Supplementation of Inorganic Fertilizer by Black Soldier Fly Frass Enhances Plant growth, Yield, and Economic Return of Yellow Corn (Zea mays var. indenata)

The rising cost of synthetic fertilizers, driven by increasing raw material prices, poses a significant challenge to corn farmers and national food security. As a sustainable alternative, black soldier fly frass (BSFF) offers promise due to its nutrient-rich composition and lower production cost. This study evaluated the agronomic and economic potential of BSFF as an organic fertilizer for yellow corn (Zea mays var. indenata) under a randomized complete block design (RCBD) with six treatments: T1 (control), T2 (100% inorganic fertilizer or IF), T3 (100% BSFF), T4 (75% BSFF + 25% IF); T5 (50% BSFF + 50% IF); and T6 (25% BSFF + 75% IF), with three replications. The results revealed that T6, although slightly behind T2 in plant height, leaf number, and tasseling and silking times due to the immediate nutrient availability of IF, achieved comparable ear length, diameter, and grain yield. Economically, T6 produced the highest net benefit, surpassing T2 by 10.77%. These findings suggest that partial substitution of synthetic fertilizer with BSFF can be a cost-effective and sustainable strategy without significantly compromising productivity.