrated that enhanced treatment significantly improved Nephrolepis biomass production (389.8 g/m² compared to 305.3 g/m² in natural conditions) and nitrogen accumulation capacity (2.58% in fronds under enhanced conditions versus 2.34% in natural conditions). Soil analysis revealed that Nephrolepis cultivation effectively reduced nitrate leaching, with enhanced treatment showing the lowest soil nitrate concentrations (8.2 mg/kg in topsoil) compared to cleared treatments (18.6 mg/kg). Life cycle impact assessment indicated that enhanced management practices resulted in lower environmental impacts across all categories, with reduced global warming potential (382.4 kg CO2 eq/ha/year), eutrophication potential (2.68 kg PO2 eq/ha/year), and water depletion (228.4 m³/ha/year). These findings suggest that integrating Nephrolepis into smallholder oil palm systems, particularly under enhanced management practices, offers a promising approach for improving nutrient management while reducing environmental impacts in oil palm ecosystems.