Sustainable methods for growing turmeric: Evaluating the effects of synthetic and organic fertilizers on vegetative and reproductive attributes

Abstract

This study aimed to assess the influence of various biofertilizer sources on turmeric (Curcuma longa L.) cultivation in Eastern Nepal. The research was conducted at G.P Koirala College of Agriculture and Research Centre, Sundarharaicha, Morang, Nepal, from April 2023 to January 2024. The experiment utilized a randomized complete block design (RCBD) with seven treatments including T1: Recommended dose (RD) of NPK, T2: Goat manure (GM), T3: Organic manure (OM), T4: Poultry manure (PM), T5: Vermicompost (VC), T6: Farmyard manure (FYM), T7: Control, replicated three times. Turmeric cultivation practices were implemented following standard agronomic procedures. The recommended dose of synthetic fertilizer, NPK, exhibited the highest enhancement across multiple vegetative and reproductive growth parameters of turmeric, with notable increases in plant height, leaf number, tillers per plant, primary and secondary fingers per clump, fresh rhizome yield, dry yield, and dry recovery percentage. Among the organic sources, goat manure and poultry manure also showed promising results in enhancing turmeric yield and quality. Specifically, NPK recorded the highest fresh rhizome yield at 21.30 tons ha-1, while goat manure and poultry manure yielded 20.35 tons ha-1 and 18.69 tons ha-1, respectively. In contrast, the lowest fresh rhizome yield was observed in the control group, indicating minimal enhancement in yield without fertilizer supplementation. The results highlight how organic farming methods may be a good substitute for traditional chemical fertilizers in the context of sustainable turmeric production.