Abstract
Purpose: This research investigated sustainable agricultural practices focusing on the utilization of wastewater and underutilized organic nutrient sources. The study explores the cultivation of nitrogen-rich sources such as Spirulina and Azolla using wastewater as a growth medium, aiming to reduce production costs and address water scarcity problems. Additionally, a low-cost organic fertilizer (LOF) was developed using underutilized resources like Palmyrah leaves, Coconut leaves, and Banana pseudostem, with Spirulina, and Azolla aiming to counteract the detrimental effects of inorganic fertilizers and contribute to the circular economy by converting waste into valuable agricultural inputs.
Methods: Experimental trials assessed the efficacy of wastewater as a growth medium for Spirulina and Azolla, alongside evaluating the impact of organic nutrient sources on seed germination and seedling vigor. Pot experiments were conducted to assess biomass yield and crop growth parameters across various fertilizer treatments, including conventional organic, LOF, and inorganic methods.
Results: Results reveal that treatments containing wastewater significantly enhanced the biomass yield of Spirulina and Azolla compared to standard methods, offering a cost-effective solution. The LOF enhanced the seed germination (5-15%), and seedling vigor (12-53%) of selected seeds compared to the control. Pot experiment revealed that the combination treatments of LOF gave improvements in crop growth parameters, biomass yield, and nutrient content of Sugargraze (Hybrid sweet sorghum) compared to conventional organic or inorganic treatments. Notably, substituting 50% of organic or inorganic fertilizer with LOF gave comparable or higher performance, highlighting the potential of LOF as an environmentally sustainable alternative.
Conclusion: Overall, this study underscores the feasibility of integrating underutilized organic nutrient sources and wastewater utilization in sustainable agriculture.